DO radiation model
 

Hi Users! I'm trying to check Fluent's DO model against experimental data to gain confidence in it, but making little headway.

The problem is a cylinder 0.2m diameter and 0.2m height with nitrogen and CO2 coming in one end and out a small radial gap at the other end. I'm using the Descrete Ordinates model, cos it's the only one for both optically thin domains and soot particles (which i will need later). absorbtion coefficient from the WSGGM.

I'm comparing that against Hottel's calculations for gas emissivity, but Fluent gives ten times more heat flux than Hottel. Any recommendations welcome.

Hugo.

Re: DO radiation model
 

Dear Hugo,

I would not use/compare the WSGGM model in Fluent 6.1/2/3 against published data unless you understand the differences in Fluent implementation and those publications.

You are better off, checking with a even simpler problem. For example, 1-D radiation transfer between parallel plates. Check Michael Modest's book for some examples.

keep us posted on your findings,

Opaque.

Re: DO radiation model
 

Like yous plan, Stan! I was comparing Fluent against Hottel's experimental correlation of CO2 and H2O emmisivity, which I guessed was relatively straight forward, but I'll follow your advice...

I'd been giving the infinite plates some thought... a 2D rectangular domain: top and bottom are the two plates, sides are periodic boudaries, making it effectively infinite. No need for the medium to be moving (though that would give convergance problems...). Sound ok?

H.