I've got a problem trying to run a 2 phase flow problem in CFX 4.3. I have set both the Volume Fractions in the domain to the values I want, and I've checked by writing a text file that these are set correctly, but as soon it begins to solve both the Volume Fractions in the whole domain become 0.5, except at the inlet, where they are as I specified.

Does anyone know why this should be the case? Any suggestions will be much appreciated.

Regards

Richard Pemberton

You need to initialize the phase volume fraction field in the domain, otherwise the solver uses a default of (1/nphase) everywhere. You will need to use the user subroutine USRINT to do this. See m01.f provided for CFX-4.x Reference Example 29.