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sonali August 13, 2005 03:18

help in burner problem
 
hellow,

i have carried out the simple burner analysis. i am getting satisfactory results in laminar and turbulant flow. i have given air velocity as 10 m/sec and temp of 300 Kand fuel velocity as 2.5 m/sec. and temp of 500 K ..in the initialization i have selected all zones and velocity as 5 m/sec and temperature as 2000 K. my problem is when energy is kept on then solution converges but in post processing the temperature of air in, fuel in and burner body all is taken as 2000 K. whatever temperature i give in the intialization that is taken and ignition doesnot take place. please give your suggestion to solve my problem.

thanks a lot.

sonali

zxaar August 13, 2005 04:44

Re: help in burner problem
 
well you have not mentioned what combustion model you are using.

i guess you are workign with EDC or some model where you solve for all the equations, try smaller underrelaxation. or try gettign intial solution with flamelet model and the iterate further with this model.

Saurav August 13, 2005 11:44

Re: help in burner problem
 
Hi Sonali,

Initialize the flow using a high temperature and non-zero fuel content, this will allow the combustion reaction to begin. "The initial condition acts as a numerical spark" to ignite the fuel-air mixture. This initialization is especially critical when you include finite-rate kinetics in the overall reaction rate.

Regards Saurav


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