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Ken Adams January 20, 2007 13:10

How to model natural convection
Hi all,

I'm modeling a heatsink with several heat sources distributed on it. The whole system is exposed to air and cooled by natural convection. But could anyone tell me how to specify the space surrounding the system as air/fluid in Fluent/Gambit and how to set parameters for natural convection?

Thank you,


Suijth January 21, 2007 14:56

Re: How to model natural convection
You can give the heat transfer coeff as a boundary condition to wall, if you have a wall boundary and heat convection is taking place over it.

Else you can model the entire domain with surroundings and fluent will calculate the heat transfer.

Ken Adams January 21, 2007 18:35

Re: How to model natural convection
Thank you, Suijth. But could you explain more on the last sentence?

Sujith January 23, 2007 13:23

Re: How to model natural convection
You have to make two zones in the domain, fluid and solid. At the interface btween the two, fluent will make it a coupled wall boundary condition. Only thermal eqns will be solved in the Solid. Now you can model the natural convection over this wall.

there is one tutorial available at, tutorial 5 , which solves a problem with natural convection. You may need to use bossenisque parameters for good results in natural convection.


Ken Adams January 23, 2007 16:14

Re: How to model natural convection
Thank you very much.

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