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Unphysical Rise of Water-surface near tail-gate

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Old   August 18, 2019, 13:20
Default Unphysical Rise of Water-surface near tail-gate
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Pratik Chakraborty
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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?
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Old   August 22, 2019, 04:21
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anonymous
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Hi!


What you see is a hydraulic jump. I think it is not unphysical.
Google it and you will find more about this phenomenon.
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Old   August 22, 2019, 14:48
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Pratik Chakraborty
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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.
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Old   November 18, 2019, 14:12
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Quote:
Originally Posted by pratik_chakraborty View Post
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?
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.
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