CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   STAR-CCM+ (http://www.cfd-online.com/Forums/star-ccm/)
-   -   Pump characteristic / performance curve (http://www.cfd-online.com/Forums/star-ccm/95800-pump-characteristic-performance-curve.html)

husker January 3, 2012 11:45

Pump characteristic / performance curve
 
Hi all,

I am trying to build the performance curve of a centrifugal pump.
I do know the design point (mass flow rate and rpm).

However I need the performance curve (mass flow rate vs. head).
I tried the followings:

1) I set 40, 60, 80, 140, 160, 180 percent of design mass flow rate at the inlet and monitored the output pressure. Outlet BC was pressure outlet.

2) I tried fixing several head values by setting different pressure values at the inlet and outlet at a constant rpm. Inlet and outlet BCs are pressure outlet.

Finally I monitored pressures and velocities and none of my all simulations converged.

Any ideas about what is wrong? Or any recommendations about how to build the performance curve?

Regards

Ladnam January 15, 2012 08:54

If you give more information about your model it is easier for people to answer. Maybe your underrelaxation factors are too high.

abdul099 February 18, 2012 09:10

Quote:

Originally Posted by husker (Post 337685)
... and none of my all simulations converged.

How do you judge convergence?

husker February 20, 2012 04:42

Quote:

Originally Posted by husker (Post 337685)
Hi all,

...
2) I tried fixing several head values by setting different pressure values at the inlet and outlet at a constant rpm. Inlet and outlet BCs are pressure outlet.

Finally I monitored pressures and velocities and none of my all simulations converged.

...
Regards

My solutions converged with Mass Flow Inlet & Pressure Outlet BCs. But I can't simulate with two pressure boundaries. I set static pressure at the outlet to zero and fix total pressure at the inlet. Do you have any ideas?

Do you have any ideas?

husker February 20, 2012 04:46

By the way, I set total pressure by using Stagnation Inlet BC.


All times are GMT -4. The time now is 04:52.