PKweir with Flow-3D 9.3
 

Hello dears users of Flow-3D,

I need help concerning the modelling of a flow over a PKweir (sort of labyrinth weir), The problem is the geometry of that structure. Which mesh should I use? Has anybody already make such simulation?

Thanks

Julien

PK weir simulation? It's very exciting!
 

Hi, Julien.

Will you simulate PK weir? Wow, it's very exciting!

Making the geometry is easy if you can use 3rd-party CAD S/Ws. When I make geometry of structure as STL file, I use Solid Edge version 20. How about using it?

If you need a help and send me the drawing of structure, I can help making STL file and show some input file. (I have a input file of labyrinth weir simulation.)

Good luck!

Re: PK weir simulation? It's very exciting!
 

Hi Byongjun Park,

In fact, the geometry is not exactly my problem : using Autocad 2005 (a bit old, but efficient!), I have already a good solid (stl). I have already run simulations, but I am a bit far away from the referency data (specific flowrate)...I don't know where it comes from...I suspect my mesh...

I have read about labyrinth weir simulation (Brains versus Brawn: The Changing World of Hydraulic Model Studies), with very good results...but still don't know how the have proceeded.

Do I need more cells?(already 40 000 000), more fixed points, or are there any options of calculation I should use?

Julien

Re: PK weir simulation? It's very exciting!
 

40 million is a lot more than is usually required. I suspect the mismatch in the flow rate is to do with the boundary conditions are the mesh edges.

Michael

Bcdata in PK weir simulation
 

Hi Michael,

I have also thought about that...I have put specified pressure a the left boundarie, and imposed the fluid height (in stagnation pressure). At the right side, I have set Outflow. In Y direction symmetry condition are set.

Have you got any other idea?

Thanks

Re: Bcdata in PK weir simulation
 

Outflow BC may be ok for a supercritical flow. For subcritical, it is better to define pressure with a surface height, otherwise, the problem is not well defined.

Michael

Re: Bcdata in PK weir simulation
 

Thanks a lot. I will try this and then tell you about it!

Julien

Re: Bcdata in PK weir simulation
 

Well thanks a lot Michael, I have already better results for my flowrate trought my PK weir.

Julien

Re: Bcdata in PK weir simulation
 

Glad to here this, Julien.