Experimental and theoretical study of propeller spinner/shank interference

A fundamental investigation into the aerodynamic interference associated with propeller spinner and shank regions has been conducted. The research program involved a theoretical assessment of solutions previously proposed, followed by a systematic experimental study to supplement the existing data base. As a result, a refined computational procedure has been established for prediction of interference effects in terms of either interference drag or propeller thrust and torque coefficients. These quantities have been examined with attention to engineering parameters such as spinner finess ratio, blade shank form, and number of blades. Also, cascade effects and spinner/shank juncture interference have been semi-empirically modeled using existing theories and placed into a compatible form with an existing propeller performance code.