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-   -   Conjugate heat transfer models (http://www.cfd-online.com/Forums/phoenics/52314-conjugate-heat-transfer-models.html)

Alex January 15, 2009 07:33

Conjugate heat transfer models
 
Dear friends

Need a decsription on how conjugate heat transfer is performed in PHOENICS.

I have done simple one-D simulation for solid only and it work with both boundaries at fixed but at different temperature, and there is constant temperature gradient in the solid. I set the solid with zero heat flux

With similar heat flux setting for the solid, i model the solid with stationary gas, and there is constant but different temeprature gradient on both solid and flud. I switch of the effect of bouyancy in the simulation

The third case is simulation an impinging jet on zero heat flux on the solid ( allow conduction effects only) only temperature gradient exist in the fluid, but not on the solid. Thanks for any advice

Alex January 19, 2009 05:00

More on Conjugate heat transfer models
 
Dear friends

I have also considered the impingment flow by solving separately the flow and energy equation. Using the converged flow solution as the starting conditions for solving the energy equation, there is no appearance on conduction effects in the solid as the heat was set to zero.

Appreciate for advice on the scope of application of conjugate heat transfer incorporated in PHOENICS

thank for the advice


Alex January 20, 2009 05:03

Material properties in conjugate HT model
 
dear friends

I have manage to find the reasons why 'NO' conduction effects in the solid model in solving the conjugate heat transfer. The earlier problems was tested on metals in which no such gradient was 'qualitatively seen'. As I replace the material with low conductivity substances, the results show the existence of conduction effects.

My personnel conclusion is PHOENICS is still the best choice of performing CFD.

thanks guy for the silence, as this put me to the struggle

TQ

Jebe P. Nugas February 8, 2009 09:03

Re: Conjugate heat transfer models
 
Help me to find my assignment about ZERO HEAT TRANSFER...........


Alex February 10, 2009 03:58

Re: Conjugate heat transfer models
 
First we need to define the meaning conjugate heat transfer in the CFD practice(hope other will correct me if I am wrong).

Conjugate heat transfer involve the study of flow convection and conduction heat transfer in solid. The cfd code solve the property of interest (temperature/energy) in solid and fluid.

I set the problem through Virtual Reality.You need to tell PHOENICS that you will solving the energy transport equation.

What I did was setting the total energy of the solid within the fluid (blockage) with 0 Watts .

Yuri Zudin March 4, 2009 10:45

Re: Conjugate heat transfer models
 
Hi! I have wrote the book on this theme

http://www.amazon.com/Theory-Periodi.../dp/3540707239

http://www.amazon.co.uk/Theory-Perio...e=UTF8&s=books

Yuri

Mahe March 16, 2009 09:16

Dear Alex
To solve conjugate heat transfer problem in phoenics, you should :firstly store the prps which is a varible to store the material; secondly, tell phoenics that every regions are what material. In polis, there are detailed description on conjugate heat transfer problem which may be helpful to you

loordhu19 March 27, 2009 05:29

Error in multiple fluid domain
 
Hi CFD members

In my multiple fluid domain conjugate heat transfer analysis, i am getting error as

Error in subroutine FNDVAR :
Error finding variable DENSITY_FL2
GETVAR originally called by subroutine GET_MFLOIP_ZIF

I have given desity for all domains.

Could you please help me to rectify this error ???????

Thanks
Loordhu

PattiMichelle April 6, 2009 15:58

The other thing you have to remember is that it won't solve for conjugate heat transfer if you are solving Enthalpy, rather than Temperature...


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