[bill_vl]

I am very new to Flow 3D and currently working on modeling flow over an ogee overflow weir as part of my capstone project. I have topography and bathymetry for my chosen site but first I modeled the geometry in a rectangular channel to see how things went. After some playing around I was able to get successful results and decided I would now work to import my contour data.

All my modeling has been done in AutoCAD or Civil 3D. I first took my contours (2D lines) and made a surface in Civil 3D which I then exported point data into a NEZ format and used the Topo2Stl addon in Flow 3D to create the STL file. Since I took the contours from Civil 3D but made my 3D solids of the dam/weir in AutoCAD, I ended up having to do some translations in Flow 3D to properly position the weir in the topography. This was a minor inconvenience and since it isn't for an actual project, I wasn't worried about any discrepancies in not positioning the structures in the exact location. I am only saying all this because I suspect the process I used might have something to do with my problem.

When I ran the simulation in the "box", I had no issues and the headwater/tailwater came in at the correct elevation and everything looked good, but for some reason, when I do the exact same simulation with the topo inserted, a huge wall of water comes flowing in from both the headpond and tailrace. I have looked through all my settings and can't for the life of me figure out what is going on. The especially odd thing is that if I switch the headwater and tailwater boundary conditions, the correct headwater level comes in at the tailwater and same thing with the tailwater level coming into the headpond.

I understand that to troubleshoot this issue you might need some log data or specific files but being new this software, I am not sure what those are so please just ask if there are additional files I should post.

Thank you
Bill

[bill_vl]

Any advice would be appreciated

[thunde47]

It is hard to tell what the problem might be without looking at the input files and running the actual simulation. Can you please privately send me all the input files and I will try to take a look at them?

Did you procure the license through Flow Science's academic program? If yes, you know where to email directly. If not send it over on cfdonline itself.