CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

? on mixed formulation for incompressible flow

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

LinkBack Thread Tools Display Modes
Old   July 19, 2002, 21:38
Default ? on mixed formulation for incompressible flow
Posts: n/a

I am developing a parallel code for transient incompressible N-S using finite element method. for some reasons I like to use mixed formulation and element-by-element architecture. To make sure the iteration converges and converges in a nice way, I have to find a good preconditioner for the linear solver, which must be invertible and can be inverted quickly and should use as less as possible memory storage. A matrix created by the diagonal terms of the global stiffness matrix (which in fact is never assembled in EBE) with all other terms set to zero is my favorite.

However, due to absence of pressure in continuity equation, the matrix I got inherently has zeros on the diagonal.

I heard there are ways to get around this difficulty, but what are they?
  Reply With Quote

Old   July 22, 2002, 09:00
Default Re: ? on mixed formulation for incompressible flow
Seb Perron
Posts: n/a
1) Look for penalty methods, projection schemes, artificial compressibility. 2) When dealing with incompressible flows with FEM methods (or other discretization schemes): is it almost mandatory to use different space of approximation for velocity and pressure to avoid false pressure modes.
  Reply With Quote


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
Fully Developed Flow in Star-cd SMM STAR-CD 0 September 5, 2011 22:08
Penalty vs mixed formulation in FEA m. malik Main CFD Forum 0 April 8, 2005 14:57
Multiphase flow modeling Paul CFX 2 August 11, 2003 09:41
mixed subsonic/supersonic flow at an inlet BC sascha Main CFD Forum 1 March 11, 2003 05:46
Question on 3D potential flow Adrin Gharakhani Main CFD Forum 13 June 21, 1999 05:18

All times are GMT -4. The time now is 21:31.