Investigation of a Loose-Webbed Paddle Surface Impulse Propulsor

摘要

The purpose of this investigation was twofold. The first goal was to develop an understanding of the flow behavior and interaction with the blades of a paddlewheel type Surface Impulse Propulsion (SIP) system operating over a water surface. The second goal was to experimentally evaluate the effect of interblade webbing and wheel internal pressure on the thrust performance of a webbed SIP system. A series of configurations of forward speed, wheel rpm, blade immersion depth, web length, and internal wheel pressure were tested. Application of the webbing material significantly improved thrust production. Two critical parameters were the ratio of web length to blade tip to tip distance and internal system pressure. Both influenced the losses common to such a system, water entrainment at blade exit and air entrainment in the blade cavities at blade entry. Improvements of as much as 600% were seen in thrust coefficient for the best case, and significant performance improvement was noted over a wide range of parameters.