Hi Xu, It has been a while since I had fun with using the stability solver, so I might be mixing something up. I am not sure as to why your simulation stops, but could you possibly try with a larger mesh? Could it be that the mesh you are using, when partitioned, result in a small number of elements per core? Also, have you tried running the pure 2D case without the homogeneous expansion in parallel, and did it behave the same - i.e. just stops? Best, Stan On czw, 2018-11-15 at 16:57 +0100, Xu Chu wrote:
Hi Stan,
thank you very much. I tried it, it works!
I have another question about the ARPACK and modified Arnoldi. I am now using ARPACK for BiGlobal LST (2D base flow), which is serial. I tried to use modified Arnoldi, which should be parallel. But it runs parallel only with up to 4 cores. If more cores are given, it just stopped there without results output. Does it have anything to do with the limited mode (single mode) in the spanwise direction? I already try direct solver, multigrid and XXT.
Best,
Xu
On 11/09/2018 09:52 AM, Stanisław Gepner wrote:
Hi Xu,
You need to manipulate the Lz parameter which specifies the distance over which the expansion is performed (Lz=2Pi / Beta).
Best, Stan
On czw, 2018-11-08 at 17:54 +0100, Xu Chu wrote:
Dear Nektarers, I am running a 3D direct stability analysis test case, the Re15000 Channel Flow from the tutorial (PPF_R15000_3D, ARPACK as the solver). As I understand, this is a BiGlobal stability analysis with 2D base flow and the spanwise wavenumber Beta. It means that for a given Beta, the Eigenvalues can be calculated. What I am seeking is the Eigenvalues under different spanwise wavenumber Beta, so I turn "Beta Set To Zero" as false (as in the PPF_R15000_3D). And the solver converged showing 4 Eigenvalues with Real and Imaginary part of each, with no information of Beta. How can I find the Eigenvalues under different spanwise wavenumber Beta? Thank you very much.
Best Regards, Xu
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