Learning Forum

[Weiqiang Liu]

Hi all,

I am modeling fuel combustion in porous zone with fluent. The temperature is different between porous solid and fluid locally. In other words, the solid and fluid are in non thermal equilibrium state. However, I don't want to use the in-build non thermal equilibrium model of fluent. Instead I want to use dual energy equations to solve fluid and solid temperature separately. 

The general idea is to use a UDS to solve solid temperature in which I can define source term, diffusion coefficient and so on. The energy equation of fluid is solved by fluent automatically. However, I have two confusions before I can start my modeling work.

Firstly, although I use a UDS to solve solid energy equation, fluid still solves energy equation of fluid assuming thermal equilibrium state. In other words, the conduction term, unsteady term of fluid equation still solves in a volume averaged method. I mean should I modify the energy equation of fluid energy equation to make it non-volume averaged?

secondly, I have chemical reactions in fluid domain. Then how to deal with source terms caused by chemical reactions to fluid and solid. My thinking is to assume combustion source term is only added to fluid energy equation by default. And then, fluid and solid exchange heat by user defined source term?

Best regards

Weiqiang

[Weiqiang Liu]

Hi all,

I think I have to modify thermal conduction coefficient of fluid. Because I compared the energy equation of thermal equilibrium and non thermal equilibrium in fluent theory manual. I found it's different regarding to fluid thermal conductivity.

Best regards

Weiqiang