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-   -   Calculation of power in CFD Post for a radial turbine (https://www.cfd-online.com/Forums/cfx/188419-calculation-power-cfd-post-radial-turbine.html)

AntonZ May 29, 2017 23:10

Calculation of power in CFD Post for a radial turbine
 
Hi all,
I am calculating a radial turbine.
Two methods for that are
1) torque@Blade * omega (built in Ansys-macro)

2) through enthalpy
massFlowInt(Total Enthalpy in Stn Frame)@ BeforeWheel * NumOfSegments1 - massFlowInt(Total Enthalpy in Stn Frame)@ BehindWheel * NumOfSegments2

For axial compressors and turbines both formulas give coincident results. But for radial - no.

At the moment I get like 2 times difference between them and I cant figure out why?
In my case I have a Blade and Splitter as one surface defined in CFX and 8+8 Blades alltogether.
It looks like 1-st formula gives more real value (10 kW vs 20 kW for Enthalpy-Power).
Are there other things I have to keep in mind when calculating power for radial turbines?
Is there other way to calculate power to compare it with upper two?

Thanks.


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