[CFD_Michele]

Originally Posted by vinerm

You might have used temperature boundary condition, however, you need to observe the heat being transferred to the liquid. If the heat transferred is not enough for the evaporation, then it will not evaporate. Also ensure that the material properties are given correctly, especially, enthalpies for liquid and vapor. It is their difference that is important and not their actual values.

Expansion of vapor is important since it requires that much space to be available. If the system is open, then it can flow out. However, if the space is closed, then vapor must be modeled as ideal gas.

Material properties are not easy to find. First because I defined a LPG material, so as to avoid using propane and n-butane separately Secondly because Fluent gives the vapour properties but not the liquid one (that are not easy to find on the web). Do you have some suggestion about finding LPG properties?

My system is open, it consists of an inlet pipe, a radiator and an outlet pipe. I used to extend pipes in order to avoid issues at the boundaries, in this case both pipes are extended 40 times the diameter.

[vinerm]

I am sorry, but I have never worked with LPG, so, I don't have those properties. I suppose it would be easier to find properties of its constituents and then calculate based on mass fractions.

[Mazze[ITA]]

Hi guys,

I am having the same issues. Did you find a solution for the mass imbalance? My impression is that, for some reason, the mass transfer rate is unbalanced towards the condensation rather than the evaporation.