I am trying to simulate a 2-phase flow. One phase is gas, the other is solid particulates. But the *.fc file failed to be run by the CFX solver. The generated *.fo file keeps telling me fhe following,

####> ERROR. IN DATA FOR PHASE 2 THE MOLECULAR WEIGHT = -1.0000E+00 THIS MUST BE SET BY THE USER AND HAVE A value GREATER THAN 0.0

THE CFX-4 SOLVER HAS BEEN STOPPED BY SUBROUTINE SPEC1

Can anyone please tell me in what part of the *.fc file I am supposed to set the molecular weight for the solid phase? Thanks in advance.

The reason for the error could be an error in your command file. Try to open the command file from within the enviroment, if you have made some simple spelling errors or mismatched in the command language they will be removed.

I did build the command file from within the CFX environment. There is no grammar mistake with it. My question is, besides the PCP database, is there any other way by which I can set the physical parameters (molecular weight, thermal diffusivity) for the solid phase of a multi-phase flow (one phase is gas, the other is solid particulate).

From what I understand, you are running a compressible flow simulation by setting the gas to compressible and solids phase to incompressible. It shouldn't ask you for the molecular weight if the solid is set as incompressible, unless there are reaction in there. You can set the molecular weight of the fluid as follows:

>>PHYSICAL PROPERTIES

>>COMPRESSIBILITY PARAMETERS

PHASE NAME 'GAS'

FULLY COMPRESSIBLE

UNIVERSAL GAS CONSTANT 8.3140E+03

FLUID MOLECULAR WEIGHT 2.8970E+01

REFERENCE PRESSURE 1.0130E+05

>>COMPRESSIBILITY PARAMETERS

PHASE NAME 'SOLID'

INCOMPRESSIBLE

Hope this helps.