Hi Turbulent Viscosity

April 12, 2005, 16:39

Hi all,

I am simulating unsteady 2D flow past a bluff body with Re. approx. 5e6 and using the standard k-e model.

I find the peak turbulent viscosity ratio is around 1.5e5 in the wake. This seems very high, but I can't find quantitative values in the literature to compare against.

Can anyone suggest where I might find these, and if my ratio is too high - what is going wrong?

Thanx, Shuto

April 14, 2005, 22:14

I doubt here if std k-e model apropriate for such condition. you may rather try RSM in this case. Also check for the enough mesh density near the body.

-us

April 15, 2005, 14:17

t'aint the best I know, using RNG k-e now. Doesn't need to be wonderful, just give overall values of forces comparable to experiments.

Anyone know where I can find reference to wake turbulent viscosity? I have searched hi and lo and can't find anything.

Shuto.

April 24, 2005, 08:58

Dear Shuto You can find experimental results in the book

"Viscous fluid flow" by frank white otherwise e-mail to send you more info sincerely Mehdi

April 12, 2005, 16:39	Hi Turbulent Viscosity	#1
Shuto Guest Posts: n/a	Hi all, I am simulating unsteady 2D flow past a bluff body with Re. approx. 5e6 and using the standard k-e model. I find the peak turbulent viscosity ratio is around 1.5e5 in the wake. This seems very high, but I can't find quantitative values in the literature to compare against. Can anyone suggest where I might find these, and if my ratio is too high - what is going wrong? Thanx, Shuto

April 14, 2005, 22:14	Re: Hi Turbulent Viscosity	#2
us Guest Posts: n/a	I doubt here if std k-e model apropriate for such condition. you may rather try RSM in this case. Also check for the enough mesh density near the body. -us

April 15, 2005, 14:17	Re: Hi Turbulent Viscosity	#3
Shuto Guest Posts: n/a	t'aint the best I know, using RNG k-e now. Doesn't need to be wonderful, just give overall values of forces comparable to experiments. Anyone know where I can find reference to wake turbulent viscosity? I have searched hi and lo and can't find anything. Shuto.

April 24, 2005, 08:58	Re: Hi Turbulent Viscosity	#4
Mehdi Ghoddosy Guest Posts: n/a	Dear Shuto You can find experimental results in the book "Viscous fluid flow" by frank white otherwise e-mail to send you more info sincerely Mehdi

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