Engineering What Is the Pressure After a Hydro Turbine?

AI Thread Summary
The discussion centers on the pressure conditions after a hydro turbine, particularly when water discharges into the atmosphere versus a river. If the discharge occurs into 'clean' air, the pressure is assumed to be atmospheric pressure. However, if the discharge is submerged in a river, the pressure difference is influenced by the water levels of both the reservoir and the river. The configuration of the discharge point, whether submerged or above the river, significantly affects the pressure dynamics. Ultimately, understanding these configurations is crucial for optimizing energy storage systems in hydroelectric projects.
Pim_Verwoerd
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Homework Statement
Pressure loss due to turbine
Relevant Equations
P = Q * dP. Bernoulli
For an engineering project we have to make an energy storage system. We thought of something like a hydro dam. We were having a discussion about the pressure after the turbine in the hydro dam. The water immediately flows into the atmosphere ( so it falls down into a lake ). Can we then safely assume that the pressure over there is the atmospheric pressure? Or is there a different pressure field because of the turbine?
 
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I think it depends on the actual configuration. Does it have a submerged tailrace? Then not Patm.

440px-Hydroelectric_dam.svg.png
 
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gmax137 said:
I think it depends on the actual configuration. Does it have a submerged tailrace? Then not Patm.
That's interesting. Why would you discharge below the surface of the river? It seems like you'd want to maximize the pressure drop across the turnbine...
 
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gmax137 said:
I think it depends on the actual configuration. Does it have a submerged tailrace? Then not Patm.

View attachment 289165
No it doesn't have a submerged tailrace. The water that comes out of the turbine comes out into 'clean' air.
 
Pim_Verwoerd said:
No it doesn't have a submerged tailrace. The water that comes out of the turbine comes out into 'clean' air.
Then the pressure (in the clean air) is atmospheric. It can't be anything else.
 
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berkeman said:
That's interesting. Why would you discharge below the surface of the river? It seems like you'd want to maximize the pressure drop across the turnbine...
If the discharge is in the river then the pressure difference would be the difference between the reservoir water level and the river water level.

The head increase from a lower discharge is offset by the river water above the discharge.

If the discharge is above the river, the pressure difference is the difference between the reservoir water level and the discharge level.
 
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