cavitation

[cprclr]

I think I know the answer to this question but I want to be sure, my GTS cavitates (does not hook up) until I get going a little then I have power. I just did a rebuild on the thrust bearing and misc. items. Now I do have an impeller that was brought back to service from damage and the pump has a fin with a 1" by 1" chunk out of it. Is the causing my cavitation at take off?

 

[JPX]

It's certainly not helping. Any disruption in the overall flow through the pump can induce some cavitation.

As the impeller builds up pressure against the venturi, the air that gathers around the rough spot (big wear ring clearance, dinged impeller, damaged vanes in the pump) compresses easier than water. Then the pressure exceeds some point where the caviation can be overcome by pure speed.

 

[seadoosnipe]

Flow direction.......

The stator (fin) is a stationary set of blades meant to redirect the flow of water to help counter the rotational torque of the impeller but more importantly, to increase water flow.

For every time flow direction is changed, there is a momentary increase in pressure from that change in flow............so, yes, this could certainly cause a loss of performance.....but not much. The biggest problem with a "chunk" gone will be the drag created from the disturbance created from deflection.