Lee Model, evaporation and heat transfer
 

Hi all!


I am trying to setup evaporation with icoReactingMultiphaseInterFoam using the Lee model.


I have been reading about it, and I am not sure I totally understand how this model takes into account the heat transfer due to the phase change.


Indeed, in the documentation of Openfoam, only the mass transfer is discussed. Does someone know more about this? I saw in a lot of papers that the Lee model was used to model heat transfer systems with good accuracy.


Thanks for your help!

Hello,

It is my understanding that the Lee model accounts for mass transfer between phases during a phase change induced by heat, and as you mentioned this mass transfer is discussed in OpenFOAM documentation. The heat transfer is addressed in TEqn file.

Best,

Hi, thanks for the pointer!


From what I could understand, the heat transfer is accounted for by multiplying the latent heat by the mass transfer occuring through phase change, so we should be good :)




I am now trying to set up my simulation, and another question appears:


Is it possible to have condensation happening from a multiComponentMixture to a pureMixture, from gas to liquid? Specifically, to have a mass transfer between one of the species of the multiComponent gas to its pure liquid phase.


What I have been trying, without much success:



Since having a negative C supposedly activates condensation, I figure it is the only thing to change (no change in the order of the names etc).


Maybe someone has had more experience with this kind of setup? Thanks for any tip!

I tried to reproduce the approach you mentioned, but it was unsuccessful. Was it successful for you?

Hey,


I kept my modifications but with a lower C (C = -100) to force the condensation. I will keep this thread updated :)

After several tries, I still can't figure out how to make condensation happen, no matter how I change phaseProperties or the thermophysical files, the enthalpies involved and the temperatures.


Until someone can provide a working example of condensation from one species of a gas mixture to a pure mixture, I guess I am stuck :D

AFAIK Lee is only implemented for >>from pureMixture to pureMixture<<.



The errror message that I receive using different combinations results in >>Unknown interface composition Type, valid types are: (ESI-OFv2106)
From that aspect, I would choose another combination from that list for your problem or you extend the capabilities..

Hi!


Okay that's strange, because evaporation happens from the liquid pure mixture to one of the species in my gax mixture. The setup looks like this:



I am using openfoam v2206.

Ah I havent seen the second entry. Then you have probably wrong settings. Please share your configuration files.


From what I see, I would recommend to you changing the entry (liq to gas) to (gas to liq). I dont know for sure, since im not working with ESI OF, but they are working with structured/ordered Phase Pairs!

I would try out both of the following snippets:
or without the evaporation


And playing around with the C value..

Hey :)


Thanks for your reply!


I already had tried to swap the order from "liquid to gas" to "gas to liquid" as you suggest but OpenFoam throws an error:


So it seems no mass transfer can occur from a multicomponent mixture ( but it can from a pure mixture).


But I think my original configuration is true from a mathematical point of view: in the OF doc, about the Lee model, when C < 0, the mass flux is negative which means that the liquid receives mass (as opposed to C > 0, and the mass flux is positive).


In the meantime, I tried to initialize my liquid phase to a really small amount in my domain (1e-6) to see if it could 'trigger' the condensation and it looks like it does! More fluid is generated in the cold zone where it should, but I can't yet say if it is due to numerical errors or something else... But the Lee model should not need this, the condensation should be happening spontaneously right?


Anyway, there is still a lot to figure out :D

Just a suggestion about Unknown the error


In the file InterfaceCompositionModels.C, the various combinations that are permitted to be used while working with various mass transfer models are defined. I've modified this file previously for a different project, and added some new combinations, compiled it as a new user library, and used it in my thermal phase change solver. So,*I am aware that new combinations can be added, however I am unsure whether or not this will be effective in your particular case. I think it's worth a shot. :)

Hey, thanks for the reply!


I will have to check this out, I am not comfortable enough yet to tinker with these files but that might be a good starting point!


I will keep this thread updated as I figure it out :)

Hey all!


Quick update about the condensation setup:


When only the condensation is enabled, it seems to work, but when evaporation is too, the first of the two subdictionaries in phaseProperties takes over and forcefully "disable" the other (considering that the two subdictionaries are identical except for the sign of C).


I have not yet found a way to overcome this issue, I will keep trying things :)

Hey Aliyah,


I took some time to look more into what you suggest, but I am not sure how to proceed. I modified a solver once (just to test things out) but I am not sure how to tackle this thing.


So far I tried to copy the whole folder phasesSystem containing the massTransferModels folder, and in InterfaceCompositionModels.C I added a block for the Lee model from a multicomponent mixture to pure phase. After modifiying files and options I tried to compile without much success (could have bet on it :rolleyes:).


Is this the way to proceed? Thanks for any tip!

Hello, that seems right, if possible write the error you get while compiling the new library here?

Hey!


Sure, thanks for looking into it :D


So my modified block in InterfaceCompositionModels.C looks like this:


And the error I get is visible in the attached pic. I didn't modify the other files except in the Make directory. Thanks for the help!


I have to add that I read other posts about implementing mass transfer from a multicomponent mixture to a pure phase, and it seems rather difficult (modifiying the MULES algorithm etc to account for the volume change, quantities...)

There is a comma at the end of constRhoHThermoPhysics which should be removed. *I'm not sure that's the only problem, but let's try fixing it and then see what happens.

Nice catch! It does compile now, but once I run icoReactingMultiphaseInterFoam I get a new error (see picture).


Here are my files and options, thanks again for your help:

options:

So the procedure is after compiling the new library, you should compile the new solver with the new library. For compiling the new icoReacting solver you need to enter the address of the new library in the Make/option and EXE_INC part. Also you should mention the name of the new library in the LIB_LIBS part. Do not forget to add -L$(FOAM_USER_LIBBIN) \ and then adding the name of your library

I do not know that you have done all the previous steps. Right now I guess you have not mentioned the name of the new library or writing L$(FOAM_USER_LIBBIN). This stuff is probably the issue, but it's just a guess.

Hey :)


Thanks for the helpful answer, I tried to compile a new solver myIcoReactingMultiphaseInterFoam but during wmake I get a new error (see attached picture). I fear there is much more to do to get it working :D




I changed the files for the lib according to your indications (it compiles properly)


Here is my options for the new solver :



As always thanks for your time!