# Numerical modelling of closed loop pulsating heat pipe with compressible flow

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 December 1, 2019, 01:57 Numerical modelling of closed loop pulsating heat pipe with compressible flow #1 New Member   Sabrina Carson Join Date: May 2018 Posts: 15 Rep Power: 5 Dear All, Recently I wrote an article on numerical simulation of closed loop pulsating heat pipe. The solver I used deals with codensation and Evaporation. The fluid was considered to be incompressible. The reviewer rejected the article and argued, "The solver that is utilised here is an incompressible VOF-based solver. In this case how it operated on a closed loop domain without blowing up. How mass is conserved? The application of this solver for the specific application is questionable according to my opinion. The compressibility issue needs to be addressed." Can anyone suggest how can I model compressible condensation and evaporation situation ? Which CFD package can deal with this situation (e.g. ANSYS, COMSOL etc.)? Or how can I make modifications in existing solvers (e.g. in OpenFOAM)?

 December 1, 2019, 12:06 #2 Senior Member   Lucky Tran Join Date: Apr 2011 Location: Orlando, FL USA Posts: 4,438 Rep Power: 53 Indeed there are certain mass conservation issues when running certain scenarios in a closed domain. In short, you can run a constant density steady simulation or a compressible transient simulation. You need to clarify what you mean by "the fluid was considered to be incompressible." The reviewer also needs to clarify what they mean by incompressible. Most solvers nowadays are not true incompressible solvers anyway (they're compressible solvers w/ an equation of state for density and have no problem). You might have "shot yourself in the foot" by even mentioning the word incompressible when it was not needed. No idea what solver you used to comment on the applicability of any solver. Also not sure what compressibility issue is being mentioned.

December 1, 2019, 14:25
#3
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Arjun
Join Date: Mar 2009
Location: Nurenberg, Germany
Posts: 1,044
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Quote:
 Originally Posted by sabrinacarson Dear All, Recently I wrote an article on numerical simulation of closed loop pulsating heat pipe. The solver I used deals with codensation and Evaporation. The fluid was considered to be incompressible. The reviewer rejected the article and argued, "The solver that is utilised here is an incompressible VOF-based solver. In this case how it operated on a closed loop domain without blowing up. How mass is conserved? The application of this solver for the specific application is questionable according to my opinion. The compressibility issue needs to be addressed." Can anyone suggest how can I model compressible condensation and evaporation situation ? Which CFD package can deal with this situation (e.g. ANSYS, COMSOL etc.)? Or how can I make modifications in existing solvers (e.g. in OpenFOAM)?

There exist no multiphase simulation that preserves mass 100 %. I know of none.

 Tags ansys, boiling, condensation, evaporation, openfoam