22.1. Latin Equation Symbols

The table below shows the conventions used in this document for Latin equation symbols.

Table 22.1: Latin Symbols

Description	Chapter	CGS Units
Pre-exponential factor in sticking coefficient expression	Surface Chemical Rate Expressions	none
Activity of the k th bulk-phase species	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models	none
Standard state specific Helmholtz free energy of the k th species	Thermodynamic Expressions, Surface Chemical Rate Expressions	ergs/g
Coefficients of fits to thermodynamic data	Surface Chemical Rate Expressions	depends on
Mean specific Helmholtz free energy of a mixture	Thermodynamic Expressions	ergs/g
Total surface area of all materials in the reactor	Homogeneous 0-D Reactor Models	cm²
Cross-sectional area of the stream tube encompassing the flame	1-D Premixed Laminar Flames	cm²
Cross-sectional area available for flow downstream of the shock wave	Normal Shock Equations	cm²
Surface Area	Surface Chemical Rate Expressions	cm²
Mean molar Helmholtz free energy of a mixture	Thermodynamic Expressions	ergs/mole
Standard state molar Helmholtz free energy of the k th species	Thermodynamic Expressions	ergs/mole
Pre-exponential factor in the rate constant of the i th reaction	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	depends on reaction
Surface area of the m th material	Homogeneous 0-D Reactor Models	cm²
Temperature exponent in sticking-coefficient expression	Surface Chemical Rate Expressions	none
Concentration of the k th species (gas-phase or bulk-phase)	Homogeneous 0-D Reactor Models	mole/cm³
Concentration of the k th species (surface-phase)	Homogeneous 0-D Reactor Models	mole/cm²
Activation energy in sticking-coefficient expression. By default, Gas-phase Kinetics and Surface Kinetics use activation energies in thermal calories instead of ergs.	Surface Chemical Rate Expressions	cal/mole
Specific heat at constant pressure of gas mixture	Normal Shock Equations, Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	ergs/(g K)
Specific heat capacity at constant pressure of the k th species	Thermodynamic Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Normal Shock Equations , Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	ergs/(g K)
Internal contribution to the mass specific heat of the k th species	Gas-phase Species Transport Properties	ergs/(g K)
Rotational contribution to the mass specific heat of the k th species	Gas-phase Species Transport Properties	ergs/(g K)
Specific heat capacity at constant volume of the k th species	Thermodynamic Expressions	ergs/(g K)
Mean specific heat capacity at constant pressure	Thermodynamic Expressions	ergs/(g K)
Mean specific heat capacity at constant volume	Thermodynamic Expressions	ergs/(g K)
Compression ratio for the IC HCCI engine model	Homogeneous 0-D Reactor Models	none
Ratio defined by shock tube equations.	Normal Shock Equations	none
Molar heat capacity at constant pressure of the k th species	Thermodynamic Expressions	ergs/(mole K)
Turbulent scalar-to-mechanic time scale ratio	Partially Stirred Reactor (PaSR) Model	none
Standard state molar heat capacity at constant pressure of the species	Thermodynamic Expressions, Stagnation-Flow and Rotating-Disk CVD	ergs/(mole K)
Translational contribution to the molar heat capacity of the k th species	Gas-phase Species Transport Properties	ergs/(mole K)
Vibrational contribution to the molar heat capacity of the k th species	Gas-phase Species Transport Properties	ergs/(mole K)
Rotational contribution to the molar heat capacity of the k th species	Gas-phase Species Transport Properties	ergs/(mole K)
Molar heat capacity at constant volume of the k th species	Thermodynamic Expressions	ergs/(mole K)
Modeling constant for the IEM model	Partially Stirred Reactor (PaSR) Model	none
Mean molar heat capacity at constant pressure	Thermodynamic Expressions, Partially Stirred Reactor (PaSR) Model	ergs/(mole K)
Mean molar heat capacity at constant volume	Thermodynamic Expressions	ergs/(mole K)
Chemical creation rate of the k th species	Gas-phase Chemical Rate Expressions	mole/(cm³sec)
Cylinder bore diameter for the IC HCCI engine model	Homogeneous 0-D Reactor Models	cm
Hydraulic diameter (4 times the ratio of the cross-sectional area of the tube to the perimeter of the tube)	Normal Shock Equations	cm
Thermal diffusion coefficient of the k th species	Surface Chemical Rate Expressions, Gas-phase Species Transport Properties , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Opposed-flow and Stagnation Flames , Stagnation-Flow and Rotating-Disk CVD	g/(cm sec)
Ordinary multicomponent diffusion coefficient of the species in species	Surface Chemical Rate Expressions, Gas-phase Species Transport Properties , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames	cm²/sec
Binary diffusion coefficient of species in species	Gas-phase Species Transport Properties, 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	cm²/sec
Mixture-averaged diffusion coefficient of the k th species	Gas-phase Species Transport Properties, Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	cm²/sec
Chemical destruction rate of the k th species	Gas-phase Chemical Rate Expressions	mole/(cm³sec)
Activation energy in the rate constant of the i th reaction. By default, Gas-phase Kinetics and Surface Kinetics uses activation energies in thermal calories instead of ergs.	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	[cal/mole]*
	1-D Premixed Laminar Flames, Stagnation-Flow and Rotating-Disk CVD	ergs/mole
Energy of a positive ionic species	Surface Chemical Rate Expressions	[cal/mole]*
Energy threshold in ion-energy-dependent reactions	Surface Chemical Rate Expressions	[cal/mole]*
Energy threshold in reaction yield expression	Surface Chemical Rate Expressions	[cal/mole]*
Exponential constant in ion-energy-dependent reactions	Surface Chemical Rate Expressions	none
Forward reaction-order specified for the k th species in i th reaction	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	none
Acceleration of gravity	Boundary-layer Channel Flow	cm/sec²
Exponential constant in ion-energy-dependent reactions	Surface Chemical Rate Expressions	none
Standard state specific Gibb’s free energy for the k th species	Thermodynamic Expressions	ergs/g
Mean specific Gibb’s free energy of a mixture	Thermodynamic Expressions	ergs/g
Small number (e.g. 1.E-12)	Gas-phase Species Transport Properties	none
Linear growth rate for the k th bulk species	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , Stagnation-Flow and Rotating-Disk CVD	cm/sec
Standard state molar Gibb’s free energy for the k th species	Thermodynamic Expressions, Surface Chemical Rate Expressions	ergs/mole
Mean molar Gibb’s free energy of a mixture	Thermodynamic Expressions	ergs/mole
Specific enthalpy of the k th species	Thermodynamic Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Normal Shock Equations , Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	ergs/g
Specific enthalpy of the k th species	Partially Stirred Reactor (PaSR) Model	ergs/mole
Heat transfer coefficient	Homogeneous 0-D Reactor Models	ergs/(sec K)
Specific enthalpy of the electron upon creation of the gas-phase	Homogeneous 0-D Reactor Models	ergs/g
Mean specific enthalpy of a mixture	Thermodynamic Expressions, Normal Shock Equations	ergs/g
Multiplicative factor in reaction yield expression	Surface Chemical Rate Expressions	depends on reaction
Enthalpy of formation	Surface Chemical Rate Expressions	ergs/mole
Standard state molar enthalpy of the k th species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	ergs/mole
Molar enthalpy of the k th species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	ergs/mole
Mean molar enthalpy of a mixture	Thermodynamic Expressions	ergs/mole
Total number of reactions	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Homogeneous 0-D Reactor Models , Stagnation-Flow and Rotating-Disk CVD	none
Flux of gas-phase species into the surface	Stagnation-Flow and Rotating-Disk CVD	mole/(cm²sec)
Diffusive mass flux of the k th species	Gas-phase Species Transport Properties	ergs/g
Jacobian matrix	1-D Premixed Laminar Flames	none
Total number of grid points	Stagnation-Flow and Rotating-Disk CVD	none
Boltzmann Constant	Gas-phase Species Transport Properties	ergs/K
Forward rate constant of the i th reaction	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , 1-D Premixed Laminar Flames	depends on reaction
Reverse rate constant of the i th reaction	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	depends on reaction
Total number of species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Homogeneous 0-D Reactor Models , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	none
Total number of bulk species	Surface Chemical Rate Expressions, Boundary-layer Channel Flow , Stagnation-Flow and Rotating-Disk CVD	none
Total number of bulk species on the m th material.	Homogeneous 0-D Reactor Models	none
Index of the first bulk-phase species in the first bulk phase	Stagnation-Flow and Rotating-Disk CVD	none
Index of the first bulk species	Boundary-layer Channel Flow	none
Index of the first bulk-phase species in phase	Surface Chemical Rate Expressions	none
Index of the first bulk-phase species in phase of the m th material	Homogeneous 0-D Reactor Models	none
Index of the last bulk-phase species in the last bulk phase	Stagnation-Flow and Rotating-Disk CVD	none
Index of the last bulk-phase species in phase	Surface Chemical Rate Expressions, Boundary-layer Channel Flow	none
Index of the last bulk-phase species in phase of the m th material.	Homogeneous 0-D Reactor Models	none
Equilibrium constant in concentration units for the i th reaction	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Stagnation-Flow and Rotating-Disk CVD	depends on reaction
Total number of gas-phase species	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , Stagnation-Flow and Rotating-Disk CVD	none
Index of the first gas-phase species	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Stagnation-Flow and Rotating-Disk CVD	none
Index of the last gas-phase species	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Stagnation-Flow and Rotating-Disk CVD	none
Equilibrium constant in pressure units for the i th reaction	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Stagnation-Flow and Rotating-Disk CVD	depends on reaction
Total number of surface species	Surface Chemical Rate Expressions, Boundary-layer Channel Flow , Stagnation-Flow and Rotating-Disk CVD	none
Total number of surface species on the m th material	Homogeneous 0-D Reactor Models	none
Index of the first surface-phase species in the first surface phase	Stagnation-Flow and Rotating-Disk CVD	none
Index of the first surface species in phase	Surface Chemical Rate Expressions, Boundary-layer Channel Flow	none
Index of the first surface species in phase of the m th material	Homogeneous 0-D Reactor Models	none
Index of the last surface-phase species in the last surface phase	Stagnation-Flow and Rotating-Disk CVD	none
Index of the last surface species in phase	Surface Chemical Rate Expressions, Boundary-layer Channel Flow	none
Index of the last surface species in phase of the m th material	Homogeneous 0-D Reactor Models	none
Array containing the number of species in each phase	Surface Chemical Rate Expressions, Stagnation-Flow and Rotating-Disk CVD	none
Array containing the number of species in each phase for material	Homogeneous 0-D Reactor Models	none
Distance between the shock and the contact surface at infinite distance from the diaphragm	Normal Shock Equations	cm
Film-thickness length scale	Homogeneous 0-D Reactor Models	cm
Crank-arm length for the IC HCCI engine model	Homogeneous 0-D Reactor Models	cm
Length of the connecting rod for the IC HCCI engine model	Homogeneous 0-D Reactor Models	cm
Reduced molecular mass for the collision	Gas-phase Species Transport Properties	g
Molecular mass of the k th species	Surface Chemical Rate Expressions, Gas-phase Species Transport Properties	g
Mass flow rate at inlet	Partially Stirred Reactor (PaSR) Model	g/sec
Mass loss rate at the lower boundary	Boundary-layer Channel Flow	g/(cm^(1-α)sec)
Mass flow rate at outlet	Partially Stirred Reactor (PaSR) Model	g/sec
Mass loss rate at the upper boundary	Boundary-layer Channel Flow	g/(cm^(1-α)sec)
Mass flux at the channel inlet	Boundary-layer Channel Flow	g/(cm^(1-α)sec)
Mass flux	Boundary-layer Channel Flow	g/(cm^(1-α)sec)
Mass flow rate	1-D Premixed Laminar Flames	g/sec
Number of materials in the surface reaction mechanism	Homogeneous 0-D Reactor Models	none
Reactor mass	Partially Stirred Reactor (PaSR) Model	g
Molecular weight of the k th species, replaces .	Stagnation-Flow and Rotating-Disk CVD	g/mole
Mean molecular weight of a mixture, replace .	Stagnation-Flow and Rotating-Disk CVD	g/mole
Total molar concentration of a mixture	Gas-phase Chemical Rate Expressions	mole/cm³
Interior unit normal vector. Surface-normal unit vector; points from the gas into the bulk layer	Surface Chemical Rate Expressions	cm
Number of coefficients in polynomial fits to	Thermodynamic Expressions, Surface Chemical Rate Expressions , Stagnation-Flow and Rotating-Disk CVD	none
Total number of event (statistical) particles	Partially Stirred Reactor (PaSR) Model	none
Total number of phases	Surface Chemical Rate Expressions	none
Total number of phases for the m th material	Homogeneous 0-D Reactor Models	none
Avogadro’s number	Surface Chemical Rate Expressions	none
Total number of bulk phases	Surface Chemical Rate Expressions, Stagnation-Flow and Rotating-Disk CVD	none
Number of event (statistical) particles to be effected by convection	Partially Stirred Reactor (PaSR) Model	none
Total number of bulk phases for the m th material	Homogeneous 0-D Reactor Models	none
Index of the first bulk phase	Surface Chemical Rate Expressions, Stagnation-Flow and Rotating-Disk CVD	none
Index of the first bulk phase for the m th material	Homogeneous 0-D Reactor Models	none
Index of the last bulk phase	Surface Chemical Rate Expressions, Stagnation-Flow and Rotating-Disk CVD	none
Index of the last bulk phase for the m th material	Homogeneous 0-D Reactor Models	none
Number of gas phases (always equal to 1)	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models	none
Number of event (statistical) particles to be effected by molecular mixing	Partially Stirred Reactor (PaSR) Model	none
Total number of surface site types (phases)	Surface Chemical Rate Expressions, Boundary-layer Channel Flow , Stagnation-Flow and Rotating-Disk CVD	none
Total number of surface site types (phases)	Homogeneous 0-D Reactor Models	none
Index of first surface phase	Surface Chemical Rate Expressions, Stagnation-Flow and Rotating-Disk CVD	none
Index of first surface phase	Homogeneous 0-D Reactor Models	none
Index of last surface phase	Surface Chemical Rate Expressions, Stagnation-Flow and Rotating-Disk CVD	none
Index of last surface phase	Homogeneous 0-D Reactor Models	none
Nusselt number for heat transfer for the IC HCCI engine model	Homogeneous 0-D Reactor Models	none
Scaled circumferential velocity () at the inlet	Stagnation-Flow and Rotating-Disk CVD	1/sec
Pressure	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Normal Shock Equations , Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	dynes/cm²
Spatially-varying component of pressure in radial momentum equation.	Stagnation-Flow and Rotating-Disk CVD	dynes/cm²
Pressure of one standard atmosphere	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Homogeneous 0-D Reactor Models	dynes/cm²
Probability density function of scalar	Partially Stirred Reactor (PaSR) Model	none
Energy source term for heating of surface	Stagnation-Flow and Rotating-Disk CVD	ergs/(cm²sec)
Prandtl number for the IC HCCI engine model	Homogeneous 0-D Reactor Models	none
Net heat transfer from reactor to ambient	Stagnation-Flow and Rotating-Disk CVD	ergs/sec
Total energy deposited into the gas from a heat source	Stagnation-Flow and Rotating-Disk CVD	ergs/(cm²sec)
Heat flux	Gas-phase Species Transport Properties	ergs/(cm²sec)
Rate of progress of the i th gas-phase reaction.	Stagnation-Flow and Rotating-Disk CVD	mole/(cm³sec)
Rate of progress of the i th reaction.	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	mole/(cm²sec)
Heat loss to the walls for the IC HCCI engine model	Homogeneous 0-D Reactor Models	ergs/sec
Radial coordinate	Stagnation-Flow and Rotating-Disk CVD	cm
Universal gas constant	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Normal Shock Equations , Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	ergs/(mole K)
Universal gas constant, in units consistent with activation energy	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	[cal/(mole K)]*
Reverse reaction-order specified for the k th species in the i th reaction.	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	none
Ratio of over for the IC HCCI engine model	Homogeneous 0-D Reactor Models	none
Reynolds number for the IC HCCI engine model	Homogeneous 0-D Reactor Models	none
Standard state specific entropy of the k th species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	ergs/(g K)
Mean specific entropy of a mixture	Thermodynamic Expressions	ergs/(g K)
Production rate of the k th species from surface reactions	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , Stagnation-Flow and Rotating-Disk CVD	mole/(cm²sec)
Standard state molar entropy of the k th species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions	ergs/(mole K)
Molar entropy of the k th species	Gas-phase Chemical Rate Expressions	ergs/(mole K)
Spatially distributed thermal energy source	Thermodynamic Expressions	ergs/(cm³sec)
Mean molar entropy of a mixture	Thermodynamic Expressions	ergs/(mole K)
Average piston speed for the IC HCCI engine model	Homogeneous 0-D Reactor Models	cm/sec
Time	Surface Chemical Rate Expressions, Normal Shock Equations , Homogeneous 0-D Reactor Models , Partially Stirred Reactor (PaSR) Model , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	sec
Laboratory time	Normal Shock Equations	sec
Gas-particle time	Normal Shock Equations	sec
Temperature	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Normal Shock Equations , Homogeneous 0-D Reactor Models , Partially Stirred Reactor (PaSR) Model , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	K
Reduced temperature for the collision	Gas-phase Species Transport Properties	none
Reduced temperature of the k th species	Gas-phase Species Transport Properties	none
Ambient temperature	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Stagnation-Flow and Rotating-Disk CVD	K
Electron temperature	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models	K
Temperature of the ions.	Homogeneous 0-D Reactor Models	K
Surface temperature	Homogeneous 0-D Reactor Models, Stagnation-Flow and Rotating-Disk CVD	K
Chamber wall temperature for the IC HCCI engine model	Homogeneous 0-D Reactor Models	K
Temperature to which the surface radiates	Stagnation-Flow and Rotating-Disk CVD	K
Axial velocity of fluid mixture ( direction)	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	cm/sec
Gas velocity in shock-fixed coordinates	Normal Shock Equations	cm/sec
Exponential constant in reaction yield expression	Surface Chemical Rate Expressions	none
Specific internal energy of the k th species	Thermodynamic Expressions, Surface Chemical Rate Expressions	ergs/g
Mean specific internal energy of a mixture	Thermodynamic Expressions	ergs/g
Gas velocity in laboratory-fixed coordinates	Normal Shock Equations	cm/sec
Molar internal energy of the k th species	Thermodynamic Expressions	ergs/mole
Reflected shock velocity	Normal Shock Equations	cm/sec
Incident shock velocity	Normal Shock Equations	cm/sec
Standard state internal energy of the k th species	Thermodynamic Expressions	ergs/mole
Mean molar internal energy of a mixture	Thermodynamic Expressions	ergs/mole
Fluid velocity in direction	Boundary-layer Channel Flow	cm/sec
Gas velocity (vector)	Gas-phase Species Transport Properties, Normal Shock Equations	cm/sec
Volume	Surface Chemical Rate Expressions, Homogeneous 0-D Reactor Models , Partially Stirred Reactor (PaSR) Model , Stagnation-Flow and Rotating-Disk CVD	cm³
Scaled radial velocity	Stagnation-Flow and Rotating-Disk CVD	1/sec
Clearance volume in an engine cylinder for the engine model	Homogeneous 0-D Reactor Models	cm³
Correction velocity	1-D Premixed Laminar Flames, Stagnation-Flow and Rotating-Disk CVD	cm/sec
Diffusion velocity of the k th species	Surface Chemical Rate Expressions, Gas-phase Species Transport Properties , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	cm/sec
Diffusion velocity of the k th species in the division	Boundary-layer Channel Flow	cm/sec
Ordinary diffusion velocity of the k th species	Gas-phase Species Transport Properties, 1-D Premixed Laminar Flames	cm/sec
Ratio used shock tube equations	Normal Shock Equations	none
Scaled circumferential velocity	Stagnation-Flow and Rotating-Disk CVD	1/sec
Half-width of the distribution of energy source term	Stagnation-Flow and Rotating-Disk CVD	cm
Mean molecular weight of a mixture	Thermodynamic Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames	g/mole
Molecular weight of the k th species	Thermodynamic Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Normal Shock Equations , Homogeneous 0-D Reactor Models , Partially Stirred Reactor (PaSR) Model , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	g/mole
Thermal diffusion velocity of the k th species	Gas-phase Species Transport Properties, 1-D Premixed Laminar Flames	cm/sec
Molecular weight of the positive ionic species in a Bohm-type reaction	Surface Chemical Rate Expressions	g/mole
Spatial coordinate along principal flow direction	Surface Chemical Rate Expressions, Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	cm
Position of the center of the energy source term	Stagnation-Flow and Rotating-Disk CVD	cm
Array of surface species mole fractions	Surface Chemical Rate Expressions	none
Mole fraction of the k th species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Determining Chemical Equilibria , Normal Shock Equations , Homogeneous 0-D Reactor Models , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	none
Molar concentration of the k th species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Stagnation-Flow and Rotating-Disk CVD	mole/cm³
Cross-stream coordinate	Boundary-layer Channel Flow	cm
Maximum channel dimension	Boundary-layer Channel Flow	cm
Mass fraction of the k th species	Gas-phase Chemical Rate Expressions, Surface Chemical Rate Expressions , Gas-phase Species Transport Properties , Normal Shock Equations , Homogeneous 0-D Reactor Models , Partially Stirred Reactor (PaSR) Model , Boundary-layer Channel Flow , 1-D Premixed Laminar Flames , Stagnation-Flow and Rotating-Disk CVD	none
Distance	Normal Shock Equations	cm
Array of surface species site fractions	Surface Chemical Rate Expressions	none
Ratio used in Shock Reactor.	Normal Shock Equations	none
Site fraction of the k th species at a site	Stagnation-Flow and Rotating-Disk CVD	none
Site fraction of the k th species on surface phase	Surface Chemical Rate Expressions, Boundary-layer Channel Flow	none
Site fraction of the k th species on site of the m th material	Homogeneous 0-D Reactor Models	none

Note: The energy CGS units that are noted by an asterisk (*) depend upon user input at the REACTIONS line or in the UNITS auxiliary keyword for chemistry input files. The default unit is thermal calories.