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

Transonic flow over a bump

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 5, 2011, 07:33
Default Transonic flow over a bump
  #1
Member
 
Join Date: Jul 2011
Posts: 42
Rep Power: 6
A.D.E is on a distinguished road
Hi am looking to run a CFD case for transonic flow over a bump (using OpenFOAM) and I was wondering if anyone has any data for such a case experimental and/or numerical to validate my results!! Additionally does anyone know if an analytical solution exist??
A.D.E is offline   Reply With Quote

Old   July 6, 2011, 19:07
Default
  #2
Senior Member
 
Martin Hegedus
Join Date: Feb 2011
Posts: 467
Rep Power: 9
Martin Hegedus is on a distinguished road
An option,

http://turbmodels.larc.nasa.gov/bump.html
Martin Hegedus is offline   Reply With Quote

Old   July 7, 2011, 10:38
Default
  #3
Member
 
Join Date: Jul 2011
Posts: 42
Rep Power: 6
A.D.E is on a distinguished road
Hi Martin,

Thank you for your reply and link. Your link is helpful but I am looking for something a bit more technical to better understand the Physics behind such flows.. Do you have anything else in mind such as a chapter from a book and/or a technical paper??

Thank you in advance for your consideration and time!!

Sincerely,
A.D.E
A.D.E is offline   Reply With Quote

Old   July 7, 2011, 13:26
Default
  #4
Senior Member
 
Martin Hegedus
Join Date: Feb 2011
Posts: 467
Rep Power: 9
Martin Hegedus is on a distinguished road
Ooops, sorry I messed up. The link I sent was for Mach=0.2. Hardly transonic. There is the axisymmetric CFL3D (cfl3d.larc.nasa.gov) test cases http://cfl3d.larc.nasa.gov/Cfl3dv6/c...s.html#axibump. It also has a reference to an AIAA paper ("An Investigation of Transonic Turbulent Boundary Layer Separation Generated on an Axisymmetric Flow Model," AIAA 79-1479, 1979). There is also the OVERFLOW bump comparison, http://people.nas.nasa.gov/~pulliam/...OWTO/bump.html. It doesn't give much detail, but the results look similar to CFL3D. So, the AIAA paper may be a good starting point.

From my personal past theory experience, the bump, 2d and axisymmetric, are associated with linear potential flow and shock-expansion theory. They are for zero angle of attack. And of course doesn't include boundary layers. There is also 2nd order shock-expansion. Other than that, I don't know of a relevant paper or chapter for theory. And I guess that will not work since you are interested in testing OpenFOAM at transonic speeds. And, as far as I know, an Euler or NS analytic solution does not exist.

What type of bump are you looking for and what would you like to test, in addition to transonic flow? Are you interested in Euler or NS? Are you interested in separation?

Also, as far as I understand and I'm not sure of the ins and outs of OpenFOAM, but OpenFOAM will not converge for the supersonic portions of the transonic flow since it is a non coupled method. To solve transonic flow, the equations should be coupled. If you are able to converge your residuals to machine zero, let me know.
Martin Hegedus is offline   Reply With Quote

Old   July 8, 2011, 07:25
Default
  #5
Member
 
Join Date: Jul 2011
Posts: 42
Rep Power: 6
A.D.E is on a distinguished road
Thank you for the new links Martin. I am relatively new with OpenFOAM and I was involved in low speed aerodynamics since now. I therefore want to enhance my knowledge on high subsonic and transonic flows as well as to understand the limitations of OpenFOAM. At the moment I am not interested in separation.

If I manage to converge my residuals I will let you know.

Once again thank you for your consideration and time.

Sincerely ,

A.D.E
A.D.E 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
Inviscid Transonic flow of Naca 0012 pankos Main CFD Forum 4 February 13, 2011 05:59
Can 'shock waves' occur in viscous fluid flows? diaw Main CFD Forum 104 February 16, 2006 06:44
Is Fluent v4.5 efficient for transonic flow Pef FLUENT 0 March 8, 2002 11:43
can operation pressure be used to transonic flow? liming.wu FLUENT 1 January 2, 2002 17:38
Star-CD for transonic flow John McArthur CD-adapco 2 April 26, 2001 09:36


All times are GMT -4. The time now is 12:18.