Differences between RNG and RS

September 3, 2003, 10:19

hi,

I am running an analyses which has swirling flow from a pipe entering a converging cone. When I use the K epsilon RNG model I get a Rankine vortex within the cone however when i use the Raynolds stress model I get a forced vortex. I am struggling to understand why these differences occur. I was hoping that somone may be able to shed some light into why the differences in the models may occur. I cannot get any physical data in order to verify the cfd models. Can anyone reccomend a good text of source of information which may help me decide which vortex is the most likely result

September 5, 2003, 07:36

Hi, I'm not expert in the subject, but I think you could have a look at the paper:

Vortex breakdown: a review Progress in Energy and Combustion Science Volume: 27, Issue: 4, 2001, pp. 431-481 Lucca-Negro, O.; O'Doherty, T.

Moreover, you could have a look at some fundamental books on turbulence and turbulence modeling, such as:

Turbulent flows, by S. Pope

Turbulence modeling for CFD, by David C. Wilcox

Regards,

Ale

September 3, 2003, 10:19	Differences between RNG and RS	#1
phil Guest Posts: n/a	hi, I am running an analyses which has swirling flow from a pipe entering a converging cone. When I use the K epsilon RNG model I get a Rankine vortex within the cone however when i use the Raynolds stress model I get a forced vortex. I am struggling to understand why these differences occur. I was hoping that somone may be able to shed some light into why the differences in the models may occur. I cannot get any physical data in order to verify the cfd models. Can anyone reccomend a good text of source of information which may help me decide which vortex is the most likely result

September 5, 2003, 07:36	Re: Differences between RNG and RS	#2
Ale Guest Posts: n/a	Hi, I'm not expert in the subject, but I think you could have a look at the paper: Vortex breakdown: a review Progress in Energy and Combustion Science Volume: 27, Issue: 4, 2001, pp. 431-481 Lucca-Negro, O.; O'Doherty, T. Moreover, you could have a look at some fundamental books on turbulence and turbulence modeling, such as: Turbulent flows, by S. Pope Turbulence modeling for CFD, by David C. Wilcox Regards, Ale