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-   -   CFX-Net Head Gain Calculation (https://www.cfd-online.com/Forums/cfx/232791-cfx-net-head-gain-calculation.html)

fatih06 December 30, 2020 14:03

CFX-Net Head Gain Calculation
 
Hello,

I am currently designing a pump that is from CFTurbo. To analyze it I am using CFX but when I get results in the expression tab I cannot see the net head gain.
So I decided to create my own expression but I failed.
This my expression
(massFlowAve(Total Pressure)@volute outlet-massFlowAve(Total Pressure)@R1 Inlet)/(1050*9.81)
So how can I achieve to define it?
Or is there any solution it to solve automatically?

Thank you.

Gert-Jan December 30, 2020 16:59

Why do you think it failed? Did you get an error or warning?

fatih06 December 30, 2020 17:15

Quote:

Originally Posted by Gert-Jan (Post 792011)
Why do you think it failed? Did you get an error or warning?

for example increasing the mass flow rate should result in decreasing the net head gained.
In the parametric study I chose 5 design points in 3 of 5 trend is like that but after 6L/min it suddenly increases and continue like that

Gert-Jan December 31, 2020 04:34

It is difficult to say what went wrong. It could be anything. It depends a lot on how you have setup your case.
Are you convinced it has converged? Do you monitor this equation during the solving process?


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