Open Water Performance of a Feathering Propeller

Abstract

In recent years, a number of propeller designs have been developed that aim to reduce the resistive characteristics of sailboat propellers when not in use. One of the more common of these designs is the feathering-blade propeller. Feathering propellers accomplish this decrease in resistance by rotating each blade to a pitch of 90 degrees, parallel to the flow of water over the blade. While the changes in blade geometry as a result of this design affect underway performance, there has been extremely limited empirical testing with regard to the power performance characteristics of these propellers. For this paper, performance comparisons were carried out between a two-blade, 12-inch diameter feathering propeller and standard Wageningen B-Series propeller data in an effort to quantify the difference in propulsive efficiency. These tests included a series of open-water propeller tests conducted in Webb Institute’s Robinson Taylor Model Basin and a series of ship standardization trials conducted aboard a Tripp 30 Sail Boat for a number of pitch-to-diameter ratios.