[eduard.puig.montella]

Hi Legacy,

Have you started your case from scratch? It is difficult to answer your question without more details on your case. I suggest you start with the tutorial available in sedFoam called 2DPipelineScour. It has a similar geometry, and you should be able to adjust it to match the boundary conditions of your case.

I have adjusted the 2DPipelineScour tutorial (tar.gz file attached) to reproduce an oscillatory flow similar to the one in the article you are referring to. The case runs smoothly, and you can observe the flow reversing in the following picture:



Maybe setting zeroGradient velocity at the outlet will help get rid of the instabilities at the outlet. You should also adjust the geometry to fit your case and make sure the boundary conditions are the same as in the article. For instance, I haven't modified the omega and k inlet conditions to be sinusoidal as in the article.

I hope this setup helps you model the scour as in the article.

2DPipelineScourOscil.tar.gz

[Legacy]

Dear Eduard Puig Montella,

Thanks for quick response. I tried your case and adjusted my the simulation setup similar to the article. I tried different ramp up times but after 9-10 seconds simulation starts to diverge. Here is test case for the article. Could you please have a look at it?

Thanks.

[eduard.puig.montella]

Hi,
I tested your case with a lower Courant number (set to 0.1) and the simulations ran without problems. See the following video:

What version of SedFoam are you using? I am using the latest version, SedFoam2312. If the problem persists, can you tell us where the instabilities are appearing? Is it at the boundary conditions, near the cylinder, at the interface, etc.?

[Legacy]

Thank you for spending time on this. The instabilities appear near the cylinder. My run crashes around t=9.5 seconds. Suspended sediments gets "stuck" to cylinder and it causes sharp gradients in the U.a field.

I am using version 2212. I think it has something to do with my installation. I will give it a try with the docker image of sedFoam.

Thanks again!

[Legacy]

Hi,

I compiled the sedFoam (latest version) with OpenFOAM v2312. I still have the same problem. Attached, please see the instabilities around the cylinder. The suspended sediment "attaches" to the cylinder and leads to instabilities.

You can see on the top left of the cylinder where U.a (vertical component) = -2 m/s.

[eduard.puig.montella]

I am really surprised you are encountering such instabilities because I do not observe them, at least not for the first 15 seconds. Please run the following case without any modifications.

testCase_eduard.tar.gz