Free surface river flow

Anonymous — Wed, 23 Jan 2019 13:10:59 GMT

Hello everyone,

Trying to simulate the flow of a river, I come across a phenomenon of a large returning wave from where the water is supposed to be flowing out. Please see pictures below. I wonder what can be the reason for this? Some more detail on the simulation;

Water flows in the river at ~2m/s

From the side a pipeline brings another water line in at ~6m/s

Water leaves at outlet (p=0)

Time step 0,04s (i measured the time it would take the water to go through the smallest mesh i manually measured)

I refined the mesh over the surface of water through adding a region. Although not sure if I succeeded (mesh picture attached)

I did do simulations with finer mesh, smaller time steps (0,01s), but still encountered the same problem.

Although I still think it may have something to do with mesh size, I still wanted to make sure by asking here. May I be missing something else? Any help/suggestion is appreciated!

mesh crinkle cutmesh

3s6s7,5s9s10,5s

topic Re: Free surface river flow in CFD Forum

Free surface river flow

Re: Free surface river flow