CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

turbulent viscosity ratio for jet

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   January 14, 2006, 18:49
Default turbulent viscosity ratio for jet
  #1
serpil
Guest
 
Posts: n/a
Hi everybody, I try to model an axisymmetric jet behind a turbofan exhaust. The problem is that with RANS the turbulent vicosity ratio is on the order of 10e4 which seems to be high physically. There exist two stream; one with Mach 0.4, and corresponding 10% turbulent intensity, and the other with mach 0.2 and 6%turbulence intensity. Is that much turbulent viscosity physical? If not, what can be the reason for that?

Thanking to everyone in advance for time and consideration.

  Reply With Quote

Old   January 17, 2006, 12:23
Default Re: turbulent viscosity ratio for jet
  #2
J. Kim
Guest
 
Posts: n/a
You may have some answers through searching this website.

My suggestion is as follows:

Test your problem by reducing the jet velocity (around 1/100 scale). If you still have the same problem, insert more meshes. or Remesh your domain.

You may try the following schemes together;

Lower relaxation factors, Use different initialization values, Start unsteady simulation at first.

  Reply With Quote

Old   January 17, 2006, 14:51
Default Re: turbulent viscosity ratio for jet
  #3
serpil
Guest
 
Posts: n/a
Dear Kim, thanks a lot for your comments. I will consider your advice.
  Reply With Quote

Old   September 19, 2014, 06:19
Default
  #4
New Member
 
Rachit Singh
Join Date: Nov 2011
Posts: 6
Rep Power: 6
rachitsigh11 is on a distinguished road
Hi serpil..........i am doing simulations for normal shock at Mach = 2 at high altitudes. But i am not able to find what the value of turbulent viscosity ratio would be at such high altitudes and high reynolds number. Can u give some reference for find the value of turbulent viscosity ratio.

Also how u got this value " with RANS the turbulent vicosity ratio is on the order of 10e4". Thanks
rachitsigh11 is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
hel (turbulent viscosity ratio limited) for supersonic combustion problem omar.2002bh FLUENT 2 September 5, 2012 11:04
setting value of turbulent intensity and turbulent viscosity ratio in wind tunnel nuimlabib Main CFD Forum 0 August 4, 2009 00:05
On limiting to turbulent viscosity ratio! varghese FLUENT 2 November 15, 2003 09:56
Problem of Turbulent Viscosity Ratio Limited David Yang FLUENT 3 June 3, 2002 06:13


All times are GMT -4. The time now is 21:38.