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-   -   Implicit scheme for incompressible flow problems (http://www.cfd-online.com/Forums/main/5025-implicit-scheme-incompressible-flow-problems.html)

Triton August 10, 2002 11:00

Implicit scheme for incompressible flow problems
 
I'm solving incomprssible Navier-Stokes equations with artificial compressibilty method. In order to use large pesudo time step, I use implicit scheme to integral in time. The converged solution, where all the dq terms drop to machine zero, is found to be dependent on cfl number. Is this normal? If there are any problems, what could the problems be?

versi August 12, 2002 22:59

Re: Implicit scheme for incompressible flow proble
 
Solutions of some schemes such as Macormack, Strang type splitting, really dependent on time step. You will be required to give specific scheme used so that others can answer you.

j.p.rao pasupuleti August 16, 2002 08:22

Re: Implicit scheme for incompressible flow proble
 

Andy Froncioni August 24, 2002 09:45

Re: Implicit scheme for incompressible flow proble
 
The answer is: when you have reduced the time step to the point where your solution no longer changes much, you will have properly modeled your system.

It is vitally important to make sure that your solutions are properly converged in time and in space.

Implicit schemes guarantee stability, not accuracy, in time.

roro August 25, 2002 04:54

Re: Implicit scheme for incompressible flow proble
 
what is the problem you are working for?

Maybe the problem is sensitive to disturbence.


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