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

extracting K and Epsilon from Spalart Allmaras

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 6, 2006, 01:11
Default extracting K and Epsilon from Spalart Allmaras
  #1
Sundar
Guest
 
Posts: n/a
Hi, I am working in an Aeroacoustics of Jet. Based on the paper by Craig Hunter, I have developed a code to calculate the SPL for the jets. I use Fluent to compute the flow.

The aeroacoustic code requires K, Epsilon and the Reynolds stresses to calculate the SPL. We are trying to test different turbulence model to match our experiments, and we beleive that Spalart Allmaras model might have good conformance with the results.

Now, as the Spalart Allmaras model is based on Eddy viscosity, the question arises of how to calculate the terms K and Epsilon.

Can anyone throw a light on that?

Regards, Sundar
  Reply With Quote

Old   July 7, 2006, 06:08
Default Re: extracting K and Epsilon from Spalart Allmaras
  #2
mar
Guest
 
Posts: n/a
I don't think that Spalart-Allmaras is a good choice because this model has been developed for airfoil configurations (it contains a notion of distance from the wall). Anyway it is not correct to obtain k and eps from the eddy viscosity because the relation is not invertible (you cannot obtain 2 parameters from one). The only think you can do is to suppose that Spalart Allmaras contains the same hypotesis of the one equation model (which is an equation in k) and use this relation to obtain only k. However this hypothesis is not so smart for jet-noise prediction!!!
  Reply With Quote

Old   July 7, 2006, 06:13
Default Re: extracting K and Epsilon from Spalart Allmaras
  #3
Sundar
Guest
 
Posts: n/a
I was thinking the same. Thanks for your inputs. As an additional information from my study, when I tried with different turbulence models (in Fluent), Spalart Allmaras model had the highest velocity decay.
  Reply With Quote

Old   July 30, 2006, 04:34
Default Re: extracting K and Epsilon from Spalart Allmaras
  #4
davood rashidi
Guest
 
Posts: n/a
I need information about SPALART ALLMARAS model. beacuse of I want use this model for solve my final MS poroject. pleas help me. thancks alot davood rashidi aerodynamic engineer from KNTU univercity
  Reply With Quote

Old   July 31, 2006, 03:02
Default Re: extracting K and Epsilon from Spalart Allmaras
  #5
mar
Guest
 
Posts: n/a
The main paper is:

P.R. Spalart and S.R. Allmaras, A one equation turbulence model for aerodynamic flows. La Recerche Aerospatiale 1994; 1:5-21.

using Google you can find many papers in which this model is used.
  Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
SimpleFoam k and epsilon bounded nedved OpenFOAM Running, Solving & CFD 16 March 4, 2017 09:30
Orifice Plate with a fully developed flow - Problems with convergence jonmec OpenFOAM Running, Solving & CFD 3 July 28, 2011 06:24
How to get reference to k and epsilon in the epsEqn and kEqn cfd_explorer OpenFOAM Programming & Development 0 March 10, 2011 11:16
How to get reference to k and epsilon in the epsEqn and kEqn cfd_explorer OpenFOAM 0 March 10, 2011 10:58
SimpleFoam k and epsilon bounded nedved OpenFOAM Running, Solving & CFD 1 November 25, 2008 21:21


All times are GMT -4. The time now is 10:04.