CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   Upwind scheme (http://www.cfd-online.com/Forums/cfx/24595-upwind-scheme.html)

KM September 25, 2007 19:45

Upwind scheme
 
Hi there,

I know that upwind scheme should only be used for the initial guess but not for the final results. Can we believe on results from upwind upto an extent, to do some analysis if our model physics is working fine ? Or these results are not good for any kind of analysis ?

Regards, KM.

Glenn Horrocks September 26, 2007 00:21

Re: Upwind scheme
 
Hi,

Problem dependant, so cannot give a general answer. Do a run using both and compare for your application.

Glenn Horrocks

CycLone September 26, 2007 12:10

Re: Upwind scheme
 
Hi KM,

All CFD analysis includes some degree of error. Running with a first order upwind advection scheme simply means that the error is going to be larger for a given grid resolution and therefore will require a much finer mesh to minimize this error.

An easy way to estimate the magnitude of this error is to compare results using upwind to High Resolution or a Specified Blend Factor. You'll find that the difference is largest on a coarse mesh and is reduced as you refine the mesh.

-CycLone

Kushagra Mittal September 27, 2007 15:41

Re: Upwind scheme
 
Thanks a ton ! It helps. :)

Regards, Kushagra.

Kushagra Mittal September 27, 2007 15:41

Thanks: Upwind scheme
 
Thanks a ton ! It helps. :)

Regards, Kushagra.


All times are GMT -4. The time now is 14:43.