Particle dispersion model with LES?

mittal · October 28, 2010, 20:17

Hi,

Is there any dispersion model available for particle tracking with LES in Openfoam ? I found three models in openfoam:

1) StochasticDispersionRAS
2) none
3) GradientDispersionRAS

First and last option can not be used with LES and gives error as they seem to be based on RANS turbulence modeling?

Can some one please comment and guide me?

Many thanks,
Kushagra

matejfor · October 29, 2010, 12:13

Hi,
as you write the only dispersion model available for LES is none, which probably does not do what you want. The question is: Do you need a dispersion model for your LES simulation? What is the Stokes number of your particles, what is your particle time scale compared to the timescale of unresolved turbulence?

If you really need it, it should not be difficult to write your own following the RAS model as a template and some LES dispersion model from the literature.

btw. there is a dummy LES dispersion implementation in spray class of dieselSpray.

good luck

matej

mittal · October 29, 2010, 15:50

Dear Matej,
Thank you very much for your help.

I will look in to details you pointed out and get back to you.
Thanks once again,
Regards,
Kushagra

October 28, 2010, 20:17	Particle dispersion model with LES?	#1
mittal New Member Kushagra Mittal Join Date: Mar 2009 Posts: 15 Rep Power: 17	Hi, Is there any dispersion model available for particle tracking with LES in Openfoam ? I found three models in openfoam: 1) StochasticDispersionRAS 2) none 3) GradientDispersionRAS First and last option can not be used with LES and gives error as they seem to be based on RANS turbulence modeling? Can some one please comment and guide me? Many thanks, Kushagra

October 29, 2010, 12:13		#2
matejfor Senior Member matej forman Join Date: Mar 2009 Location: Brno, Czech Republic Posts: 182 Rep Power: 17	Hi, as you write the only dispersion model available for LES is none, which probably does not do what you want. The question is: Do you need a dispersion model for your LES simulation? What is the Stokes number of your particles, what is your particle time scale compared to the timescale of unresolved turbulence? If you really need it, it should not be difficult to write your own following the RAS model as a template and some LES dispersion model from the literature. btw. there is a dummy LES dispersion implementation in spray class of dieselSpray. good luck matej Linmunn likes this.

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October 29, 2010, 15:50		#3
mittal New Member Kushagra Mittal Join Date: Mar 2009 Posts: 15 Rep Power: 17	Dear Matej, Thank you very much for your help. I will look in to details you pointed out and get back to you. Thanks once again, Regards, Kushagra