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


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

Like Tree1Likes
  • 1 Post By sureshkumar

LinkBack Thread Tools Display Modes
Old   June 9, 2006, 01:20
Default multigrid
Posts: n/a
Hi sir,

Please spend sometime for me….Myself Sureshkumar doing in IIT-india. I am doing project on multigrid method…..i am solving 2D lid driven cavity problem with collocated finite volume method(SIMPLE algorithm) approach with Full approximation scheme of multigrid method. I got the results for multigrid 2 level and almost reduction to 40% time that has taken by single grid but I was not getting solution for multigrid 3 level which will take very less time. So I am telling a procedure of multigrid 2 level in a brief manner that what I had done ,so help me how to extend it for 3 level. I am following Peric's paper"Finite volume multigrid prediction of laminar natural convection:bench mark solutions",IJNMF,1990.

v-cycle multigrid 2 level:

1. solving u,v, pressure correction equations on finegrid for some global iterations in the same procedure of finite volume SIMPLE algorithm procedure.

2. Then calculate residuals of u and v and transfer these restricted residuals to coarse grid added as a extra source term, and also restricted u and v values to coarse grid.

3. The main thing is transferring mass fluxes from fine to coarse grid i.e. the initial mass fluxes are conservatively evaluated by summing the fine grid mass fluxes through the corresponding control volume faces. And these coarse grid mass fluxes are only be corrected in the course of coarse grid iterations.

4. On coarse grid ,solving u, v, pressure correction equations for some global iterations to calculate corrections to finegrid u ,v and p_dash values.

5. Then prolongated these variables to fine grid and same v-cycle procedure is repeated.

Doubts regarding v-cycle multigrid 3-level:

upto third level I followed the same procedure of 2-level but when we prolongated u,v and p_dash from very coarse level to medium coarse level what must I have to take care, mainly how to take mass fluxes for intial iteration of medium coarse grid.

Can u tell where I was doing wrong…..and if possible explain in a brief manner how to come from very coarse to medium coarse followed by finegrid………please help me in this regard……….i am waiting for ur reply………..

Thanking u in advance

mb.pejvak likes this.
  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
LES by Multigrid mnabi Main CFD Forum 8 July 11, 2009 20:21
Multigrid method Suresh kumar Main CFD Forum 1 April 24, 2006 20:07
MULTIGRID at the wall Jim Main CFD Forum 0 February 19, 2003 13:22
Multigrid: AMG GMG FMG J Roued Main CFD Forum 1 June 28, 1999 08:12
Multigrid applied to k-e models Paulo Zandonade Main CFD Forum 9 May 24, 1999 08:10

All times are GMT -4. The time now is 20:17.