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Chetan Shah September 30, 2003 08:33

startup required for Combustion
Hello I am doing Masters in Jet Propulsion..

I want a combustion analysis of a combustor followed by 34 tubes. It is a part of LDO(Liquid Diesel Oil fired) Hot Air Generator.

I have tried with species transport method but analysis could not get started with combustion. Had given a injection of Kerosene (for trial).

Please specify the correct method & procedure to be applied. Whether I should use Injection, Discreate Phase method or any other method???

My conf is for non premixed combustion problem. If u have PDF for LDO please send me that file.


Jin-Wook LEE September 30, 2003 20:30

Re: startup required for Combustion
What's the exact meaning of 'could not get started with combustion' ? Does it mean that combustion process does not occur numerically, or evaporation does not occur ?

I think that other expert can not answer you for your problem because of unclear question. If you specify your problem more detaily, someone can help you.

Sincerely, Jinwook

Chetan Shah October 1, 2003 07:26

Re: startup required for Combustion
I do agree,

Yes Combustion is not started numerically or may be evaporation is not started ....

I am very new to combustion model, I don't know that which method will solve my simple problem of injecting LDO in combustion chamber... In reall problem to start the combustion there is a spark plug to Ignite the fuel flow & Air mixture... for Ignition what is to be used??


Jin-Wook LEE October 6, 2003 00:01

Re: startup required for Combustion
1. Liquid Fuel : For most liquid fuel combustion, DPM is used for droplet injection, becasue mass fraction and volume fraction of liquid fuel is fairly small, less than 10% for mass fraction and less than 1% for volume fraction. I recommend that DPM for fuel injection and vaporization.

2. Vaporization/Boiling. If your initial temperature is lower than vaporization(or boiling) temperature, there is no vaporization(or boiling). So initialize the field by higher temperature.

3. Gaseous Combustion : After vaporization, there is gaseous combustion. You may use finite rate model(chemical kinetics controlled combustion) or eddy dissipation model(turbulent mixing controlled combustion), or the combination of two. In general, combination of two models is right way. However, eddy dissipation model is fairly good approach, which is relatively easy for convergence and relatively easy to setup the case.

4. Combustion Startup : If you use finite rate model or combined model, numerical ignition may be required. It can be done by initializing or patching higher temperature in the field.

Sincerely, Jinwook

chetan shah October 6, 2003 04:03

Re: startup required for Combustion
Thank you sir,

Let me do some R&D, if there will any problem I will come back

Thank you again

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