recomendations for impellor inlet conditions
 

hi,

this is a general question relating a little more to general impellor design in a water irrigation scheme. We have a pump that is cavitating and have performed CFD in intake structure and calculated levels of flow swirl and turbulent intensity at the entrance to the pump.

We were hoping the manufactor would be able to provide us with some indication on if the levels observed are excessive or not but they have not been able to make any comment.

The pumps move 2.1 m3/s of water, the NPSH available has a safety factor of 1.3 over the required limit.

My question is does anyone have any idea if any general guidlines exist to help provide some limit of turbulent intensity at the intake of pump of this type?