[TimRB]

Hello,
I'm attempting to run a simple condensation on a cold wall case. I start with a mixture of steam and CO2 (I have tried with various mass fractions of steam from 0.01 to 0.99) and a film with is 1e-4m thick on the cold wall. My case is laminar and the condensate is pure water (although defined as a multi-component liquid with only water). Saturation pressure is defined using the Antoine equation (I have checked the coefficients with the original document referenced in the Star-CCM+ manual) and I have run a case with temperature above and below boiling temperature. I have gone through all the documentation I can find including on the Siemens support centre and tired all sorts of tricks they suggest (e.g. changing the heat of formation to 0 in the steam and the difference between the two in the water film). Nothing seems to stop the explosion in temperature and pressure values as soon as condensation occurs. Does anyone have any suggestions as to what might be causing this? Or a case I could compare to try and figure out what I am doing wrong?