A scale model a horizontal axis marine current turbine was tested at the circulating water channel facility at QinetiQ in Hampshire. The model was scaled such that the ratios of the rotor diameter/water depth and the blade tip speed/inflow speed were equal to that of a full scale device. The three bladed rotor depicted was connected to a generator situated above the water line via a right angle gearbox. A bank of variable resistors connected to the generator as shown which allowed the rotational frequency of the rotor to be altered during operation.
The testing programme included ascertaining the power output for varying flow speeds, rotor speeds, blade pitch angles and rotor yaw angles. This work will enable the performance of a horizontal axis rotor to be characterised for underwater conditions and compared with conventional theory that does not fully cover all the conditions that were present in the testing or for full scale turbine. The characteristics of the turbine wake were also ascertained for several different operational conditions. Wake velocity measurements were taken at many locations downstream of the model turbine.