Simulation of a retention filter basin as a beginner
 

Hello everyone,

I'm student and got the offer to write my master thesis about a cfd simulation of a retention filter basin with OpenFOAM.
The Simulation shall include one run under free water level conditions (water + air) and a second run including the particles. Below are some screenshots of the planned geometry. I also shall investigate the effect of guide plates within the feed gutter.

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Now I've never really worked with OpenFOAM (just doing some tutorial stuff and so on) and have no C++ skills.
My question to you is if anyone can tell how hard it is to do a simulation of such an object (finding the rights boundary conditions, equation solver etc.) and if it's realistic for me to get this done?

I dont understand why is it important to have the air phase in the simulation

Well me neither.. it's just that I've already got the results of this simulation from another office and they said it like that in their final report. But like I said, I am new to OpenFOAM and quite new to CFD simulations so this is not the important part for now.

I cannot guarantee you'll scape from having to program something if you use OF, or any other cfd software for that matter... what i can assure you is that is doable, and doesnt require a phd level work, granted that some assumptions are made. Mi initial suggestion would be to use VOF (air+water) just to get a 3D shape of your free surface. Fron there you consteuct your grud based on that surface.
I would even use a shallow water model to get the free surface, and a oid resolving the air phase entirely. You are interested in the dynamics over the porous bed anyway

Okay. Thank you so far.

Can someone tell me if its possible to import the geometry from AutoCAD into OpenFOAM?
Or which software is best to use for building the geometry?

If you export your geometry as stl you can use snappyHexMesh. Otherwise there are commercial mesher (e.g. pointwise) which can directly export the mesh in OF format.