Hover performance prediction using full-potential method and comparison with experiments

A computational and experimental effort to investigate the flow around roto r blades in hover is presented. The experimental analysis of the flowfield in the immediate vicinity of the blade is supported by laser velocimetry (L V) performed on the three-dimensional velocity field around the blade secti on and in its near wake. A specific LV data processing method based on the momentum equation applied around a blade section has been developed to iden tify the contribution of the induced-drag component to the total sectional drag coefficient. From the computational approach, some improvements to a v ortex embedding Full-potential method are checked by direct comparisons wit h test data. Comparisons are performed for overall rotor airloads (thrust a nd torque coefficients), local sectional coefficients (lift and drag contri butions), and flowfield characteristics, including the tip vortex path and the spanwise circulation distribution.