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

Very large diag coeff matrix=removed value?

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

LinkBack Thread Tools Display Modes
Old   February 27, 2006, 00:37
Default Very large diag coeff matrix=removed value?
Posts: n/a
Sponsored Links

I'm trying to solve the flow past a square cylinder using the fractional step. For the poisson eqn (or momentum), I need to do something abt the cells occupied by the square cylinder.

One of my mtd is to make the coefficient of the diagonal coefficient of those cells very big hence their values will never change.

Another way is to restructure the system of equations to exclude the cylinder's cells. Hence, for a simple 3X3 (9) cells, we will orginally get a 9X9 matrix to be solved. If the centre cell is removed, we will get a 8X8 matrix instead.

I tried the 2 mtds and found that the answers are different. Should that be so? And is the second mtd a better one for the square cylinder problem?

Thanks in advance
  Reply With Quote
Sponsored Links


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
Postprocessing large data sets in parallel evrikon OpenFOAM Post-Processing 28 June 28, 2016 03:43
Suggested unsteady, implicit solver stable with arbitrarily large time steps djbungee OpenFOAM Programming & Development 45 March 23, 2015 05:14
LES on a scaled geomentry (Mesh and Large scales) comb Main CFD Forum 0 February 8, 2011 07:21
Floworks for simulation of airflow in large rooms. kajaken FloEFD, FloWorks & FloTHERM 1 October 28, 2008 14:58
what happens if y+ is too large or too small Bo Jensen Siemens 12 February 20, 2003 00:31

Sponsored Links

All times are GMT -4. The time now is 07:22.