Measurement of instantaneous pressure distributions and blade forces on an airfoil undergoing cycloidal motion

Instantaneous pressure distributions and transient blade loads which are typical of those occurring on a Carrieus wind turbine were recorded at three tip-to-windspeed ratios. The turbine was simplified to that of a single air-foil moving along a cycloidal trajectory into otherwise motionless water. The use of water as a working fluid facilitated the ability to make low- frequency measurements while operating at appropriate blade Reynolds numbers- A comparison between the blade force data and the forces predicted by an existing analytical model was made. In addition, the instantaneous pressure distributions were analyzed in an investigation of the dynamic stall phenomenon.