After two years of Research and Development, Whale Tail Systems (WTS) has developed a cycloidal driven foil propulsor called Whale Tail Wheel ®.

The Whale Tail Wheel ® system can best be described as two wheels with a number of horizontal foils in between. It works by two forms of rotation. The wheels themselves, and the individual foils. As the wheels go through their cycles, the foils also rotate to achieve the optimum angle of incidence to the incoming flow of water.
MARIN contributed to the project with consultancy, computational modeling and scale model tests. MARIN’s Trials and Monitoring Group fitted one of the carbon-epoxy composite foils with strain gauges, data logger and battery pack.

The measurements included thrust, shaft torque and rpm, and amps from the servo engines driving the main wheel and those adjusting the foil angles. Open water tests with a Whale Tail Wheel ® prototype were conducted last summer (1998). These tests were aimed at the loads experienced by the foils, optimization of the foil angle as a function of the wheel angle, and the overall efficiency of the system. An inland waterway vessel is currently being equipped with a complete aft body to accommodate the Whale Tail Wheel ®, with a diameter of 1.50 meters and a width of 4.50 meters. Early in 1999 the converted vessel will start tests. Its performance will be quantified by the installed monitoring system.
More information: MARIN