[Benfa]

Hi,

I am modelling a cavity that will be filled up by steam. It is a transient simulation with the goal to obtain the cavitys wall temperature over time. The other interesting physic will be the condensing of the steam on the initialy cold walls. therefore I will use the "wall condensation model". But there is something that makes me nervouse. The condensating steam is tracked by a trasnport euqation and another gas (for example) air is uses as constraint to fill up the near wall cells where the steam will vanish. But if I fill up my closed cavity the steam will push out the initial air and therefore there will be no air with increasing time. when the cavity is filled with steam the condensing water should be substituted by steam. but it is not possible to define a steam material as constraint because it can not condense. Am I missundesratnding anything or is the model not suitable for my application?

Thanks