No convergence when PRESTO scheme is employ in water turbine modeling
 

Hello All:

I am simulating a water turbine with structured mesh for all domains. I noticed that when PRESTO scheme is employed the solution will not converge especially the momentum where its residual goes to very high values.

My second concern is that, when using single reference frame, the torque I got is higher than the experimental one: at some rotational speed it is twice and higher rotational speed it may reach one order of magnitude.

Thanks
Aziz