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Leigh December 9, 2006 09:57

Furnace Combustion wall problem
 
Hello all,

I am modelling a simple 3D furnace geometry in which combustion is taking place. I have a working adiabatic combustion model, and as I next step I have made the model non-adiabatic and assigned a heat flux value to the walls of the furnace. This value was calculated from the calorific value of the fuel and the surface area of the furnace. The value I calculated is around 300Kw/m2. This value is high- as i expected it to be. When I run the model under this heat flux, I get large temperatures around the edges of the walls of the furnce. Can anyone see what is happening and maybe point me in the right direction??

Thanks,

Leigh

RoM December 11, 2006 08:16

Re: Furnace Combustion wall problem
 
Did you get the sign right? +300Kw/m3 means heating the domain while -300kW/m2 is cooling (heat loss). Also from my personal experience i find it troublesome to assign a constant heatflux as a wall bc for a furnace. The results with a constant wall temperature (or even better a temperature profile) as bc are usually better.

RoM

Leigh December 11, 2006 16:01

Re: Furnace Combustion wall problem
 
Hello RoM,

Thanks for your reply and for pointing out my error in the sign of the heat flux value of the wall. (I wondered why it was becoming so high in temperature!). I will try my model with the correct -ve heat flux, and if I still have problems I will try a temperature profile bc.

Cheers, Leigh


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