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-   -   VOF with melting of Phase change materials (http://www.cfd-online.com/Forums/fluent/112193-vof-melting-phase-change-materials.html)

 sakil2k3 January 23, 2013 14:05

VOF with melting of Phase change materials

Dear all,
I m modeling a phase change problem with VOF and solidification. The problem description is a biker containing PCM and air. When i simulate the melting is only from the down and wall side. No melting is occurred due to upper air surface. I m uning pressure outlet for upper boundary condition.
can any one help??

 vig January 24, 2013 07:36

Melting would initiate from the points where the temperature is above the melting temperature which could be the case near the walls. Pressure outlet boundary has the input for backflow temperature, it means melting of the top layer depends on temperature being initialized in the air phase.

 thermal energy March 15, 2014 07:53

Hello dear friends,

I try to simulate melting process using VOF model. Pcm is solid phase initialy. Upper part of the solid there is air. They do not mix eachother. the rectangular box is %85 full with solid pcm, %15 air
Natural convection is active. My primary phase air, secondary phase is pcm (phase change material). I have some questions to be sure about my model.

Initial condition of Wholesystem temperature is 293K, but air temp is 300K. how to set air temp ? from materials -referance temperature?

For cell zone condition, all cell zone (air, pcm, fin ) show mixture. Also for example, if I change pcm to phase2, all of cell zone change to phase 2 . is it ok or not

Only for secondary phase (pcm), I patch within fluent by adapt-region-mark then patch. Ok? Value of volume fraction should be 1 or 0 while patching?? I am confused. Initialy pcm is solid. the rectangular box is %85 full with solid pcm. %15 air

For initial values phase-2 volume fraction is 0 or 0.85. Ok?

I did some iteration for a short time to check model. For results, in graphics-countors I can not see total temperature for phase 1 and 2 only entalphy values I see for phase1 and 2.

Also countors of solidification/melting it shows only mixture. Mixture shows what?

Any interaction should I use like surface tension etc.

Thanks for your help. ı am really in stuck. good work friends.