Performance of an integrated water turbine PM generator

The experimental performance of a small 250 mm diameter novel water turbine PM generator, originally designed as a tip driven integrated thruster, was studied in a towing tank. The PM rotor of the generator forms a ring around the tips of the turbine blades. The stator is integrated into the turbine ducting. The test results show that the alternator produces about 50 W of power in a stream with a flow speed of 2 m/s at an efficiency of 35%. This performance is slightly better than that of a commercially available device. A set of nondimensional curves derived from the test results are also presented in the paper. These curves can be used to predict the performance of different sizes of this type of generator for different stream speeds. The paper discusses the potential of this type of generator in the light of these results.