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A.S. May 25, 2005 02:06

Gaseous Combustion Help
 
Hi,

I am doing a simple problem on gaseous combustion. The fuel is propane, which enters from 1 inlet and air entering from other inlet is taken as 21% O2 and 79% N2. I have set-up adiabatic PPDF model as guided in tutorial. Now the problem I am facing is that I am not getting proper results. I have checked model again and again with-out any clue where it is going wrong. My doubt is about 'solution method' in Analysis control for 'addiational scalars'. The default comes 'internal' for all scalars except 'mixture fraction' and 'variance', default scalar set-up by StarCd. My question is that what would be the 'solution method' for propane, o2 and n2. Similarly for CO, CO2 and H2O, products of reaction. This is a very simple case I am trying. Please help.

Thanks

A.S.

matej May 26, 2005 04:40

Re: Gaseous Combustion Help
 
Hi,

The tutorial works, and if you follow its settings, or take the defaults when setting the PPDF schema, it should be OK. Is your PPDF schema realy set? Have you tried to plot the profiles of the variables, temp, density?

you do not provide enough information for any reasonable help. tell us more what it means not good results. it does not combust? is the temerature low, high, solution diverges? what happens?

matej

A.S. May 26, 2005 06:58

Re: Gaseous Combustion Help
 
The solution is osscilating. My question is what should be method for transport in additional for propane(fuel), oxygen and nitrogen(air composition) and similarly for product of combsution like CO, CO2 etc. I am not modelling NOX at present. Actually am working on news gaseous combustor design.

Thanks

A.S.

yjl May 31, 2005 10:32

Re: Gaseous Combustion Help
 
Only the mixtue fraction and its variance should be solved by transport equations and all other scalars are solved by 'Internal' method. Also you need to run double precision.

A.S. May 31, 2005 11:00

Re: Gaseous Combustion Help
 
Thanks for your help.

A.S.


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