Hi,

I am testing my SIMPLER code for incompressible fluid in a pipe. The problem is for the unsteady state solution the pressure field ossilates in the first several iterations (becomes negative and positive). The mass balance is conserved and I have fixed the pressure at the outlet and also fixed normal velocity at the inlet. You you tell me where I might have made the mistake?

Could you send a copy to me? I want to check it on my project.

Email:seaspace@sina.com

My personal recommendations for your references.

1. check the terms of boundary conditions in your algebra matrix. 2. check the solver of the matrix. 3. check the size of time step and space discretization for scheme stability.

Thanks a lot. The main problem is the pressure for the transient part. I am sure that the solution for the steady state is correct but for the transient part it's wrong.