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-   -   How to Model Heat Pipe (http://www.cfd-online.com/Forums/fluent/91905-how-model-heat-pipe.html)

Heat Pipe August 26, 2011 02:16

How to Model Heat Pipe
 
Hi every one,
Recently I got this type of Heat pipe to do simulation for it as a master work
But I faced some problems, one of them how to create a geometry correctly
by Gambit then export to Fluent to solve it??

http://www.iraqup.com/up/20110826/51...Y_28368876.jpg


please any help to start my work

Heat Pipe August 26, 2011 06:18

i'm waiting !!!

Heat Pipe August 27, 2011 02:13

then !! No one has any expert

Heat Pipe August 27, 2011 11:01

3-Days with No Replay,,,
Why Open Forum !!!

Heat Pipe September 18, 2011 03:37

hello
where r the seniors of forum

m2montazari September 18, 2011 14:56

hi,
please explain more about your problem and dont be angry of the forum! it seems that the only thing you want is a cicular pipe mesh. and it seems that you dont need even a 3d model but only an axissymmetry one. so simply a rectangle with good stretch of nodes near the wall is all you need. if I'm wrong with your problem, just explain more...
yours,
mohammad

Heat Pipe September 18, 2011 15:11

Dear Mohammed I'm not angry but as you know if some-body wants help and no one reply ,,, bad feelings isn't ???

Okay I wanna to know the boundary types zones with gambit
and then how to set up the 2-phase flow for vapor and water
by the way 2-phase r not mixture separated

m2montazari September 18, 2011 15:44

hi,
OK.
you dont need to specify anything in gambit about the twophase. if I have understood correctly, there is no external boundary between two phase and liquid and vapor are changing there phase continuously. so just make a rectangle in gambit and in fluent you can mark any cell you want and patch their phase volume fraction to zero or one. check that...
yours,
mohammad

Heat Pipe September 18, 2011 15:51

I know friend 2-phase will define with Fluent but which one the best ( VOF-Eulerian),, I mean boundary condition (interface, velocity inlet and mass inlet) etc,, by the way at the evaporator the water will vaporize and flow through the core(inner space) and at the condensation the vapor will condensate and flow through the wick wall ??

this case more complex because heat and mass transfer within the interface !!!

m2montazari September 19, 2011 02:39

hi,
I think VOF would be better but as fluent cant model vaporization in vof, I think you have no chance but using mixture(as much as I know). you don't need any interface boundary. the walls must be wall and inlet should be massflowinlet or pressure inlet. also if the pipe has infinite length, periodic boundary condition may suit the best to you problem.
be aware of that the evaporation and condensation in fluent is very difficult and I don't have any good suggestion about that. you can cheat that by using cavitation model and setting proper vapor pressure and ... but it is not the a correct procedure.
yours,
mohammad

Heat Pipe September 19, 2011 02:49

Friend,,,
ends of heat pipe connected with end caps so at inlet and outlet at axial and radial is no flow only at interface between water-vapor at evaporator and condenser ,,,, so the mixture mode in not correct choice because water within tube,, vapor within another tube ,,,

its clear now


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