Problem about Free Convection between double-Wall
 

Hi..all please help !! the detail of my model are 1. natual convection between the gap of double-wall 2. I set inlet openning as pressure inlet and set outlet openning as pressure outlet 3. double-wall are difference temperature.

I have problem about How to set material type (fluid is air) I try ideal gas, incompress-ideal gas, Boussinesq but not work then I would like to define density upon temperature. Do you have any suggestion ?

If I would like to define density as density=352.2057/(Temerature)

What should I do and Can I use polynomial ?

Thank you for advance help !

The`am

If you don't understand. i am sorry, about poor in English

Re: Problem about Free Convection between double-W
 

hi Why can't work when setting ideal gas, incompress-ideal gas, Boussinesq?you must make sure the operate condition have been setted. If you would like to define density as density=352.2057/(Temerature), 1.you can get the real curve . 2.use the piecewise polynomial approimation to instead of the inverse function. hope these can help you.

Re: Problem about Free Convection between double-W
 

If you tried ideal gas, incompressible ideal gas and Bossinesq and none of them worked, I suspect you may have applied gravity in the wrong vector. Double check you gravity specification.