Q. I have a question regarding the Turbulent Schmidt and Turbulent Prandlt number using the KEpsilon model for a combustion application.
From the Advanced Turbulence model control on the Fluid Domains panel, it appears there is a Turbulence Flux Closure for K and E terms. Does this mean that the Schmidt and Prandtl numbers are applied to the entire set of transport equations or just the turbulence terms. We would like to apply the Schmidt and Prandtl numbers to the entire set of transport equations.
A. The data structures under Turbulence Model/Advanced Model Control are for the corresponding turbulence equations only. Turbulent Schmidt/Prandtl numbers for scalar equations may be specified by CCL as follows:
FLOW:
DOMAIN: <domain name>
FLUID MODELS:
# Enthalpy and all mass fractions share same value (specified under heat transfer model):
HEAT TRANSFER MODEL:
Option = Thermal Energy  Total Energy
TURBULENT FLUX CLOSURE:
Option = Eddy Diffusivity
Turbulent Prandtl Number = 0.9
END
END
# For additional variables (individually for each scalar):
ADDITIONAL VARIABLE: <av name>
Option = Transport Equation
TURBULENT FLUX CLOSURE:
Option= Eddy DiffusivityTurbulent SchmidtNumber = 0.9
END
END
END
END
END
**** Entered By: dsclarke @ 12/16/2005 04:21 PM ****
Q. I have a question regarding the Turbulent Schmidt and Turbulent Prandlt number using the KEpsilon model for a combustion application. From the Advanced Turbulence model control on the Fluid Domains panel, it appears there is a Turbulence Flux Closure for K and E terms. Does this mean that the Schmidt and Prandtl numbers are applied to the entire set of transport equations or just the turbulence terms. We would like to apply the Schmidt and Prandtl numbers to the entire set of transport equations. A. The data structures under Turbulence Model/Advanced Model Control are for the corresponding turbulence equations only. Turbulent Schmidt/Prandtl numbers for scalar equations may be specified by CCL as follows: FLOW: DOMAIN: <domain name> FLUID MODELS: # Enthalpy and all mass fractions share same value (specified under heat transfer model): HEAT TRANSFER MODEL: Option = Thermal Energy  Total Energy TURBULENT FLUX CLOSURE: Option = Eddy Diffusivity Turbulent Prandtl Number = 0.9 END END # For additional variables (individually for each scalar): ADDITIONAL VARIABLE: <av name> Option = Transport Equation TURBULENT FLUX CLOSURE: Option= Eddy DiffusivityTurbulent SchmidtNumber = 0.9 END END END END END **** Entered By: dsclarke @ 12/16/2005 04:21 PM **** 

