Multiphase simulation in FLUENT for rotating equipment
 

I am trying to model an predict the NPSHR in centrifugal pumps I wonder that is there any special model or way of defining boundaries for reaching some reasonable results.

There is no special way for this case. Just make sure that the grid resolution is fine enough to provide decent pressure profiles. The difference between the inlet pressure and the lowest pressure in the domain, in combination with knowing the vapour pressure of the liquid, should be sufficient to define the NPSHR.

Thanks dear David
 

I wonder if there is a model for visualization of vapor which are produced in cavitation phenomena...
Thanks for your answers

There is a built in cavitation model within Fluent that you can use. You need to run a multiphase simulation but it will show vapour generation should you go below the vapour pressure.

Thanks dear David
 

Yes you are right, but I have tried some mutliphase models the run doesn't start...
If it is possible for you help me about the settings for simulating cavitation visualization in FLUENT for Centrifugal Pumps.

Please refer to http://www.docin.com/p-392460303.html

Thanks David
 

It is vary nice & helpful tutorial...
I am going to study and let you know the results.

Hi!
If you want to evaluate NPSHr, why you want to simulate cavitation?
Pump must avoid cavitation during operation and so NPSHr is well above this limits.
I think you should run single phase simulations: if you see absolute pressure <= vapor pressure, it's not realistic (in your case): this means that in these areas cavitation occurs, so you need to change boundary conditions to avoid it.
Moreover, simulation of cavitation si not straightforward: all the models are "incompleted", as the terms in the source equations don't take into account all the members of the Rayleight equation, and this, in some cases, lead to converged solutions, but irrealistic results.
Custom cavitation models can be implemented through udfs, but they require fine tuning with experimental data.

Daniele