Unphysical Rise of Water-surface near tail-gate
 

I have been trying to simulate a flow over a spillway and in doing so I am looking to control the depth of water using a tailgate. The turbulence model is RAS;kOmega.

The issue herein is that there seems to be a bulge in the water level near the weir/tailgate (downstream of the spillway) which is rather unphysical. What could be the reason?

Hi!


What you see is a hydraulic jump. I think it is not unphysical.
Google it and you will find more about this phenomenon.

I do know that a jump is occurring at the weir but what I am saying is, the form of the jump (the shape i.e.) isn't what it is like in experimental setups - wherein the water surface is flat till the weir cross-section and thereafter drops.

you have your inlet too close to the weir. In fact, you are incorrectly reproducing the forebay, since what I assume you are expecting is a tranquil flow (M3) upstream.