incompressible NS solver with multi-block structured grid

Geon-Hong · March 14, 2012, 23:44

Hello,

I recently wrote an incompressible Navier-Stokes solver code to deal with multi-block structured grid and immersed boundary method.

When I run sample cases with different Re conditions, I found some problem in my code.

When I run the case with Re of 100, it seems to work properly. But when I increase the Re to be 1000, then a certain source of error comes into play.

I attached the figures of results with different Re.

Why are problems? Does anybody have an idea on it?

I used preconditioned Bi-CG stab solver instead of LDU type solver to deal with asymmetric matrix due to block(refinement) interfaces.

The flow field behaves like checker board problem in some block interfaces.

I need your help orz

Best regards,
Geon-Hong

arjun · March 15, 2012, 00:58

does not look like checker boarding to me. It looks like your convection term is creating unwanted sources. If this is the case first order upwind scheme should work fine. (for testing purposes).

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
AnSys Structured Grid Development	douglas frongillo	Main CFD Forum	1	November 1, 2007 04:56
Block Structured Grid	aurel	Main CFD Forum	0	June 21, 2007 02:19
matrix solver about block structured grid	young min, Sohn	Main CFD Forum	1	July 11, 2000 19:35
Grid generator for structured grids	Tore Myhrvold	Main CFD Forum	5	January 21, 1999 08:09
Incompressible flow solver (staggered grid)	J. Ehrhard	Main CFD Forum	1	October 8, 1998 19:47

March 15, 2012, 00:58		#2
arjun Senior Member Arjun Join Date: Mar 2009 Location: Nurenberg, Germany Posts: 1,273 Rep Power: 34	does not look like checker boarding to me. It looks like your convection term is creating unwanted sources. If this is the case first order upwind scheme should work fine. (for testing purposes).