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

ILU Factorisation

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

Like Tree2Likes
  • 1 Post By Paul
  • 1 Post By Anthony Wachs

LinkBack Thread Tools Search this Thread Display Modes
Old   May 30, 2002, 14:49
Default ILU Factorisation
Posts: n/a
hello everybody i want to solve a 2d square grid u''(x)+u''(y)=f(x,y) using ILU ( incomplete lower upper )factorisation. Please anyone help with a related text or solution. Thanks in advance rahul
  Reply With Quote

Old   May 30, 2002, 23:21
Default Re: ILU Factorisation
Posts: n/a
You may refer to Numerical Recipes (C/Fortran) at or
Quasar_89 likes this.
  Reply With Quote

Old   May 31, 2002, 05:54
Default Re: ILU Factorisation
Anthony Wachs
Posts: n/a
Just a simple question : why incomplete factorization ? Why don't you consider all the terms in your factorization and calculate the complete LU ?

Moreover the laplacian operator involved in your equation is symmetric, thus you may use the LLt factorization (Cholevski) which is faster (half the time) since you only have to perform the L matrix calculation instead of L and U

As Paul mentioned, you are likely to find all the algorithms you need on

Hope it could help, Anthony
Quasar_89 likes this.
  Reply With Quote

Old   June 6, 2002, 00:32
Default Re: ILU Factorisation
Posts: n/a
Sir i am working on research project "revemping of Francis Turbine applying CFD". I have got book "An introduction to computational fluid dynamics (finite volume) by malalasakra" it is very good book and i have understand SIMPLE, SIMPLER AND SIMPLEC method of solving Navier Stock equation but in this book just presentation that how Navier Stock equation can be solved but there is no solve example. Do you know any book or article in which this type of example is present. I mean that for any given problem(good if turbine rotor)firstly assume pressure field and then find velocity field then check pressure correction equation and repeat this procedure still convergence occure. waiting for your prompt reply thanks
  Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
ILU for Navier stokes problems Raju Main CFD Forum 5 July 29, 2006 15:15
approximate factorisation dist Main CFD Forum 5 November 4, 2005 07:00
approximate factorisation sebed Main CFD Forum 0 October 19, 2005 19:18
ILU Preconditioning with BiCGSTAB Emmanuel O.B. Ogedengbe Main CFD Forum 2 October 16, 2004 17:26
ILU decomposition in GMRES/ILU(0) method Jian Xia Main CFD Forum 2 October 14, 2000 12:42

All times are GMT -4. The time now is 07:40.