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

3D case of prandtl-meyer expansion

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 8, 2001, 14:17
Default 3D case of prandtl-meyer expansion
  #1
AG
Guest
 
Posts: n/a
what you have said pleasantly hold for a neck like ___________ ___________ > where r is large.

but does it also hold for a neck where the neck radius is quite small.like in my case the -- --> _________ flow ---<_________ - ---> |

| i have

to apply the turning here.

at r->0

(1). In the book "elements of gasdynamics" by Liepmann and Roshko, published by John Wiley & Sons, exercise of Chapter 12, problem 12.3, it says "Show that in the expansion over the shoulder of an axially symmetric body the pressure change is given by the two-dimensional, Prandtl-Meyer theory. Hint:Just at the shoulder,(1/w)*(dw/ds) is much greater than (sin(theta))/r." (2). The equation of motion for axially symmetric flow is given by equation-12.10. See Chapter-12, the method of characteristics. (3). In other words, 2-D Prandtl-Meyer theory (or approximation) is good for axially symmetric flow over the shoulder.
  Reply With Quote

Old   April 8, 2001, 15:08
Default Re: 3D case of prandtl-meyer expansion
  #2
John C. Chien
Guest
 
Posts: n/a
(1). Small is relative. As long as it is not "zero", it should be all right. (2). After all, it is just one local area. (3). I am getting the feeling that if you still have the question, then it is better to buy a commercial CFD code and then ask additional questions in the commercial codes forum. (just a joke) Don't be afraid of trying out different approaches. You may also want to try the MOC , because it is the exact method for supersonic inviscid flow.
  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
Instable natural convection case Peter88 OpenFOAM 5 August 18, 2011 01:23
Interfoam Droplet under shear test case adona058 OpenFOAM Running, Solving & CFD 3 May 3, 2010 18:46
Cloning a case or creating a new case for 16 processes mellanoxuser OpenFOAM Running, Solving & CFD 0 February 8, 2008 16:52
HELP!! Prandtl numbers in RNG k-e turbulence model maoasis FLUENT 0 April 24, 2006 10:51
New case Constantinos Zervides (Zervides) OpenFOAM Pre-Processing 5 October 24, 2005 03:34


All times are GMT -4. The time now is 16:38.