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Re: KSP/PC choice



Dear Lissandro,

On Mon, 23 Jul 2007, Lisandro Dalcin wrote:

On 7/23/07, Tim Kröger <tim@xxxxxxxxxxxxxxxxxxx> wrote:

the more KSP and PC methods are available, the more difficult it is to choose a suitable one.

I want to compute Navier-Stokes (using Finite Elements) for
medium-sized Reynolds numbers (still laminar, though).  I am currently
using

Are you solving incompresible flow?

Yes.

Tansient or steady state?

Transient.

Are you using a monolithic formulation; or a fractional-step like formulation?

Monolithic. (I am not quite sure about this word but I assume it means that I don't try to decouple the two equations.)


What kind of stabilization for advection and pressure are you using?

Streamline diffusion (for advection). I am not aware of the requirement to stabilize the pressure as well.


I ask this because in my experience incompressible flows with
monolithic formulations are usually hard to solve, and a good choice
of stabilization method not only leads to better final solution, but
also lead to linear systems with better conditioning.

Would you recommend to use a fractional step method? Would you recommend a different stabilization method? If you have any suggestion, please let me know.


Best Regards,

Tim

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