Aerodynamic Performance of Propellers Suitable for Unmanned Aircraft (UMAS)

摘要

The aerodynamic performance of 13 cheap fixed-pitch 0.512 m diameter pusher-propellers suitable for powering unmanned aircraft for low speed missions (i.e., less than 50 m/sec) was investigated. Ten of them were twin-bladed and three of them had four blades. Thrust and torque at rotational speeds between 3000 and 9000 rpm in the 1.5 m acoustic tunnel at airspeeds from 10 to 50 m/sec were measured. As expected, propellers with coarser blade settings require more power and produce more thrust than those with finer pitch, and peak efficiency is delayed to higher values of the advance ratio (J). The peak efficiency is between 70 and 80 percent measured efficiency over the normal operating range (J=0.4 to 0.6) is 80 to 85 percent of the ideal efficiency, for a propeller of a different design performance is degraded by a further 10 percent.