10.2. Alphabetical Listing of Keywords [F-O]

Table 10.2: Alphabetical Listing of Keywords [F-O]

Keyword	Definition
FAZE Reactor Property	Specifies a fixed-phase constraint on the equilibrium calculation. Species that are initially in the gas phase will remain in the gas phase and species that are originally in a condensed phase (that is, bulk species) will remain in that condensed phase. If there is only one phase in the chemistry set, the phase constraint has no effect.
	Keyword Usage	Optional keyword. By default, phase equilibrium as well as composition equilibrium is determined.
	Reactor Models	Chemical and Phase Equilibrium Calculations
FGM_EXPORT Reactor Property	Write a Flamelet Generated Manifold file.
	Parameters	Optional/Reqd.	Units	Examples
	--	Required when writing an FGM file	--	FGM_EXPORT
	Keyword Usage	Optional.
	Reactor Models	Diffusion Flamelet Generator
FICA0 Inlet Property	The start of injection crank angle of the injection.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FICA0 main -21.5
	Crank angle	Required	degree	FICA0 main -21.5
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FIDUR Inlet Property	Duration of injection in number of crank angles of the injection.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FIDUR main 7.5
	Number of crank angle	Required	degree	FIDUR main 7.5
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FIEQM Reactor Property	Specify the eEQMqual-mass spray parcel formation option in the DI engine model. This option must be used together with the user-defined injection mass rate profile for the injection. By default, the spray parcels are formed and released at constant time interval; that is, the parcels might not have the same liquid mass if the injection rate profile is not constant. When the mass injection rate profile is uniform (that is, no user-profile is used), the spray parcels always contain the same liquid mass and are released at the same time interval.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required.	--	FIEQM pilot 1
	1	Required.	--	FIEQM pilot1 1
	Keyword Usage	Optional keyword. Default: OFF, that is, the spray parcels are created at the same time interval.
	Reactor Models	Direct Injection Diesel Engine Simulator
FILFY Inlet Property	Initial liquid fuel component mass fraction of the injection
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FILFY main decalin 0.5
	Liquid component name	Required	--	FILFY main decalin 0.5
	Mass fraction	Required	--	FILFY main decalin 0.5
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FIMAS Inlet Property	Total liquid mass of the injection.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FIMAS main 0.055
	Total injection mass	Required	g	FIMAS main 0.055
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FINJP Inlet Property	A piecewise-linear continuous profile can be used to describe a non-uniform injection rate profile. The piecewise profile should be given by a series of data points of normalized crank angle and injection rate pair. The normalized crank angle (CA) data must be arranged in ascending order from 0.0 to 1.0. The injection rate data are in arbitrary units and the direct injection (DI) engine model will rescale the injection rate data to match the total injection mass. By default, a uniform injection rate profile based on the total injection mass and the duration of injection is assumed.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FINJP injection1 0.5 0.75
	Crank angle	Required	--	FINJP injection1 0.5 0.75
	Injection rate	Required	--	FINJP injection1 0.5 0.75
	Keyword Usage	Optional keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FINRD Inlet Property	Number of divisions (rings) in the radial direction to be applied to the injection. The injection/spray is divided into parcels. The total number of parcels is determined by multiplying the number of divisions in the radial direction by the number of divisions in the time/injection direction.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FINRD main 10
	Number of divisions	Required	--	FINRD main 10
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FINTL Inlet Property	Number of divisions in the time/injection direction to be applied to the injection. The injection/spray is divided into parcels. The total number of parcels is determined by multiplying the number of divisions in the radial direction by the number of divisions in the time/injection direction.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FINTL main 10
	Number of divisions	Required	--	FINTL main 10
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FITMP Inlet Property	Initial liquid temperature of the injection.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FITMP main 345.5
	Liquid temperature	Required	K	FITMP main 345.5
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FIXT Reactor Property	Specifies a fixed-temperature boundary condition on the upper wall (only used for non-symmetric cartesian coordinates).
	Parameters	Optional/Reqd.	Units	Examples
	Temperature	Optional, if a temperature is not specified, the value of the inlet gas temperature will be used (TINL)	K	FIXT 400
	Keyword Usage	Optional keyword. By default, a zero temperature gradient is enforced if FIXT is omitted (adiabatic upper wall)
	Reactor Models	Planar Shear Flow Reactor
FLAM Reactor Property	Position and fixed-temperature value for calculating strained, lifted flames. In this case, the inlet gas velocity is calculated (rather than fixed) based on a fixed location of the flame front. The flame front location is specified by giving a location and value of a temperature (above the inlet temperature value) to fix at this position.
	Parameters	Optional/Reqd.	Units	Examples
	Flame position	Required	cm	FLAM 0.5700.
	Temperature	Required	K	FLAM 0.5 700.
	Keyword Usage	Optional keyword. By default, no temperature is fixed in the calculation.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
FLINJ Inlet Property	Assign an injection to an injector.
	Parameters	Optional/Reqd.	Units	Examples
	Injection name	Required	--	FLINJ modelX pilot1
	Injector name	Required	--	FLINJ modelX pilot1
	Keyword Usage	Reqired keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
FLRT Inlet Property	The mass flow rate into the reactor for an optionally specified inlet stream. For Premixed Laminar Flame calculations, this is mass flux at the inlet (mass flow rate per area) and there is no option for inlet stream name.
	Parameters	Optional/Reqd.	Units	Examples
	Inlet stream name (Not valid for Premixed Laminar Flames)	Optional If there is no stream name then the mass flow rate applies to the default or to all defined streams.	--	FLRT secondary_air 0.13
	Mass flow rate or Mass flux (for Premixed Laminar Flames)	Required	g/sec g/(cm² ⋅ sec)	FLRT secondary_air 0.13 FLRT 0.04
	Keyword Usage	PFRs and Monolith Reactors: Flow specification via one of VEL, VDOT, VDOTPRO SCCM SCCMPRO FLRT, or FPRO is required. PSRs and PaSRs: Optional keyword. If none of TAU, FLRT/FPRO, SCCM/SCCMPRO are specified or are nonzero, then a closed-system is assumed. FLRT/FPRO or SCCM/SCCMPRO is required for each INLET stream defined. Premixed Laminar Flames: Required keyword. Stagnation Flow CVD Reactors: FLRT / FPRO or SCCM / SCCMPRO or UINL is required for each inlet stream defined. Rotating Disk CVD Reactors: Optional keyword.
	Reactor Models	Honeycomb Monolith Reactor Non-reactive Gas Mixer Partially Stirred Reactor (PaSR) Perfectly Stirred Reactor (PSR) Plasma PFR Plasma PSR Multiphase PSR Plug Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
FLTB_FGM Reactor Property	Specifies the name of the Flamelet Generation Manifold (FGM) file.
	Parameters	Optional/Reqd.	Units	Examples
	FGM file name	Required when writing an FGM file	--	FLTB_FGM Diffusion_FGM.fla
	Keyword Usage	Optional.
	Reactor Models	Diffusion Flamelet Generator
FLT_NPOINTS Reactor Property	Species number of grid points in the progress-variable space.
	Parameters	Optional/Reqd.	Units	Examples
	Number of progress variable points	Required when writing FGM file	--	FLT_NPOINTS 50
	Keyword Usage	Optional. The default value is 50.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame
FLT_PVSPEC Reactor Property	Species name and its mass-fraction weighting factor to be used in the calculation of the rate-of-progress variable when generating flamelet tables (for premixed flames).
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Required	--	FLT_PVSPEC CO21.2
	Mass-fraction weighting factor	Required	--	FLT_PVSPEC CO2 1.2
	Keyword Usage	Required keyword when generating flamelet table.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
FLTB Output	Export one-dimensional flamelet tables in the standard flamelet format to the specified file. The file will be created in the working directory.
	Parameters	Optional/Reqd.	Units	Examples
	Flamelet table filename	Required	--	FLTB flamelet.txt
	Keyword Usage	Optional keyword. By default, no flamelet table is exported. The name of the flamelet table file generated is FileName_1.FileExt (where FileName is the user-provided name; FileName= flamelet and FileExt=txt in the example given here.) When continuations are used, the filename is appended with "_n" where n is the continuation number+1 . For extinction studies, the flamelet files are generated based on input "Step Interval for Saving (EXT_SAVEINT)". Thus, " _n" in the flamelet filename generated in the extinction study indicates the (total steps/EXT_SAVEINT).
	Reactor Models	- Opposed-flow Flame Simulator
FLUX Reactor Property	This keyword indicates that a flux balance will determine the mass fractions of the species at the inlet (rather than a fixed composition). If FLUX is specified, the REAC keywords are used to determine the convective mass flux in, which is balanced against diffusive fluxes to dynamically determine the inlet gas composition. See Equation 15–21 of the Chemkin Theory Manual .
	Keyword Usage	Optional keyword. By default, a flux balance is solved at the inlet. See also COMP.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
FLXB Reactor Property	Use extrapolation to obtain species mass fractions at the outflow (or hot) boundary. By default, PREMIX assumes all species have zero mass fraction gradients at the outflow boundary. However, for pollutant species such as NO, their concentrations are still growing in the post flame region so that their mass fraction profiles have positive gradients at the outflow boundary. The extrapolation boundary condition provides a proper outflow treatment when mass fraction gradients are not zero at the outflow boundary.
	Keyword Usage	Optional keyword. By default, zero mass fraction gradient is used as outflow boundary condition
	Reactor Models	Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation
FPRO Inlet Property Profiles	Used to specify a transient profile or function of mass flow rate vs. time for an inlet stream. The profile specified will be interpolated linearly from the FPRO points provided.
	Parameters	Optional/Reqd.	Units	Examples
	Inlet stream name	Optional If there is no stream name then the reactant and mole fraction apply to all streams.	--	FPRO purge 0.19 29.0
	Time	Required	sec (cm for flow reactors)	FPRO 0.1929.0
	Flow rate	Required	g/sec	FPRO 0.19 29.0
	Keyword Usage	PFRs and Monolith Reactors: Flow specification via one of VEL, VDOT, VDOTPRO SCCM SCCMPRO FLRT, or FPRO is required. PSRs and PaSRs: Optional keyword. If none of TAU, FLRT / FPRO, SCCM / SCCMPRO are specified or are nonzero, then a closed-system is assumed. FLRT / FPRO or SCCM / SCCMPRO is required for each INLET stream defined. Premixed Laminar Flames: Required keyword. Stagnation Flow CVD Reactors: FLRT / FPRO or SCCM / SCCMPRO or UINL is required for each inlet stream defined. Rotating Disk CVD Reactors: Optional keyword.
	Reactor Models	Honeycomb Monolith Reactor. Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Plasma PFR Plasma PSR Multiphase PSR Plug Flow Reactor (PFR) Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
FREE Reactor Property	Specifies that the equilibrium species composition will be calculated. See also FROZ.
	Keyword Usage	Optional keyword. By default, the composition will be calculated.
	Reactor Models	Chemical and Phase Equilibrium Calculations
FREE Reactor Property	Specifies the problem type, which will be to solve for a freely propagating flame to determine flame speed.
	Keyword Usage	Required keyword.
	Reactor Models	Premixed Laminar Flame-speed Calculation
	Notes	The problem-type can be changed for a restart run. See also BURN.
FROZ Reactor Property	Specifies that species composition will be frozen or fixed during the equilibrium calculation. See also FREE.
	Keyword Usage	Optional keyword. By default, the composition will be calculated.
	Reactor Models	Chemical and Phase Equilibrium Calculations
FUEL Inlet or Reactor Property	Defines the fuel mole fraction composition for an inlet stream in an open system or for the initial conditions in a closed system, when an equivalence ratio is specified ( EQUI). It must be followed by a species name and then the mole fraction. One of these FUEL inputs must appear for each fuel species, which are used to determine the inlet composition based on an equivalence-ratio calculation. Any given species can participate simultaneously as a fuel, oxidizer, or product. The sum of all the fuel mole fractions should equal one. If it does not, a warning message will be printed and the mole fractions will be normalized so the sum does equal one.
	Parameters	Optional/Reqd.	Units	Examples
	Inlet stream name (PSRs only)	Optional If there is no stream name than the fuel mole fraction compassion applies to the default or all defined streams.	--	FUEL mixture1 C2H2 0.5
	Species name	Required	--	FUEL C2H20.5
	Fuel fraction	Required	mole fractions	FUEL C2H2 0.5
	Keyword Usage	Required keyword when EQUI option is used for an inlet stream or for the initial conditions in a reactor.
	Reactor Models	Closed Homogeneous Batch Reactor Honeycomb Reactor IC HCCI Engine Perfectly Stirred Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor SI Engine Zonal Simulator
	Notes	The mole fractions are of the fuel itself, not for the entire composition. The FUEL keywords must be changed as a set, not individually for a restart run. The FUEL keywords must be changed as a set, not individually for continuation run.
FVCP Reactor Property	Specify the piecewise linear profile of the friction velocity coefficient when the wall-function heat transfer correlation is used to compute wall heat loss rate. Note that Chemkin requires the friction velocity to be given in cm/sec. Although the friction velocity coefficient f should be dimensionless, users should scale its value to convert the units of the friction velocity to cm/sec. For more information about this heat transfer correlation, see the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	Crank angle	Required	degree	FVCP -120.2 10.0
	Friction velocity coefficient	Required	--	FVCP -120.2 10.0
	Keyword Usage	Optional keyword.
	Reactor Models	Multi-Zone HCCI Simulator IC HCCI Engine SI Engine Zonal Simulator
GASW Reactor Property	Estimated gas-phase mole fractions at the wall boundaries, which may be helpful to aid in convergence. The sum of all the GASW values should equal one. However, if they do not, a cautionary message will be printed and the mole fractions will be normalized so the sum does equal one. The actual gas mole fractions at each wall at the initial condition of the boundary-layer calculation will be calculated via the Twopnt procedure (unless the NOTP keyword appears).
	Parameters	Optional/Reqd.	Units	Examples
	Gas species name	Required	--	GASW SIH21.0E-4
	Mole fraction of gas species	Required	mole fractions	GASW SIH2 1.0E-4
	Keyword Usage	Optional keyword. By default, values given by the REAC keyword will be used.
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor
GDOT Reactor Property	This keyword may be used to specify explicitly the net surface production rates of gas-phase species at the substrate, instead of using Surface Kinetics. In order to use this option, the Surface Kinetics input file must be empty, which means that the number of surface reactions, surface site species and bulk species must all be zero in the Surface Kinetics input file.
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Required	--	GDOT H -1.3E-7
	Net surface production rate	Required	mole/cm²sec	GDOT H -1.3E-7
	Keyword Usage	Optional keyword. By default, the net surface production rate is 0.0.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
GEN Output	Controls the printing of general information about the chemistry set. It also controls the printing of summary tables about the reaction thermodynamics. The ALL option produces all of the general information tables. NONE will suppress this output. If only GEN is given on the input line, ALL is assumed (the default). The GEN information is printed by default unless explicitly turned off.
	Parameters	Optional/Reqd.	Units	Examples
	ALL option	Optional	--	GEN ALL
	NONE option	Optional	--	GEN NONE
	Keyword Usage	Optional keyword. By default, the table output is determined by the ALL or NONE keyword.
	Reactor Models	Mechanism Analyzer
GFAC Reactor Property	This keyword specifies that the rates of all gas-phase reactions will be multiplied (scaled) by the factor GFAC. This option is sometimes useful if convergence difficulties are encountered due to unusually large reaction rates. Using GFAC, the problem can first be first solved with artificially reduced reaction rates, which then can be increased in subsequent continuations or restarts until GFAC is one. In addition, setting GFAC and SFAC to zero for a perfectly stirred reactor simulation, enables the Non-reactive Gas Mixer Reactor Model.
	Parameters	Optional/Reqd.	Units	Examples
	Multiplier value	Required	--	GFAC 2.0
	Reactor number (PSR clusters only)	Optional If no number is given, values are assumed to apply to all reactors in a cluster.	--	GFAC 2.0 1
	Keyword Usage	General: Optional keyword. By default, the multiplier value is set to 1.0. `Non-reactive Mixer`: Required keyword, must be set to 0.0 to enable this Reactor Model.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Honeycomb Reactor IC HCCI Engine Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor SI Engine Zonal Simulator Stagnation Flow CVD Reactor
GMHTC Reactor Property	The reactor wall temperature will be obtained by solving energy conservation equation for the reactor wall. It uses the heat transfer coefficient between the inner wall surface and the gas mixture inside the reactor specified by `GMHTC`. The initial wall temperature is the surface temperature. When this option is used, all the external heat fluxes, that is, heat loss to the environment and heat exchange between the reactors in a network, are applied to the wall energy equation instead of the gas phase energy equation. The heat generated by the surface reactions will also be included in the wall energy equation.
	Parameters	Optional/Reqd.	Units	Examples
	Material name	Optional. If no material is specified, the same value will be used for all materials.	--	GMHTC material10.1
	Heat transfer coefficient	Required	cal/(cm²-K-sec)	GMHTC 0.1
	Reactor number (PSR clusters only)	Optional. If no number is given, the keyword is assumed to apply to all reactors in a cluster.	--	GMHTC material1 0.1 1
	Keyword Usage	Optional keyword. This keyword must be used with MMASS . By default, the wall energy equation will not be solved and the reactor wall temperature is equal to the gas temperature in the reactor unless the surface temperature is specified.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Honeycomb Monolith Reactor IC HCCI Engine Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Plasma PSR Plasma Plug Flow Reactor Plug Flow Reactor SI Engine Zonal Simulator
GRAD Reactor Property	Parameter that controls the degree of mesh adaptation based on the maximum first derivative, or gradient in the solution. A reasonable value is usually between about 0.1 and 1.0, where no adaptation based on gradient is specified with 1.0.
	Parameters	Optional/Reqd.	Units	Examples
	Gradient of mesh adaptation	Required	--	GRAD 0.5
	Keyword Usage	Optional keyword. By default, the gradient is set to 0.1.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	This keyword can be changed for a restart or continuation run. Steady-state 1-D Solution Methods of the Chemkin Theory Manual for more information.
GRAV Reactor Property	The value of the acceleration of gravity. The buoyancy term can only be included in the boundary-layer equations if gravity acts parallel to the principal flow direction. Thus, GRAV 980 may be used to describe flow vertically upward, or GRAV -980 for flow downward. Omitting this keyword neglects the buoyancy term.
	Parameters	Optional/Reqd.	Units	Examples
	Acceleration of gravity	Required	cm/sec²	GRAV -980
	Keyword Usage	Optional keyword. By default, the acceleration of gravity.is zero.
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor
GRID Reactor Property Profiles	Specifies a point on an initial grid. Up to NTOT of these GRID inputs can be included. Each GRID entry contains the spatial coordinate of a mesh point. The GRID keywords are a grouped list and the grid coordinates must appear in ascending order.
	Parameters	Optional/Reqd.	Units	Examples
	mesh point coordinate	Required	cm	GRID 0.0
	Keyword Usage	Optional keyword. If no GRID keywords are included, the grid will have equally spaced grid points based on the value of NPTS.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
GRXN Output	Prints out a table of reaction rates and other pertinent information for each gas-phase reaction. The ALL option is the default and produces tables for every gas-phase reaction. The NONE option suppresses output for all of the reactions. If reaction information is desired for only certain reactions, they may be optionally specified by their number (given in the Pre-processor output) or by typing an exact duplicate of the reaction expression (see example input).
	Parameters	Optional/Reqd.	Units	Examples
	ALL option	Optional, default is ALL	--	GRXN ALL
	NONE option	Optional, default is ALL	--	GRXN NONE
	Gas reaction number list	Optional, default is ALL	--	GRXN 2 5
	Gas reaction expression	Optional, default is ALL	--	GRXN CH4+H<=>CH3+H2
	Keyword Usage	Optional keyword. By default, the table output is determined by the ALL or NONE keyword.
	Reactor Models	Mechanism Analyzer
GTHB Output	Create an extra table of the reaction rates for those reactions that involve third bodies. This option employs the bath-gas composition (specified by the XBTH keyword) to yield effective reaction rates. The ALL option is the default and produces tables for every gas-phase reaction. The NONE option suppresses output for all of the reactions. If reaction information is desired for only certain reactions, they may be optionally specified by their number (given in the Pre-processor output) or by typing an exact duplicate of the reaction expression (see example input).
	Parameters	Optional/Reqd.	Units	Examples
	ALL option	Optional, default is ALL	--	GTHB ALL
	NONE option	Optional, default is ALL	--	GTHB NONE
	Gas reaction number list	Optional, default is ALL	--	GTHB 2 5
	Gas reaction expression	Optional, default is ALL	--	GTHB 2H+M<=>H2+M
	Keyword Usage	Optional keyword. By default, the table output is determined by the ALL or NONE keyword.
	Reactor Models	Mechanism Analyzer
GVEL Reactor Property	Activate the Woschni correlation for the average cylinder gas velocity. This keyword can only be used in conjunction with the ICHT keyword. Internal Combustion Engine Model of the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	C ₁₁ in the average gas velocity correlation	Required	--	GVEL 2.28 0.308 0.324 0
	C ₁₂ parameter in the Woschni correlation	Required	cm/(sec ⋅ K)	GVEL 2.28 0.308 0.324 0
	C ₂ parameter in the Woschni correlation	Required		GVEL 2.28 0.308 0.324 0
	Ratio of swirl velocity to mean piston speed	Required	--	GVEL 2.28 0.308 0.324 0
	Keyword Usage	Optional keyword. By default, the setting is GVEL 1 0 0 0.
	Reactor Models	IC HCCI Engine SI Engine Zonal Simulator
HIMP Reactor Property	Use the Huber correlation to calculate the characteristic gas velocity used by the Woschni heat transfer coefficient formulation.
	Parameters	Optional/Reqd.	Units	Examples
	IMEP	Required	atm	HIMP 10
	Keyword Usage	This keyword is optional and works when the Woschni heat transfer formulations (ICHT, ICHX, and ICHW) and the Woschni gas velocity correlation (GVEL) are also in use.
	Reactor Models	IC HCCI Engine Multi-Zone HCCI Engine SI Engine Zonal Simulator
HITE Reactor Property	The channel height (for cartesian coordinates), or the reactor radius ( cylindrical coordinates), or distance between the channel wall and the symmetry line for a symmetric planar channel.
	Parameters	Optional/Reqd.	Units	Examples
	Channel height or radius	Required	cm	HITE 2.0
	Keyword Usage	Required keyword.
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor
H0 Solver	The initial distance step size used by the transient solver.
	Parameters	Optional/Reqd.	Units	Examples
	Initial time step size	Required	cm	H0 1.0E-4
	Keyword Usage	Optional keyword. By default, the initial time step size is set to 1.0E-6.
	Reactor Models	Closed Multiphase Reactor Cylindrical Shear Flow Reactor Planar Shear Flow Reactor Multiphase PSR
HP Problem Type	Constant pressure and enthalpy constraints.
	Keyword Usage	Optional keyword. Exactly one problem type keyword must be included.
	Reactor Models	Chemical and Phase Equilibrium Calculations
	Notes	PH keyword is equivalent.
HSEN Output	Calculate the first-order, heat-of-formation sensitivity coefficients (that is, with respect to the gas-phase and surface species heats of formation) for species fractions and for other dependent variables in the system. Sensitivity results will be included in the XML Solution File.
	Parameters	Optional/Reqd.	Units	Examples
	String indicating for which variables sensitivity coefficients will be saved or printed. The string is a space-delimited list containing species names and any one of the following: ALL, AVEL, RVEL, CVEL, FLRT, or TEMP (see Notes)	Optional If no string is given, then ALL is assumed.	--	HSEN OH HSEN TEMP
	Keyword Usage	Optional keyword. By default, no sensitivity coefficients are computed or printed.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	This keyword can be added but not removed from a continuation or restart run See also EPSS, EPSG, EPST, SENG, and HSEN for other sensitivity options The optional parameter strings are defined as follows: ALL: all species and all other dependent variables in the solution AVEL: axial velocity (Plug Flow, Diffusion or Premixed Opposed-flow Flames, Rotating Disk, and Stagnation Flow CVD Reactors only) CVEL: circumferential velocity (Rotating Disk and Stagnation Flow CVD Reactors only) RVEL: radial velocity (Diffusion or Premixed Opposed-flow Flames, Rotating Disk, and Stagnation Flow CVD Reactors only) FLRT: mass flow rate (Premixed Laminar Flame-speed Calculation only) TEMP: gas temperature
HSWC Reactor Property	Specifies the crank angle when the entire wall heat loss will be switched from the unburned zone to the burned zone. HSWM , HSWT , and HSWC are mutually exclusive.
	Parameters	Optional/Reqd.	Units	Examples
	Crank angle	Required	degree	HSWC -0.4
	Keyword Usage	Optional keyword.
	Reactor Models	SI Engine Zonal Simulator
HSWT Reactor Property	Specifies the burned mass fraction value at which the entire wall heat loss will be switched from the unburned zone to the burned zone. HSWM , HSWT , and HSWC are mutually exclusive.
	Parameters	Optional/Reqd.	Units	Examples
	Temperature	Required	K	HSWM 0.05
	Keyword Usage	Optional keyword.
	Reactor Models	SI Engine Zonal Simulator
HSWM Reactor Property	Specifies the burned mass fraction value at which the entire wall heat loss will be switched from the unburned zone to the burned zone. HSWM , HSWT , and HSWC are mutually exclusive.
	Parameters	Optional/Reqd.	Units	Examples
	Burned mass fraction	Required	--	HSWM 973.15
	Keyword Usage	Optional keyword.
	Reactor Models	SI Engine Zonal Simulator
HTC Reactor Property	The overall, per-area, heat-transfer coefficient for convective or conductive heat transfer out of the system. This keyword is only relevant when the energy equation is being solved.
	Parameters	Optional/Reqd.	Units	Examples
	Material name	Optional. If no material is specified, the same value will be used for all materials.	--	HTC material1 1.E-4
	Heat transfer coefficient	Required	cal/(cm² -K-sec)	HTC material1 1.E-4
	Reactor number (PSR clusters only)	Optional. If no number is given, the keyword is assumed to apply to all reactors in a cluster.	--	HTC material1 1.E-4 1
	Keyword Usage	Optional keyword. This keyword must be used with TAMB. By default, the heat loss from the reactor will be zero. See also QLOS and QPRO .
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Honeycomb Monolith Reactor IC HCCI Engine Multi-Zone HCCI Engine Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Plasma PSR Plasma Plug Flow Reactor Multiphase PSR Plug Flow Reactor SI Engine Zonal Simulator
HTCPRO Reactor Property Profiles	The profile of the overall heat transfer coefficient for convective or conductive heat transfer out of the system. Each HTCPRO entry represents a point in a piecewise-linear profile. The keyword is only relevant when the energy equation is being solved.
	Parameters	Optional/Reqd.	Units	Examples
	Time or Distance value (depending on Reactor Model)	Required	sec or cm	HTCPRO 5.0E-5 2.0
	Heat transfer coefficient per area	Required	cal/cm²-K-sec	HTCPRO 5.0E-5 2.0
	Reactor number (PSR clusters only)	Optional If no number is given, the profile described by the first two values is assumed to apply to all reactors in a cluster.	--	HTCPRO 5.0E-5 2.0 1
	Keyword Usage	Optional keyword. By default, there is no heat loss from the reactor. See also HTC, QLOS, HTRN, and QFUN.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Closed Multiphase Reactor Cylindrical Shear Flow Reactor Honeycomb Reactor IC HCCI Engine Multi-Zone HCCI Engine Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Plasma Plug Flow Reactor Multiphase PSR Plug Flow Reactor SI Engine Zonal Simulator
HTRN Reactor Property	The heat transfer coefficient and ambient temperature for specification of the heat loss from the reactor along the external surface area, at an optionally specified surface material. This keyword is only relevant when the energy equation is being solved.
	Parameters	Optional/Reqd.	Units	Examples
	Material name (0-D and Plug Flow systems only)	Optional If no material is specified, the same value will be used for all materials.	--	HTRN material1 1.E-4 298
	Heat transfer coefficient	Required	cal/(cm²⋅ K ⋅ sec)	HTRN 1.E-4 298 HTRN 1.E-4
	Ambient temperature (0-D and Plug Flow systems only)	Required	K	HTRN 1.E-4 298
	Reactor number (PSR clusters only)	Optional If no number is given, the keyword is assumed to apply to all reactors in a cluster.	--	HTRN material1 1.E-4 298 1
	Keyword Usage	Optional keyword. By default, the heat loss from the reactor will be zero. See also QLOS and QPRO.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Honeycomb Reactor Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor
ICHF Inlet Property	Use the wall function heat transfer correlation to compute the wall heat loss rate for the internal-combustion engine models. For more information about this heat transfer correlation, see the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	Dimenstionless temperature inside tubulent thermal boundary layer	Required.	--	ICHF 100.0 0.125 400.00
	Exponent of the viscosity ratio	Required	--	ICHF 100.0 0.125 400.0
	Wall temperature	Required	K	ICHF 100.0 0.125 400.0
	Keyword Usage	Optional keyword.
	Reactor Models	Multi-Zone HCCI Simulator IC HCCI Engine SI Engine Zonal Simulator
ICHH Reactor Property	Use the Hohenberg formulation to calculate cylinder wall heat transfer coefficient.
	Parameters	Optional/Reqd.	Units	Examples
	parameter_a	Required	--	ICHH 130.0 -0.06 0.8 -0.4 1.4 400.0
	parameter_b	Required	--	ICHH 130.0 -0.06 0.8 -0.4 1.4 400.0
	parameter_c	Required	--	ICHH 130.0 -0.06 0.8 -0.4 1.4 400.0
	parameter_d	Required	--	ICHH 130.0 -0.06 0.8 -0.4 1.4 400.0
	parameter_e	Required	m/s	ICHH 130.0 -0.06 0.8 -0.4 1.4 400.0
	ambient_temperature	Required	K	ICHH 130.0 -0.06 0.8 -0.4 1.4 400.0
	Keyword Usage	This keyword is optional and works with IC engine models only. All IC engine heat transfer coefficient options (ICHT, ICHX, ICHW, ICHH, HTC, HTCPRO, and QFUN) are mutually exclusive. Default: the Hohenberg heat transfer coefficient formulation is NOT used.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Honeycomb Reactor IC HCCI Engine Multi-Zone HCCI Engine Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor SI Engine Zonal Simulator
ICEN Reactor Property	The transient internal combustion (IC) HCCI engine model will be implemented. The solution will be obtained with the volume as a function of time, where the function of time is determined by an engine model that defines the volume as a function of user-specified engine parameters. The equations solved are those of a specified volume function of time, but the user does not need to provide a subroutine or volume vs. time profile for this calculation. This problem type is only allowed for closed (zero flow-rate) systems.
	Keyword Usage	Optional keyword. By default, a constant pressure, constant volume, steady-state problem is assumed.
	Reactor Models	IC HCCI Engine
	Notes	See also: CMPR, VOLC, RPM, and LOLR keywords. SI Engine Zonal Simulator
ICHT Reactor Property	Convective heat transfer correlation for the transient IC HCCI Engine model, using the following generalized convective heat transfer correlation: . Where is the Nusselt number for heat transfer, is the Reynolds number, and is the Prandtl number. For more information on the usage of these parameters, see Internal Combustion Engine Model of the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	The value `a` in heat transfer correlation	Required	dimensionless	ICHT .035.5 .33 10. 350.
	The value `b` in heat transfer correlation	Required	dimensionless	ICHT .035 .5.33 100 350.
	The value `c` in heat transfer correlation	Required	dimensionless	ICHT .035 .5 .33 10. 350.
	Bore diameter	Required	cm	ICHT .0350.5 .33 10. 350.
	Wall temperature	Required	K	ICHT .035 .5 .33 10. 350.
	Keyword Usage	Optional keyword. By default, an adiabatic (zero heat loss) condition is assumed. See also GVEL for Woschni correlation extensions.
	Reactor Models	IC HCCI Engine SI Engine Zonal Simulator
ICHW Reactor Property	Use the dimensional Woschni formulation to calculate cylinder wall heat transfer coefficient.
	Parameters	Optional/Reqd.	Units	Examples
	parameter_a	Required	--	ICHW 3.26 0.8 -0.53 400.0
	parameter_b	Required	--	ICHW 3.26 0.8 -0.53 400.0
	parameter_c	Required	--	ICHW 3.26 0.8 -0.53 400.0
	ambient_temperature	Required	K	ICHW 3.26 0.8 -0.53 400.0
	Keyword Usage	This keyword is optional and works with IC engine models only. All IC engine heat transfer coefficient options (ICHT, ICHX, ICHW, ICHH, HTC, HTCPRO, and QFUN) are mutually exclusive. By default, the dimensional Woschni heat transfer coefficient formulation is NOT used.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Honeycomb Reactor Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor
ICRD Reactor Model or Reactor Property	Flag to specify coordinate system, which determines the Reactor Model and symmetry assumptions for shear-layer flow.
	Parameters	Optional/Reqd.	Units	Examples
	Coordinate flag indicating Planar Shear Flow Reactor, with, non-symmetric boundary conditions	Required	--	ICRD PLAN
	Coordinate flag indicating Planar Shear Flow Reactor, assuming symmetry with respect to the center axis	Required	--	ICRD SYMC
	Coordinate flag indicating Cylindrical Shear Flow Reactor, using radial coordinates	Required	--	ICRD RAD
	Keyword Usage	Required keyword.
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor
	Notes	Only one-half of the physical domain is used for the radial or symmetric channel case, and the lower boundary is the symmetry line
IEM Reactor Property	Flag indicating that the interaction-by-exchange-with-the-mean (IEM) model will be used to simulate the molecular mixing within the computational particle.
	Keyword Usage	Optional keyword. By default, a well mixed model is assumed.
	Reactor Models	Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR)
IGRIDMETHOD_n Reactor Property	Choice for the initial grid profile. Integer n can be 1, 2, or 3 and mean uniform grid, biased grid, and read from an input file, respectively. In general, the uniform grid is not very useful and a biased grid should be used. The bias is created with respect to the location of the stoichiometric mixture fraction.
	Keyword Usage	Required keyword. The default value is IGRIDMETHOD_2, indicating a biased grid.
	Reactor Models	Diffusion Flamelet Generator
INIT Reactor Property	The initial gas mole fraction of the given species in the reactor for a transient simulation. There may be as many INIT lines as there are species in the problem.
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Required	--	INIT N20.79
	Gas fraction	Required	Mole fraction	INIT N2 0.79
	Keyword Usage	Optional keyword. By default, if no INIT entries are made, the inlet gas properties will be used. When some INIT entries are present, species not explicitly entered are taken as having a mole fraction of 0.
	Reactor Models	Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR) Normal Incident Shock Normal Reflected Shock Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
INJM Reactor Property	Total mass flow rate of the injected gas. See Equation 15–5 of the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	Mass flow rate	Required	g/(cm² ⋅ sec)	INJM 0.15
	Keyword Usage	Required keyword when INJS is used; otherwise it is ignored.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
INJS Reactor Property	Injection of gas species at a location along the axis of symmetry can be included using one or more INJS keywords. The injection is specified as a spatially distributed Gaussian source. INJM is the total mass flow, that is, the spatial integral of the mass flow function. This source term will be added to Equation 15–5 of the Chemkin Theory Manual . INJS specifies the species composition of the injected flow, in mole fractions.
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Required	--	INJS H20.5
	Species composition	Required	mole fractions	INJS H2 0.5
	Keyword Usage	Optional keyword. By default, there is no mass injection along the flow axis.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
INJT Reactor Property	Temperature of the injected gas.
	Parameters	Optional/Reqd.	Units	Examples
	Temperature	Required	K	INJT 300.
	Keyword Usage	Optional keyword. By default, no enthalpy is added to the energy equation with the injected gas. If INJS is not included, this keyword will be ignored.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
INJW Reactor Property	Half-width of the Gaussian gas-injection source. See Equation 15–5 of the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	Half-width	Required	cm	INJW 0.07
	Keyword Usage	Optional keyword. By default, the width is 0.0. Keyword is ignored unless INJS is present.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
INJX Reactor Property	Height above the disk which is the center of the Gaussian-shaped injection source. See Equation 15–5 of the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	Height	Required	cm	INJX 0.6
	Keyword Usage	Optional keyword. By default, the height is 0.0. Keyword is ignored unless INJS is present.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
INLET Reactor Property	Specification of a reactor inlet stream. Specify an optional name for the stream and a reactor number. For each INLET stream defined, you must also specify the corresponding inlet temperature ( TINL), composition ( REAC), or set of EQUI / OXID / FUEL / CPROD / ADD ), and flow rate ( FLRT or SCCM).
	Parameters	Optional/Reqd.	Units	Examples
	Inlet stream name	Required	--	INLET secondary_air2
	Reactor number (PSR clusters only)	Optional If no number is given, values are assumed to apply to all reactors in a cluster.	--	INLET secondary_air 2
	Keyword Usage	Optional keyword. If no streams are defined, the program will assume there is a single inlet for the first reactor in series or that the system is a single closed reactor (if FLRT, SCCM and TAU are not defined).
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Non-reactive Gas Mixer Partially Stirred Reactor (PaSR) Perfectly Stirred Reactor (PSR) Plasma PSR Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	This keyword can not be changed for a restart or continuation run.
INLT Inlet Property	Temperature of the specific phase in the inlet stream.
	Parameters	Optional/Reqd.	Units	Examples
	inlet stream name	Required	--	INLT C1_Inlet1 Gas 300.0 1.0
	phase name	Required	--	INLT C1_Inlet1 urea 300.0
	temperature of the specific phase	Required	K	INLT C1_Inlet1 urea 300.0
	Keyword Usage	Optional keyword. By default the inlet emperature is 300 K.
	Reactor Models	Multiphase PSR Reactor
INLTPRO Inlet Property	Temperature profile specified as a function of time of the specific phae in the inlet stream.
	Parameters	Optional/Reqd.	Units	Examples
	inlet stream name	Required	--	INLTPRO C1_Inlet1 Gas 0.0 300.0
	phase name	Required	--	INLTPRO C1_Inlet1 urea 0.0 300.0
	time value	Required	sec	INLTPRO C1_Inlet1 urea 0.0 300.0
	temperature of the specific phase	Required	K	INLTPRO C1_Inlet1 Gas 0.0 300.0
	Keyword Usage	Optional keyword. By default the inlet temperature is 300 K.
	Reactor Models	Multiphase PSR Reactor
INTM Reactor Property	The estimated peak mole fractions values for "intermediate" species. One of these INTM inputs should appear for each intermediate species desired. It is usually better to estimate values somewhat higher than those that are actually present in the flame. For example, INTM HO2 0.001 gives an estimate fraction of 0.001 for the intermediate HO2. Any given species can participate simultaneously as a reactant, intermediate, or product.
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Required	--	INTM HO20.001
	Estimated fraction	Required	mole fraction	INTM HO2 0.001
	Keyword Usage	Optional keyword. By default, the estimated fraction is set to 0 unless the user has set a minimum threshold to a non-zero value on the Reactor panel (see XIMN to set a non-zero threshold value).
	Reactor Models	Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	See Starting Estimates of the Chemkin Theory Manual for more information.
IONE Reactor Property	Specified energy loss to ions in the sheath for each ion lost at a specified material. The energy that the ions gain in the sheath is specified in electron Volts. For example, "IONE material1 30" would result in an ion energy gain of 30 eV as it crossed the sheath near the material material1. This energy gain for the ions results in a reduced effective power deposition to the electrons (unless ELSH is also specified), as described in Electron Energy Equation for Plasma Systems of the Chemkin Theory Manual .
	Parameters	Optional/Reqd.	Units	Examples
	Material name	Optional If there is no material name than the specified energy loss applies to all materials.	--	IONE material1 30 1
	Specified energy loss	Required	eV	IONE 30
	Reactor number (PSR clusters only)	Optional If no number is given, values are assumed to apply to all reactors in a cluster.	--	IONE material1 30 1
	Keyword Usage	Optional keyword. By default, the ion energy is determined by the ELSH keyword.
	Reactor Models	Closed Plasma Reactor Plasma Plug Flow Reactor Plasma PSR
IPSR XMLI	Use this keyword to specify which PSR to use for the initialization ( XMLI), when more than one PSR is stored on the XML Solution File that is used for initialization (i.e. on XMLdata.zip).
	Parameters	Optional/Reqd.	Units	Examples
	PSR number	Required	--	IPSR 2
	Keyword Usage	Optional keyword. By default, the last PSR saved in the XML Solution File is used.
	Reactor Models	Chemical and Phase Equilibrium Calculations Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Honeycomb Reactor IC HCCI Engine Mechanism Analyzer Non-reactive Gas Mixer Normal Incident Shock Normal Reflected Shock Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor SI Engine Zonal Simulator Stagnation Flow CVD Reactor
IRET Solver	Number of time steps to be taken in Twopnt’s pseudo time stepping algorithm before increasing the time step.
	Parameters	Optional/Reqd.	Units	Examples
	Number of time steps	Required	--	IRET 200
	Keyword Usage	Optional keyword. By default, the number of times steps is set to 25 or 50 depending on the Reactor Model (See Notes below).
	Reactor Models	Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Plasma PSR Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	Default value is 25 for PSRs and 50 for all other reactors listed above.
ISHK Problem Type	Inclusion of this keyword designates an incident shock problem without boundary layer correction.
	Keyword Usage	Required keyword. Either ISHK or ISKB must be included to indicate a Normal Incident Shock problem type. See also RSHK.
	Reactor Models	Normal Incident Shock
ISKB Problem Type	Inclusion of this keyword designates an incident shock problem with boundary layer correction.
	Keyword Usage	Required keyword. Either ISHK or ISKB must be included to indicate a Normal Incident Shock problem type. See also RSHK.
	Reactor Models	Normal Incident Shock
ISTP Solver	Specifies the number of initial pseudo time steps that are taken by the steady-state TWOPNT solver, prior to attempting a Newton iteration. Normally, the Newton iteration will be attempted first, with time steps invoked only if the Newton iteration fails. Nevertheless, there may be circumstances where initial time stepping is desirable. The time step size is specified with the TIM1 or TIM2 keyword. The ISTP keyword only applies to the first grid network, not the subsequently refined ones. If need to find a steady state solution via pure time integration, please refer to the TRAN option.
	Parameters	Optional/Reqd.	Units	Examples
	Number of initial time steps	Required	--	ISTP 100
	Keyword Usage	Optional keyword. By default, the number of initial time steps is set to 0.
	Reactor Models	Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
JJRG Restart	On continuations or restarts, the number of mesh points can be reduced. Twopnt itself does not remove grid points. Therefore, on a sequence of continuation problems the number of grid points can grow because the region where they are needed may change. JJRG thus provides a capability to remove grid points. The old solution is adaptively interpolated onto a new grid of JJRG points. When JJRG is added, its effect is carried over to the subsequent continuations, if any. Often this is not desired. To prevent its operation, JJRG can be set to a high value, such as the maximum number of grid-points. The reduction of grid points then does not happen since JJRG does not add grid-points.
	Parameters	Optional/Reqd.	Units	Examples
	Number of mesh points	Required	--	JJRG 40
	Keyword Usage	Optional keyword. By default, the number of grid points will be the same as in the previous solution.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
KLIM Output	Calculate the ignition delay as the time when the fraction of the specified species reaches its maximum value. Only applicable when you are solving the energy equation with transient solver.
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Required	--	KLIM OH
	Keyword Usage	Optional keyword. See also TIFP .
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Honeycomb Monolith Reactor IC HCCI Engine Perfectly Stirred Reactor (PSR) Plasma PSR Plasma Plug Flow Reactor Plug Flow Reactor SI Engine Zonal Simulator
KMASS Reactor Property	Mass transfer coefficient used to calculate rate of mass exchange between two phases involving gas-liquid or liquid-liquid. This optional keyword follows the line with `VLE` inputs. A separate `KMASS` is specified for the product phase and the reactant phase. The Model parameter specifies which mass transfer model to use. Parameters and units vary depending on specification of model.
	Parameters	Optional/Reqd.	Units	Examples
	Material name (reactant or product)	Required	--	KMASS/ o2(l) CONDL 1.0e-4 0.01/ KMASS/ o2 CONK 1.0e-3/
	Model	Required The model is specified by using one of these Model parameter keywords as the first parameter. `CONK`: Constant value of mass transfer coefficient. `CONDL`: Use two-film theory with (i) constant diffusivity and (ii) length scale. `CONDT`: Use penetration theory with (i) constant diffusivity and (ii) time scale.	mass transfer coefficient: cm/s diffusivity: cm²/s film thickness: cm contact time: s	KMASS/ o2(l) CONDL 1.0e-4 0.01/ KMASS/ o2 CONK 1.0e-3/
	Model parameters	Required For `CONK`, the mass transfer coefficient for that phase is specified by one value. Units are cm/s. For two-film and penetration theories, diffusivity is the first parameter with units of cm²/s. The last parameter is either film thickness (in cm) or contact time (in s).	K	KMASS/ o2(l) CONDL 1.0e-4 0.01/ KMASS/ o2 CONK 1.0e-3/
	Keyword Usage	Optional keyword. By default, the heat loss from the reactor will be zero. See also QLOS and QPRO.
	Reactor Models	Multiphase Reactor
KNMN Reactor Property	The minimum Knudsen number, above which the wall slip-velocity model will be used.
	Parameters	Optional/Reqd.	Units	Examples
	Minimum Knudsen number	Required	--	KNMN 10
	Keyword Usage	Optional keyword. It is relevant only when the slip velocity model is used. See also SLIP .
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor
KOUT Output	List of species names whose mass fractions will be printed to the diagnostic output file for Premixed or Opposed-flow Flames or to the history.plt file for PaSRs. A maximum number of 5 species can be included on a single line.
	Parameters	Optional/Reqd.	Units	Examples
	List of species names	Required	--	KOUT H2 O2 H2O H OH
	Keyword Usage	Optional keyword. By default, none of the species fractions are printed.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR) Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation
LGDT Solver	Controls the time interval for data to be written to the XML Solution File (for example, XMLdata.zip) using a logarithmic time scale.
	Parameters	Optional/Reqd.	Units	Examples
	Logarithmic time-step	Required	ALOG10(sec)	LGDT 1.0
	Keyword Usage	Optional keyword. If neither DTSV nor LGDT are set, then the time step used is ending time minus the beginning time, divided by 100.
	Reactor Models	Normal Incident Shock Normal Reflected Shock
LINE Reactor Property	An indicator that a linear profile is used for the initial gas species distribution along the reactor center line. For Opposed-flow Flames, the mole fractions vary linearly from one inlet to the other, with inlet values forming the end points. For transient CVD Reactors, the mole fractions vary linearly from the inlet values, specified by keyword REAC, to the INIT value at the surface.
	Keyword Usage	Optional keyword. By default, a plateau profile is used for Opposed-flow Flames ( PLAT). For transient CVD Reactors, the default initial gas species profiles are assumed axially uniform with mole fractions specified by INIT ; the keyword is ignored for steady-state CVD Reactor simulations.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
LMLM Reactor Property/Model	Minimum amount of liquid mass to activate the vaporization model.
	Parameters	Optional/Reqd.	Units	Examples
	Minimum total liquid mass	Required	g	LMLM 1.0E-7
	Keyword Usage	Optional keyword. Default is 1.0E-8 g.
	Reactor Models	Direct Injection Diesel Engine Simulator
LODR Reactor Property	Piston offset to crank radius ratio.
	Parameters	Optional/Reqd.	Units	Examples
	Ratio of piston offset to crank radius.	Required	None	LODR 0.1
	Keyword Usage	Optional keyword. Default = 0.0.
	Reactor Models	IC HCCI Engine Multi-zone HCCI Engine SI Engine Zonal Simulator
	Notes	The absolute value of LODR must be less than the value of LOLR minus 1.0: \|LODR\| < (LOLR - 1).
LOLR Reactor Property	Ratio of the length of the engine connecting rod to the crank radius.
	Parameters	Optional/Reqd.	Units	Examples
	Connection rod to crank radius ratio	Required	--	LOLR 5.
	Keyword Usage	Optional keyword. By default, this ratio is 33.3.
	Reactor Models	IC HCCI Engine SI Engine Zonal Simulator
LPRT Output	Printing control LPRT turns on extensive printing that provides information on rates of progress of individual surface reactions. This can be informative in understanding the surface reaction behavior.
	Keyword Usage	Optional keyword. By default, there is no extended printing of surface rate information.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
LSCL Reactor Property	Sets the length scale (cm) for the calculation of gas and surface Damkohler numbers.
	Parameters	Optional/Reqd.	Units	Examples
	Length scale	Required	cm	LSCL 3.
	Keyword Usage	Optional keyword. By default, the length scale is 1 cm.
	Reactor Models	Mechanism Analyzer
LUMPTO Reactor Property	This is an optional approach to species mass conservation closure. In this case, the selected species is assumed to be a diluent and its fraction is set to one minus the sum of all others
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Required	--	LUMPTO AR
	Keyword Usage	Optional keyword.
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor
MAJ Reactor Property	Sets the "Major Species". This is only used to calculate an effective diffusion coefficient when non-dimensionalizing the reaction rate constants.
	Parameters	Optional/Reqd.	Units	Examples
	Species name	Optional	--	MAJ CH4
	Species number	Optional	--	MAJ 1
	Keyword Usage	Optional keyword. The default is to use the gas species with the second largest mole fraction (from the XBTH input) in the bath-gas composition. If the gas-phase bath-gas composition is not specified, the default is to use the second species in the mechanism.
	Reactor Models	Mechanism Analyzer
MASSFRAC Reactor Property	Mass fraction of a bulk phase in the reactor. This specifies the overall composition of the reactor in terms of different bulk phases including gas, liquid, and solid.
	Parameters	Optional/Reqd.	Units	Examples
	Mass fraction of a bulk phase within the reactoR	Required		MASSFRAC Gas 0.6 MASSFRAC JjetFuel 0.4
	Keyword Usage	This keyword is used to specify the composition of the entire reactor. Bulk phase name follows the keyword. "Gas" indicates the gas phase. The composition is normalized to 1 at the start of simulation.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MASSTRAN_CEOF Reactor Property	User-specified mass transfer coefficient for the bulk phase. The same value applies to all phase exchange reactions given by the VLE keyword.
	Parameters	Optional/Reqd.	Units	Examples
	Use specified mass transfer coefficient for the bulk phase	Optional	--	MASSTRAN_CEOF jetFuel 1
	Keyword Usage	This keyword indicates that the mass transfer coefficient value is provided as input. Bulk phase name and value follow the keyword. .
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MASSTRAN_MECHANISM Reactor Property	Use the mass transfer coefficient from the kinetics input file..
	Parameters	Optional/Reqd.	Units	Examples
	Phase name	Required	--	MASSTRAN_MECHANISM GAS
	Keyword Usage	This keyword indicates that the mass transfer coefficient value is provided as input. Bulk phase name and value follow the keyword. .
	Reactor Models	Closed Multiphase Reactor Multiphase PSR Reactor Multiphase PSR
MASSTRAN_LEN Reactor Property	Length scale when two-film theory is used to calculate mass transfer coefficient.
	Parameters	Optional/Reqd.	Units	Examples
	Length scale for the given bulk phase	Optional	cm	MASSTRAN_LEN Gas 0.01
	Keyword Usage	his keyword indicates use of the mass transfer coefficient from the kinetics input file. Bulk name must follow the keyword. The same method must be used specified for both the phases involved in the mass transfer process. "Gas" indicates the gas phase.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MASSTRAN_TAU Reactor Property	Time scale when two-film theory is used to calculate mass transfer coefficient.
	Parameters	Optional/Reqd.	Units	Examples
	Time scale for the given bulk phase	Optional	cm	MASSTRAN_TAU Gas 0.01
	Keyword Usage	This keyword is used when penetration theory is used to calculate mass transfer coefficient between gas-liquid and liquid-liquid bulk phases. Phase name follows the keyword. "Gas" indicates the gas phase.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MAXIT Solver	Controls the maximum number of iterations the integrator solver can take per step to solve the transient problem. The default is 4 and you should increase this value to give the integrator greater chance to solve your problem if it is very hard to solve (stiff or very nonlinear or discontinuous) or if the run fails with a "nonlinear solver failed to converge repeatedly" message.
	Parameters	Optional/Reqd.	Units	Examples
	Iteration number	Required	--	MAXIT 10
	Keyword Usage	Optional keyword.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Partially Stirred Reactor Closed Plasma Reactor Closed Multiphase Reactor Cylindrical Shear Flow Reactor Honeycomb Reactor IC HCCI Engine Multi-Zone HCCI Engine Simulator Partially Stirred Reactor (PaSR) Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma Plug Flow Reactor Plasma PSR Multiphase PSR Plug Flow Reactor Rotating Disk CVD Reactor SI Engine Zonal Simulator Stagnation Flow CVD Reactor
MAXTIME Solver	The maximum number times the steady state solver TWOPNT will use its pseudo-time stepping algorithm. You may need to increase this value for very stiff problems to allow TWOPNT to find a solution by letting it switch between steady state searching and time stepping more than 100 times.
	Parameters	Optional/Reqd.	Units	Examples
	Maximum steady state iterations	Optional	--	MAXTIME 200
	Keyword Usage	Optional keyword. By default, the maximum number of time stepping operations is 100.
	Reactor Models	Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	SSMAXITER must be >=1.
MCUT Reactor Property	Minimum number of particles required to "switch on" the surface rate calculations (coagulation and surface reaction). The default value is 1 [particles/cm³ ].
	Parameters	Optional/Reqd.	Units	Examples
	Material name	Required	--	MCUT C(B) 100
	Cutoff number density	Required	particles/cm³	MCUT C(B) 100
	Keyword Usage	Optional keyword.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Honeycomb Monolith Reactor IC HCCI Engine Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Plasma Plug Flow Reactor Plug Flow Reactor SI Engine Zonal Simulator
MIX Reactor Property	Use a mixture-average model for calculating the transport coefficients and diffusion fluxes.
	Keyword Usage	Optional keyword. By default, mixture-averaged transport is used.
	Reactor Models	Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Planar Shear Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
MIX Reactor Property	Flag indicating a mixing-only problem, where chemistry will be ignored.
	Keyword Usage	Optional keyword. This is the default. See also CHEM and EQUI.
	Reactor Models	Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR)
MIXFRACBIAS_FUEL Reactor Property	Bias factor for the grid on the fuel side, that is, between the mixture fraction equal to its stoichiometric mixture fraction and 1. A value greater than unity should be given and it means more grid points near the stoichiometric mixture fraction.
	Parameters	Optional/Reqd.	Units	Examples
	Bias factor for grid	Required for corresponding grid choice.	--	MIXFRACBIAS_FUEL 1.2
	Keyword Usage	Required keyword.
	Reactor Models	Diffusion Flamelet Generator
MIXFRACBIAS_OXID Reactor Property	Bias factor for the grid on the oxidizer side, that is, between the mixture fraction equal to its stoichiometric mixture fraction and 0. A value greater than unity should be given and it means more grid points near the stoichiometric mixture fraction.
	Parameters	Optional/Reqd.	Units	Examples
	Bias factor for grid	Required for corresponding grid choice.	--	MIXFRACBIAS_OXID 1.2
	Keyword Usage	Required keyword.
	Reactor Models	Diffusion Flamelet Generator
MIXT Reactor Property	The characteristic time of the mixing process in the reactor.
	Parameters	Optional/Reqd.	Units	Examples
	Characteristic time	Required	sec	MIXT 1.0E-3
	Reactor Models	Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR)
MLMT Solver	Specifies the minimum value of gas mass in the zones. By default, the minimum zone mass is set to 10^-6 g.
	Parameters	Optional/Reqd.	Units	Examples
	Value of the b parameter	Optional	--	MLMT 1.0E-5
	Keyword Usage	Optional keyword.
	Reactor Models	SI Engine Zonal Simulator
MMASS MMASS	The reactor wall temperature will be obtained by solving energy conservation equation for the reactor wall. It uses the thermal mass of the reactor wall and the heat transfer coefficient between the inner wall surface and the gas mixture inside the reactor. MMASS specifies the thermal mass of the reactor wall.
	Parameters	Optional/Reqd.	Units	Examples
	Material name	Optional. If no material is specified, the same value will be used for all materials.	--	MMASS material1 500
	Thermal mass	Required	cal/K	MMASS 500
	Reactor number (PSR clusters only)	Optional. If no number is given, the keyword is assumed to apply to all reactors in a cluster.	--	MMASS material1.500 1
	Keyword Usage	Optional keyword. This keyword must be used with GMHTC . For Plug Flow Reactors the unit of thermal mass is cal/(cm-K).
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Honeycomb Monolith Reactor IC HCCI Engine Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Plasma PSR Plasma Plug Flow Reactor Plug Flow Reactor SI Engine Zonal Simulator
MOLFLRT Inlet Property	Molar flow rate of the specific phase in the inlet stream.
	Parameters	Optional/Reqd.	Units	Examples
	inlet stream name	Required	--	MOLFLRT C1_Inlet1 Gas 0.233
	phase name	Required	--	MOFLRT C1_Inlet1 urea 0.0
	molar flow rate of the specific phase	Required	mole/sec	MOLFLRT C1_Inlet1 urea 0.0
	Keyword Usage	Optional keyword. By default the inlet flow rate is zero.
	Reactor Models	Multiphase PSR Reactor
MOLFLRTPRO Inlet Property	Molar flow rate profile specified as a function of time of the specific phae in the inlet stream.
	Parameters	Optional/Reqd.	Units	Examples
	inlet stream name	Required	--	MOLFLRTPRO C1_Inlet1 Gas 0.0 0.233
	phase name	Required	--	MOLFLRTPRO C1_Inlet1 urea 0.0 0.0
	time value	Required	--	MOLFLRTPRO C1_Inlet1 urea 0.0 0.0
	molar flow rate of the specific phase	Required	mole/sec	MOLFLRTPRO C1_Inlet1 Gas 0.0 0.233
	Keyword Usage	Optional keyword. By default the inlet flow rate is zero.
	Reactor Models	Multiphase PSR Reactor Multiphase PSR
MOLEFRAC Reactor Property	Mole fraction of a bulk phase in the reactor. This specifies the overall composition of the reactor in terms of different bulk phases including gas, liquid, and solid.
	Parameters	Optional/Reqd.	Units	Examples
	Mole fraction of a bulk phase within the reactor	Required		MOLEFRAC Gas 0.6 MOLEFRAC jetFuel 0.4
	Keyword Usage	Required for multiphase systems. Two bulk phase names must follow the keyword indicating the bulks in contact. "Gas" indicates the gas phase. Default value of 0 is used for combination of bulks for which the area is not specified.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MOMEN Reactor Property	Turn on or off solution of the momentum equation for a plug-flow simulation.
	Parameters	Optional/Reqd.	Units	Examples
	String "ON" or "OFF" to toggle the momentum equation	Required	--	MOMEN ON MOMEN OFF
	Keyword Usage	Optional keyword. By default, the momentum equation is solved (ON).
	Reactor Models	Honeycomb Reactor Plasma Plug Flow Reactor Plug Flow Reactor
MORD Solver	Maximum order of integration used by the transient solver.
	Parameters	Optional/Reqd.	Units	Examples
	Maximum order of integration	Required	--	MORD 3
	Keyword Usage	Optional keyword. By default, the maximum order of integration is 5.
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
MQAFR Reactor Property	The external heat transfer (heat loss) area fraction of each zone.
	Parameters	Optional/Reqd.	Units	Examples
	Area fraction	Required	--	MQAFR 0.15 4
	Zone number	Required	--	MQAFR 0.15 4
	Keyword Usage	Optional keyword.
	Reactor Models	Multi-Zone HCCI Engine Simulator
MSFX Reactor Property	Use a new discretization scheme for convective flux terms. In some cases, the original discretization scheme might not conserve species fluxes across the flame zone. With this new scheme, species mass fluxes are always conserved. Since accurate mass fluxes require fine resolution of species profiles, this new scheme in general incurs more grid points and longer run time than the original scheme does. The differences between major species solutions obtained by these two schemes are subtle.
	Keyword Usage	Optional keyword. By default, the original discretization scheme is used.
	Reactor Models	Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation
MTDIFF_REFSPEC Reactor Property	Reference species for calculating molecular diffusivity for a liquid phase.
	Parameters	Optional/Reqd.	Units	Examples
	Reference species for diffusivity calculation	Optional	--	MTDIFF_REFSPEC fetFuel nc12h26(l)
	Keyword Usage	This keyword is used to specify reference liquid species for calculation of diffusivity. It is used for liquid-liquid and gas-liquid systems. The bulk phase name and species name follows the keyword.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MTDIFF_SE Reactor Property	Using Stokes-Einstein method for calculation of bulk phase diffusivity. It is used for mass transfer between gas-liquid and liquid-liquid phases.
	Parameters	Optional/Reqd.	Units	Examples
	Method for liquid bulk diffusivity calculation	Optional	--	MTDIFF_SE jetFuel
	Keyword Usage	This keyword is used to specify the Stokes-Einstein method for calculation of diffusivity. The bulk phase name follows the keyword .
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MTDIFF_TRANINP Reactor Property	Using Wilke-Chang method for calculation of bulk phase diffusivity. It is used for mass transfer between gas-liquid and liquid-liquid phases.
	Parameters	Optional/Reqd.	Units	Examples
	Method for gas phase diffusivity calculation	Optional	--	MTDIFF_TRANINP Gas
	Keyword Usage	This keyword is used to specify the use of transport data for calculation of gas diffusivitY.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MTDIFF_USER Reactor Property	User specified diffusivity for the bulk phase.
	Parameters	Optional/Reqd.	Units	Examples
	Use specified diffusivity for the bulk phase	Required	--	MTDIFF_USER jetFuel 0.005
	Keyword Usage	This keyword indicates that diffusivity value is provided as input. Bulk phase name and value follow the keyword.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MTDIFF_WC Reactor Property	Using Wilke-Chang method for calculation of bulk phase diffusivity. It is used for mass transfer between gas-liquid and liquid-liquid phases.
	Parameters	Optional/Reqd.	Units	Examples
	Method for liquid bulk diffusivity calculation	Optional	--	MTDIFF_WC jetFuel
	Keyword Usage	This keyword is used to specify Wilke-Chang method for calculation of diffusivity. Bulk phase name follows the keyword.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MTMODEL_FILM Reactor Property	For using two-film theory for estimation of mass transfer coefficient between gas-liquid and liquid-liquid phases.
	Parameters	Optional/Reqd.	Units	Examples
	Model for estimation of mass transfer coefficient between phases	Optional		MTMODEL_FILM catalyst Gas 50.0
	Keyword Usage	This keyword indicates use of the two-film theory for estimation of mass transfer coefficient. Bulk name must follow the keyword. The same method must be used specified for both the phases involved in the mass transfer process. "Gas" indicates the gas phase.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MTMODEL_PENET Reactor Property	For using penetration theory for estimation of mass transfer coefficient between gas-liquid and liquid-liquid phases.
	Parameters	Optional/Reqd.	Units	Examples
	Model for estimation of mass transfer coefficient between phases	Optional		MTMODEL_PENET Gas
	Keyword Usage	This keyword indicates use of the two-film theory for estimation of mass transfer coefficient. Bulk name must follow the keyword. The same method must be used specified for both the phases involved in the mass transfer process. "Gas" indicates the gas phase.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR
MTMODEL_USER Reactor Property	Use user-specified mass transfer coefficient.
	Parameters	Optional/Reqd.	Units	Examples
	Phase name	Required	--	MTMODEL_USERGAS
	Keyword Usage	This keyword indicates use of user-specified mass transfer coefficient. Bulk name must follow the keyword. The same method must be used specified for both the phases involved in the mass transfer process. "Gas" indicates the gas phase.
	Reactor Models	Closed Multiphase Reactor Multiphase PSR Reactor
MULT Reactor Property	Use full multicomponent model for the transport coefficients and diffusion fluxes. See also MIX.
	Keyword Usage	Optional keyword. By default, mixture-averaged transport is used.
	Reactor Models	Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Planar Shear Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
MVFAC Reactor Property/Model	Artificial scaling factor to modifiy the vaporization rates.
	Parameters	Optional/Reqd.	Units	Examples
	Scaling factor	Required	--	MVFAC 0.9
	Keyword Usage	Optional keyword. Default is 1.0.
	Reactor Models	Direct Injection Diesel Engine Simulator
MXITS Reactor Property/Model	The maximum number of iterations allowed to solve for the droplet surface temperature. This parameter is associated with the "Solve for Surface T" option of the vaporization model.
	Parameters	Optional/Reqd.	Units	Examples
	Number of iterations	Required	--	MXITS 100
	Keyword Usage	Optional keyword. Default is 50.
	Reactor Models	Direct Injection Diesel Engine Simulator
MZMAS Reactor Property	Specifies zone mass fractions. MZM will compute the exact zone volumes at the beginning of the simulation. Use either VOL or MZMAS to set up the initial zone volumes: An error will be issued if both keywords are used in the same input file.
	Parameters	Optional/Reqd.	Units	Examples
	zone mass fraction	Required		MZMAS 0.2 7
	zone number	Required		MZMAS 0.2 7
	Keyword Usage	Optional keyword.
	Reactor Models	Multi-Zone HCCI Engine Simulator
NADAP Solver	Turns off the saving of adaptive points (see ADAP, which is the default). NADAP is provided to turn off adaptive points during a con tin uta ti on run if they have already been turned on with ADAP.
	Keyword Usage	Optional keyword. By default, ADAP is the default in the Ansys Chemkin user interface and NADAP is the default for the command line.
	Reactor Models	Closed Plasma Reactor Closed Homogeneous Reactor Honeycomb Reactor IC HCCI Engine Model Multi-Zone HCCI Engine Simulator Plasma Plug Flow Reactor Multiphase PSR Plug Flow Reactor SI Engine Zonal Simulator
NADP Reactor Property	Number of mesh points that Twopnt can add at one time during each grid refinement.
	Parameters	Optional/Reqd.	Units	Examples
	Number of mesh points	Required	--	NADP 2
	Keyword Usage	Optional keyword. By default, no maximum is set for the number of points that can be added at once by the Twopnt solver.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	This keyword can not be changed on a continuation or restart run.
NCANG Reactor Property	Run the simulation for 180 degrees of crank angle (0.5 revolution). If the "starting crank angle" (DEG0) is set to 180 degrees, the simulation will stop at crank angle = 360 (=180+180) degrees (that is, top dead center). Use one of TIME , NREV , or NCANG to set the simulation time. The last keyword (of the three) in the input file takes effect.
	Parameters	Optional/Reqd.	Units	Examples
	number_of_crank_angles	Required	degrees	NCANG 180
	Keyword Usage	Optional keyword.
	Reactor Models	IC HCCI Engine SI Engine Zonal Simulator
NCFIT Reactor Property	Optional number of time points used to determine the slope when used in conjunction with keyword CTOL.
	Parameters	Optional/Reqd.	Units	Examples
	Number of time points	Required	--	NCFIT 100
	Keyword Usage	Optional keyword. NCFIT is only used in conjunction with CTOL.
		Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR)
	Notes	Default value is 100.
NDPR Output or Solver	Frequency of output printing during time integration, given as the number of time steps.
	Parameters	Optional/Reqd.	Units	Examples
	Print frequency	Required	--	NDPR 50
	Keyword Usage	Optional keyword. By default, the print frequency is at every 1 time step.
	Reactor Models	Closed Partially Stirred Reactor (PaSR) Diffusion or Premixed Opposed-flow Flame Partially Stirred Reactor (PaSR)
NEWRUN Reactor Property	Inclusion of this keyword causes Ansys Chemkin to expect keywords for another problem to follow the END keyword. The following problem does not use the solution of the previous problem as its initial guess. This capability is quite different to that provided by CNTN . The solutions resulting from `NEWRUN` keywords are written sequentially to one XML Solution File.
	Keyword Usage	Optional keyword. By default, no new run is expected.
	Reactor Models	Chemical and Phase Equilibrium Calculations Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Honeycomb Monolith Reactor IC HCCI Engine Mechanism Analyzer Non-reactive Gas Mixer Normal Incident Shock Normal Reflected Shock Partially Stirred Reactor Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Plasma Plug Flow Reactor Plug Flow Reactor Rotating Disk CVD Reactor Using Transient Solver SI Engine Zonal Simulator Stagnation Flow CVD Reactor Using Transient Solver
NINTGSTEPS Reactor Property	The number of internal steps that the solver can take. When the integration time is too long and/or the system of equations is too stiff, the solver may take many internal time steps. This control acts as a check to avoid long, infinite, or hung processes. The simulator may take a corrective action (such as trying a few more steps or declare failure and/or provide diagnostic information).
	Parameters	Optional/Reqd.	Units	Examples
	Maximum value of SSDR	Optional	--	NINTGSTEPS 10000
	Keyword Usage	Optional keyword. The default value for the Diffusion Flamelet Generator is 5000.
	Reactor Models	Diffusion Flamelet Generator
NJAC Solver	For the steady-state Twopnt solver, specifies the maximum number of Newton steps that can be taken in solving the steady state problem before a new Jacobian is evaluated. If NJAC=1, then a full Newton method will result.
	Parameters	Optional/Reqd.	Units	Examples
	Retirement age	Required	--	NJAC 20
	Keyword Usage	Optional keyword. By default, the retirement age is set at 20.
	Reactor Models	Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
NMOM Reactor Property	Number of moments used in the simulation for tracking particle size distribution. MINMO(=3) ≤ NMOM ≤ MAXMO(=6). If NMOM = 6, then 6 moments of the size distribution function are solved, from the 0^th moment to the 5^th moment.
	Parameters	Optional/Reqd.	Units	Examples
	Number of moments	Required	--	NMOM 6
	Keyword Usage	Optional keyword. Default is the MINMO value.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Honeycomb Monolith Reactor IC HCCI Engine Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Plasma Plug Flow Reactor Plug Flow Reactor SI Engine Zonal Simulator
NO_SDOUTPUT_WRITE Output	Do not write output data to a standard (ascii) print-out file.
	Keyword Usage	Optional keyword. By default, solution data will be written to an ascii output file.
	Reactor Models	All
NO_XMLOUTPUT_WRITE Output	Do not write output data to XML file. Note that the ANSYS CHEMKIN post-processor needs solution data in XML format.
	Keyword Usage	Optional keyword. By default, solution data will be written to XML file.
	Reactor Models	All
NNEG Solver	Flag instructing transient solver to try to constrain all components of the solution vector to be non-negative. This is usually unnecessary, but it may help to use this keyword if negative solution components appear to be causing problems in convergence.
	Keyword Usage	Optional keyword. By default, the solution is not constrained and is not usually necessary.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Partially Stirred Reactor (PaSR) Closed Plasma Reactor Honeycomb Reactor IC HCCI Engine Non-reactive Gas Mixer Partially Stirred Reactor (PaSR) Perfectly Stirred Reactor (PSR) Plasma PSR Plasma Plug Flow Reactor Multiphase PSR Plug Flow Reactor SI Engine Zonal Simulator
	Notes	NNEG can be added to but cannot be removed from a continuation run.
NOAGG Reactor Property	Turns off particle aggregation effect. Particle aggregation is included by default in the Particle Tracking module.
	Parameters	Optional/Reqd.	Units	Examples
	Material name	Required	--	NOAGG SOOT
	Keyword Usage	Optional keyword.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Diffusion or Premixed Opposed-flow Flame IC HCCI Engine Multi-Zone HCCI Engine Simulator Perfectly Stirred Reactor (PSR) Plasma PSR Premixed Laminar Burner-stabilized Flame
NOCG Reactor Property	Exclude coagulation of particles.
	Keyword Usage	Optional keyword.
	Reactor Models	Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Honeycomb Monolith Reactor IC HCCI Engine Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma PSR Plasma Plug Flow Reactor Plug Flow Reactor SI Engine Zonal Simulator
NOCH Reactor Property	This keyword specifies that the rates of all gas-phase reactions will be set to zero, regardless of the values specified in the Gas-phase Kinetics input.
	Keyword Usage	Optional keyword. By default, gas chemistry is turned on. See also CHEM.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
NOFT Solver or Reactor Property	For steady-state cases, when this keyword is specified and an energy equation is being solved, the intermediate solution at a fixed temperature will be skipped. In this case, solution to the energy and species equations will be attempted simultaneously from the user-specified initial guess.
	Keyword Usage	Optional keyword. By default, the fixed temperature solution is obtained before adding the energy equation.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Plasma PSR Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	See also, ENRG and ENGE keywords.
NOJC Solver	Flag indicating the non-stiff Adams method (no Jacobian) of the DVODE solver is used to integrate the equations.
	Keyword Usage	Optional keyword. By default, the DASPK solver will be used.
	Reactor Models	Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR)
NONE Output	Turns default output off for all of Surftherm ’s tables. One can use this keyword in combination with another keyword below, to turn on output from only a few features. This keyword will also turn off all previously specified output from keywords given before it.
	Keyword Usage	Optional keyword. By default, the ALL output will be printed.
	Reactor Models	Mechanism Analyzer
NONR Reactor Property	This keyword specifies that the non-reacting problem will not be solved as the first stage in the solution of the full problem.
	Keyword Usage	Optional keyword. By default, the non-reacting problem is solved first.
	Reactor Models	Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
NOTP Reactor Property	Exclude thermophoresis of particles.
	Parameters	Optional/Reqd.	Units	Examples
	Material name	Required	--	NOTP SOOT
	Keyword Usage	Optional keyword. By default, thermophoresis of particles is excluded.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Opposed-flow Flame Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation
NOTP Solver	Do not solve for the initial gas-phase and surface concentrations at the walls using the Twopnt procedure.
	Keyword Usage	Optional keyword. By default, the initial Twopnt procedure is solved.
	Reactor Models	Cylindrical Shear Flow Reactor Planar Shear Flow Reactor
NPAR Reactor Property	The number of statistical events (particles) used by the Monte Carlo process to form the stochastic ensemble.
	Parameters	Optional/Reqd.	Units	Examples
	Number of particles	Required	--	NPAR 1000
	Keyword Usage	Required keyword.
	Reactor Models	Closed Partially Stirred Reactor (PaSR) Partially Stirred Reactor (PaSR)
NP_FUEL Reactor Property	Number of points on the fuel side, that is, between the mixture fraction equal to its stoichiometric mixture fraction and 1.
	Parameters	Optional/Reqd.	Units	Examples
	Number of grid points	Required for corresponding grid choice	--	NP_FUEL 11
	Keyword Usage	Required keyword.
	Reactor Models	Diffusion Flamelet Generator
NP_OXID Reactor Property	Number of points on the oxidizer side, that is, between the mixture fraction equal to its stoichiometric mixture fraction and 0.
	Parameters	Optional/Reqd.	Units	Examples
	Number of grid points	Required for corresponding grid choice	--	NP_OXID 11
	Keyword Usage	Required keyword.
	Reactor Models	Diffusion Flamelet Generator
NPIN Reactor Property	The minimum number of event particles in the reactor whose properties will be replaced by those of the inlet mixture per time step.
	Parameters	Optional/Reqd.	Units	Examples
	Number of particles	Required	--	NPIN 5
	Keyword Usage	Optional keyword. By default, the minimum number of the event particles is 2.
	Reactor Models	Partially Stirred Reactor (PaSR)
NPSR Reactor Property	Number of perfectly stirred reactors (PSRs) or zones in a reactor cluster.
	Parameters	Optional/Reqd.	Units	Examples
	Number of reactors or zones	Required	--	NPSR 5
	Keyword Usage	Optional keyword. By default, the number of PSRs is set to 1.
		Non-reactive Gas Mixer Perfectly Stirred Reactor (PSR) Plasma PSR
NPTS Reactor Property	The number of initial mesh points. The inclusion of NPTS will generate an equi-spaced mesh of NPTS points across the domain, in the axial direction for Flames and CVD Reactors, and in the cross-flow direction for Shear Flow Reactors. The user can also specify an initial non-uniform mesh using the keyword GRID, in which case the NPTS input is not needed.
	Parameters	Optional/Reqd.	Units	Examples
	Number of mesh points	Required	--	NPTS 50
	Keyword Usage	Optional keyword. By default, the number of initial mesh points is set to 6.
	Reactor Models	Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Planar Shear Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
NREV Reactor Property	The number of revolutions of the crank used to determine the end time of the simulation. Fractional values are acceptable.
	Parameters	Optional/Reqd.	Units	Examples
	Number of revolutions	Required	--	NREV 1
	Keyword Usage	Optional keyword. Either NREV or TIME must be specified.
	Reactor Models	IC HCCI Engine SI Engine Zonal Simulator
	Notes	On a restart, the number of crank revolutions will be determined from the value of TIME.
NSOL XMLI	Use this keyword to specify which solution to use for the initialization ( XMLI) or restart ( RSTR), when more than one solution is stored on the XML Solution File that is used for the restart or initialization (for example, on XMLdata.zip).
	Parameters	Optional/Reqd.	Units	Examples
	Solution used	Required	--	NSOL 3
	Keyword Usage	Optional keyword. By default, the last solution saved in the XML Solution File.
	Reactor Models	Chemical and Phase Equilibrium Calculations Closed Homogeneous Batch Reactor Closed Plasma Reactor Cylindrical Shear Flow Reactor Diffusion or Premixed Opposed-flow Flame Honeycomb Reactor IC HCCI Engine Mechanism Analyzer Non-reactive Gas Mixer Normal Incident Shock Normal Reflected Shock Perfectly Stirred Reactor (PSR) Planar Shear Flow Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor SI Engine Zonal Simulator Stagnation Flow CVD Reactor
NSTEPS_HIGH Reactor Property	Number of steps to be taken to reach the specified maximum value of SSDR (SSDR_max). The simulator somputes the new SSDR to be taken on a subsequent step as SSDR used in previous step + fixedStepSize where the fixedStepSize = (SSDR_max - SSDR_Nominal)/NSTEP_High. For example, if the specified nominal and maximum values are 1 and 21, respectively, then 5 steps will yield the constant size to be 4 and result in the sequence of SSDR values as {1, 5, 9, 13, 17, 21}. Continuations to the maximum value can be turned off by setting this input to 0.
	Parameters	Optional/Reqd.	Units	Examples
	Number of steps to maximum SSDR	Required	--	NSTEPS_HIGH 5
	Keyword Usage	Required keyword.
	Reactor Models	Diffusion Flamelet Generator
NSTEPS_LOW Reactor Property	Number of steps to be taken to reach the specified minimum value of SSDR. The simulator computes the new SSDR to be used on a subsequent step as a constantFactor * SSDR_Used_in_previous step. That is, NSTEP_LOW* log(constantFactor) = log(SSDR_min/SSDR_nominal). For example, if the specified nominal and minimum values are 1 and 0.001, respectively, then 3 steps will yield the constant factor to be 0.1 and result in the sequence of SSDR values as {1, 0.1, 0.01, 0.001}. Continuations to the minimum value can be turned off by setting this input to 0.
	Parameters	Optional/Reqd.	Units	Examples
	Number of steps to maximum SSDR	Required	--	NSTEPS_HIGH 5
	Keyword Usage	Required keyword.
	Reactor Models	Diffusion Flamelet Generator
NTOT Reactor Property	Maximum number of grid points allowed during mesh adaptation.
	Parameters	Optional/Reqd.	Units	Examples
	Number of grid points	Required	--	NTOT 200
	Keyword Usage	Optional keyword. The default maximum number of grid points is 100 for: Rotating Disk CVD Reactor, Stagnation Flow CVD Reactor; 250 for Diffusion or Premixed Opposed-flow Flame, Premixed Laminar Burner-stabilized Flame, Premixed Laminar Flame-speed Calculation.
	Reactor Models	Diffusion or Premixed Opposed-flow Flame Premixed Laminar Burner-stabilized Flame Premixed Laminar Flame-speed Calculation Rotating Disk CVD Reactor Stagnation Flow CVD Reactor
	Notes	This keyword can not be changed on a restart or continuation run. In previous versions, NMAX keyword was used.
NZCDC Inlet Property	Discharge coefficient of the injector.
	Parameters	Optional/Reqd.	Units	Examples
	Injector name	Required	--	NZCDC modelX 0.68
	Discharge coefficient	Required	--	NZCDC modelX 0.68
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
NZDIA Inlet Property	Diameter of the nozzle hole of the injector.
	Parameters	Optional/Reqd.	Units	Examples
	Injector name	Required	--	NZDIA modelX 0.037
	Diameter	Required	--	NZDIA modelX 0.037
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
NZHOL Inlet Property	Number of nozzle holes in the injector.
	Parameters	Optional/Reqd.	Units	Examples
	Injector name	Required	--	NZHOL injector1 8
	Number of holes	Required	--	NZHOL injector1 8
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
NZINJ Inlet Property	Number of injections from the injector.
	Parameters	Optional/Reqd.	Units	Examples
	Injector name	Required	--	NZINJ stock1 2
	Number of injections	Required	--	NZINJ stock1 2
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
NZLDR Inlet Property	Nozzle hole length to diameter ratio of the injector.
	Parameters	Optional/Reqd.	Units	Examples
	Injector name	Required	--	NZLDR modelX 4.0
	Length to diameter ratio	Required	--	NZLDR modelX 4.0
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
NZONE Reactor Property	Specifies the number of zones to be used in the multi-zone simulation. This keyword MUST be used with the ICEN keyword or an error will be issued. The default value is 1 (= single zone model). The multi-zone model will be turned on when NZONE > 1.
	Parameters	Optional/Reqd.	Units	Examples
	Number of zones	Required	--	NZONE 5
	Keyword Usage	Optional keyword.
	Reactor Models	Multi-Zone HCCI Engine Simulator
NZRDR Inlet Property	Ratio of the radius of the inside rounded corner to the nozzle diameter of the injector.
	Parameters	Optional/Reqd.	Units	Examples
	Injector name	Required	--	NZRDR injector1 0.06
	Corner radius to diameter ratio	Required	--	NZRDR injector1 0.06
	Keyword Usage	Required keyword.
	Reactor Models	Direct Injection Diesel Engine Simulator
NZRWL Inlet Property	The characteristic distance from the nozzle to the cylinder wall or the piston head. When the spray parcel penetration distance is greater than this value, the wall-impingement submodel will be activated. The wall-impingement model will adjust the speed and the average droplet diameter of the spray parcel. The model assumes all liquid mass will rebound back to the cylinder volume.
	Parameters	Optional/Reqd.	Units	Examples
	Injector name	Required	--	NZRWL injector1 6.0
	Nozzle distance	Required	cm	NZRWL injector1 6.0
	Keyword Usage	Optional keyword. Default is 1.0E6.
	Reactor Models	Direct Injection Diesel Engine Simulator
OINL Reactor Property	The inlet-gas spin rate. At the inlet , = OINL.
	Parameters	Optional/Reqd.	Units	Examples
	Inlet-gas spin rate	Required	rpm	OINL 100
	Keyword Usage	Optional keyword. By default, the inlet-gas spin rate is 0.0.
	Reactor Models	Rotating Disk CVD Reactor
OMEG Problem Type and Reactor Property	The disk rotation rate; also specifies the Rotating Disk CVD Reactor model.
	Parameters	Optional/Reqd.	Units	Examples
	Disk rotation rate	Required	rpm	OMEG 1000
	Keyword Usage	Required keyword. See also STAG.
	Reactor Models	Rotating Disk CVD Reactor
OPMV Reactor Property	Specify the conventional opposed-piston movement.
	Keyword Usage	Optional keyword (required to turn on this option).
	Reactor Models	Direct Injection Diesel Engine Simulator IC HCCI Engine Multi-Zone HCCI Engine SI Engine Zonal Simulator
OPOC Reactor Property	Specify the opposed-piston opposed cylinder movement.
	Keyword Usage	Optional keyword (required to turn on this option).
	Reactor Models	Direct Injection Diesel Engine Simulator IC HCCI Engine Multi-Zone HCCI Engine SI Engine Zonal Simulator
OXID Inlet or Reactor Property	Defines the oxidizer mole fraction composition for an inlet stream in an open system, or for the initial conditions in a closed system, when an equivalence ratio is specified ( EQUI). It must be followed by a species name and then the mole fraction. One of these OXID inputs must appear for each oxidizer species, which are used to determine the inlet composition based on an equivalence-ratio calculation ( EQUI). Any given species can participate simultaneously as a fuel, oxidizer, or product. The sum of all the oxidizer mole fractions should equal one. If it does not, a warning message will be printed and the mole fractions will be normalized so the sum does equal one.
	Parameters	Optional/Reqd.	Units	Examples
	Inlet stream name (PSRs only)	Optional If there is no stream name than the oxidizer mole fraction composition applies to the default or all defined streams.	--	OXID mixture1 O2 0.5
	Species name	Required	--	OXID O2 0.5
	Fuel fraction	Required	mole fractions	OXID O2 0.5
	Keyword Usage	Required keyword when EQUI option is used for an inlet stream or for the initial conditions in a reactor.
	Reactor Models	Closed Homogeneous Batch Reactor Honeycomb Reactor IC HCCI Engine Perfectly Stirred Reactor Plasma Plug Flow Reactor Plasma PSR Plug Flow Reactor SI Engine Zonal Simulator
	Notes	The mole fractions are of the oxidizer itself, not for the entire composition. The OXID keywords must be changed as a set, not individually for a restart run. The OXID keywords must be changed as a set, not individually for continuation run.