NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Prop-walk.
From: Jared Sherman
Date: 2003 Apr 22, 22:20 -0400
From: Jared Sherman
Date: 2003 Apr 22, 22:20 -0400
Peter-Not right at all. Cavitation is, specifically, that phenomena where water literally BOILS in the relative low pressure zone at the trailing edge of the screw. Since the water pressure is lower closer to the surface, it is easier for air to boil out in the water closer to the surface. Take a big enough prop, put enough horsepower behind it, and the right shape to the edge. and you can make it cavitate at any depth. Reduce the horsepower, reduce the prop speed, and you reduce the pressure differential and the boiling stops. Another one explained in the engineering texts.