Meshing

griff02 · March 18, 2010, 20:15

Hi
I am trying to describe why distorted elements give bad results in FEA and CFD programs for my final year project and cannot find an explanation anywhere. Can anyone help???
Thanks
Oli

jchawner · March 20, 2010, 13:57

Oliver:

Here's a place to start: distortion may reduce numerical accuracy because numerical approximations are no longer centered (or symmetric) about the centroid of the volume element. (from http://www.flow3d.com/cfd101/cfd101_grid.html)

Ahmed · March 20, 2010, 14:25

no matter what discretisation scheme is used, you end up with a matrix that has to be solved.
see what causes the solution of a matrix difficult/inaccurate then trace it back to the distorted mesh elements

julien.decharentenay · March 22, 2010, 08:30

You may be interesting in reading through http://powerlab.fsb.hr/ped/kturbo/Op...jeJasakPhD.pdf

The section on discretisation contains a discussion on orthogonality and others things to pay attention to in the meshing process.

griff02 · March 23, 2010, 08:06

Thanks guys, this is really helpful

March 18, 2010, 20:15	Meshing	#1
griff02 New Member Oliver Griffiths Join Date: Mar 2010 Posts: 2 Rep Power: 0	Hi I am trying to describe why distorted elements give bad results in FEA and CFD programs for my final year project and cannot find an explanation anywhere. Can anyone help??? Thanks Oli

March 20, 2010, 13:57		#2
jchawner Senior Member John Chawner Join Date: Mar 2009 Location: Fort Worth, Texas, USA Posts: 172 Rep Power: 6	Oliver: Here's a place to start: distortion may reduce numerical accuracy because numerical approximations are no longer centered (or symmetric) about the centroid of the volume element. (from http://www.flow3d.com/cfd101/cfd101_grid.html) __________________ John Chawner / jrc@pointwise.com / www.pointwise.com Blog: http://blog.pointwise.com/ on Twitter: @jchawner

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Best Meshing scheme for Cylinder	Nutrex	Main CFD Forum	4	July 29, 2008 11:03
ICEM Meshing	Jaloha	CFX	0	April 1, 2008 06:24
Meshing locks workbench window.	andy2o	CFX	0	February 1, 2008 05:01
Singularity of grid?Volume meshing vs face meshing	Ken	Main CFD Forum	0	September 4, 2003 11:09
Volume Meshing & Face Meshing? singularity of grid	ken	FLUENT	0	September 4, 2003 11:08

March 20, 2010, 14:25		#3
Ahmed Senior Member Ahmed Join Date: Mar 2009 Location: NY Posts: 240 Rep Power: 7	no matter what discretisation scheme is used, you end up with a matrix that has to be solved. see what causes the solution of a matrix difficult/inaccurate then trace it back to the distorted mesh elements

March 22, 2010, 08:30		#4
julien.decharentenay Senior Member Julien de Charentenay Join Date: Jun 2009 Location: Australia Posts: 163 Rep Power: 5	You may be interesting in reading through http://powerlab.fsb.hr/ped/kturbo/Op...jeJasakPhD.pdf The section on discretisation contains a discussion on orthogonality and others things to pay attention to in the meshing process.

March 23, 2010, 08:06		#5
griff02 New Member Oliver Griffiths Join Date: Mar 2010 Posts: 2 Rep Power: 0	Thanks guys, this is really helpful