# Multigrid: AMG GMG FMG

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

 June 28, 1999, 02:22 Multigrid: AMG GMG FMG #1 J Roued Guest   Posts: n/a Hi, I have a simpel question about different multigrid approaches: What is the difference between Algebraic Multigrid, Geometric Multigrid Fuld Multigrid ???? Regards Jens

 June 28, 1999, 08:12 Re: Multigrid: AMG GMG FMG #2 Kaare A Sorensen Guest   Posts: n/a Hi Jens, AMG is an abstraction of traditional multigrid methods (GMG). In AMG you base your approach on the algebraic (hence the name) system Ax=b rather than the physical (PDE-) equations on a geometry (hence ...) where you have the notion of grids. In AMG instead of solving on coarser meshes, you are adding lines in your system of equations. The reason AMG is called a multigrid method even though 'grid' is undefined in its context is that it in some cases is equivalent to the traditional MG approach, and was probably motivated by it. The applicability of AMG seems to be somewhat restricted at the moment, in particular I've only seen it used on linear applications. FMG is not directly related to the definitions above. Rather FMG is a way to generate a good initial guess for the selected MG procedure by obtaining less expensive solutions on coarser meshes (by f.ex. MG) and mapping the solution itself (not the correction) up to the finest grid. Ha en god dag! Kaare

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post more work CD-adapco 8 February 10, 2017 00:17 SamCanuck FLUENT 2 August 31, 2011 11:34 devesh.baghel FLUENT 1 January 17, 2011 02:58 msrinath80 OpenFOAM Running, Solving & CFD 2 November 7, 2006 16:15 Paulo Zandonade Main CFD Forum 9 May 24, 1999 08:10

All times are GMT -4. The time now is 11:24.