MATC enthalpy def for phase change breaks latent heat check

[mzenker]

Hi,

I have now implemented a UDF for the effective heat capacity which just computes a derivative of the specific enthalpy and multiplies that one by density. It seems that indeed this was the route to success - my simulation runs now, I will see what result I get.

@NJank: My conclusions are the same as yours. I also did introduce some debug print statements in HeatSolve.
Normally you should not need a full Fortan development environment to compile ElmerSolver, but as stated in the other thread mentioned above the available compilation instructions didn't work for me. I still hope that sometime soon, the Elmer Windows compilation guru takes the effort to update the compilation instructions. I will be happy to serve as test person...

BTW, I use a UDF calling another one for the heat capacity. In case someone wants to know how to do that, I will update this thread http://www.elmerfem.org/forum/viewtopic.php?f=7&t=2288 in a minute.

Thank you again Peter and NJank for your assistance!

Matthias

[NJank]

Hi,

I have now implemented a UDF for the effective heat capacity which just computes a derivative of the specific enthalpy and multiplies that one by density. It seems that indeed this was the route to success - my simulation runs now, I will see what result I get.

Solid density... liquid density? I usually just specify the enthalpy enthalpy in the first place.

[mzenker]

You are right, the density changes when the phase changes (if you are picky, it depends on temperature no matter what phase we have, let alone CFD simulations with temperature change...). But since for temporal and spatial 2 models, the effective heat capacity should be needed only to get the simulation started, it might be tolerable to use the density at room temperature here.
I have defined the specific enthalpy in another UDF. Since it gets divided by density internally, I should indeed think about making the density depend on temperature.
Of course one could also calculate the volumetric enthalpy including temperature dependent density and specify that one.
I am just beginning to get this phase change thing under control - it's a step by step process...

Matthias