16.2.9. Variables Relevant for Multiphase Calculations

The following table contains a list of variables (with both long and short variable names) that can be used when working with multiphase calculations. For an explanation of the column headings, see List of Field Variables.

Note:  Variables with names shown in bold text are not output to CFD-Post. However, some of these variables can be output to CFD-Post by selecting them from Extra Output Variables List on the Results tab of the Solver > Output Control details view of CFX-Pre.

Long Variable Name

Short Variable Name

Units

Availability

Definition

Interfacial Area Density

area density

[m^-1]

3

C

Interface area per unit volume for Eulerian multiphase fluid pairs.

Interphase Mass Transfer Rate

ipmt rate

[ ]

3

C

Interface mass transfer rate for Eulerian multiphase fluid pairs.

Mean Particle Diameter

mean particle diameter

[m]

3

A, C, M

Mean particle diameter for an Eulerian dispersed phase (including Polydispersed Fluids).

Volume Fraction

vf

[ ]

1

A, C, M, P, R, TS

For details, see Volume Fraction in the CFX-Solver Modeling Guide.

Conservative Volume Fraction

vfc

[ ]

2

A, C, M, R, TS

For details, see Volume Fraction in the CFX-Solver Modeling Guide.

Drift Velocity

drift velocity

[ ]

2

C, M, R, TS

Velocity of an algebraic slip component relative to the mixture.

Slip Reynolds Number

slip Re

[ ]

3

C

Reynolds number for Eulerian multiphase fluid pairs.

Slip Velocity

slipvel

[ ]

1

C, M, R, TS

Velocity of an algebraic slip component relative to the continuous component.

Surface Tension Coefficient

surface tension coefficient

[N m^-1]

2

C

Surface tension coefficient between fluids in a fluid pair.

Unclipped Interfacial Area Density

unclipped area density

[m^-1]

3

C

Similar to area density, but values are not clipped to be non-zero.

Superficial Velocity

volflx

[m s^-1]

1

A, C, M, R, TS

The Fluid.Volume Fraction multiplied by the Fluid.Velocity.

Interphase Lift Force

MPFlift

[Kg m^-2 s^-1]

3

Force on the continuous phase due to MPF lift

Interphase Drag Force

MPFdrag

[Kg m^-2 s^-1]

3

Force on the continuous phase due to MPF drag

Interphase Turbulent Dispersion Force

MPFtdisp

[Kg m^-2 s^-1]

3

Force on the continuous phase due to MPF turbulent dispersion

Interphase Wall Lubrication Force

MPFlubr

[Kg m^-2 s^-1]

3

Force on the continuous phase due to MPF wall lubrication

Lubrication Force Direction

wlubdir

[]

3

Direction in which the wall lubrication force acts on the dispersed phase