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

Neuwton Raphson algorithm

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

LinkBack Thread Tools Display Modes
Old   April 3, 2003, 10:00
Default Neuwton Raphson algorithm
said dhimdi
Posts: n/a
i am busy by solving a non linear system of equations by using the Newton Raphson algorithm.

The problem is: during iterations: when we approach the solution it diverge( probably du to the derivative matrix equal zero), would you please help me solving this hadicap.

  Reply With Quote

Old   April 4, 2003, 13:41
Default Re: Neuwton Raphson algorithm
Posts: n/a
Make sure your matrix is well-posed(eigenvalues not too far off). If not, pre-condition it. Get the correct Jacobian matrices (the derivative matrix). For the final step, Add so-called Marquartz constants to diagonal to "stablize or make the matrix better-posed" the matrix, then iterate the Marquartz solutions, but eventually you got to remove the constant (gradually) to get the real solutions. I don't know that will help you.
  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
About Phase Coupled SIMPLE (PC-SIMPLE) algorithm Yan Kai Main CFD Forum 0 April 18, 2007 03:48
About Phase Coupled SIMPLE (PC-SIMPLE) algorithm Yan Kai FLUENT 0 April 13, 2007 23:17
mach-uniform algorithm for LES/DNS ilyas Main CFD Forum 0 February 22, 2007 11:53
CFD algorithm design with reconfigurable computing Beatríz Navarro FLUENT 0 June 24, 2006 18:22
LES algorithm James Fluroe Main CFD Forum 2 December 27, 2001 18:51

All times are GMT -4. The time now is 08:30.