Vertical axis wind turbine wake velocity measurements and comparison with analysis

Mean velocity measurements were performed in the wake behind a Darrieus Turbine. In this experiment the turbine was towed through a tank filled with water. Reynolds' number scaling was used to relate the operation in water to that in air. The results were compared with predictions from the momentum and vortex models developed by previous workers. In addition, some data from a full scale rotor obtained by other workers are presented and compared with analytical results.