Aerodynamic Performance of Distributed Electric Propulsion Wing Under Different Design and Operating Parameters

This study aims to experimentally and numerically investigate and compare the aerodynamic performance of two triple-propulsor leading-edge mounted Distributed Electric Propulsion (DEP) configuration. The experiments are conducted in the Wind Tunnel Facilities at the University of Bristol. Propeller performance is examined experimentally against their positions on the wing at different inflow speeds and wing angles of attack (AoA). Numerical Vortex Particle Method (VPM) simulations are carried out to compare with the experimental aerodynamic results, and provide an exploratory noise comparison between the configurations. The DEP configurations involved in the current work are three 12-inch (the 12-12-12 configuration) and three 15-inch (the 15-15-15 configuration) propellers. Aerodynamic measurements for the propellers and the overall wing are examined and analysed at inflow speeds of 10 and 20m/s. The 15-15-15 configuration is operating at lower propeller rotational speeds to match overall thrust to be the same as of the 12-12-12 configuration. The aerodynamic measurements indicate that mid propeller produces less thrust than adjacent propellers while having comparable torque, and this difference becomes more significant as propeller rotational speeds and wing AoA increase. For the 12-12-12 configuration, the propeller performance is less sensitive to the change of angle of attacks at 10m/s, whereas a noticeable increment in thrust is captured for the inboard propeller for the 15-15-15 configuration as AoA increases. Wing performance comparison indicates that the 15-15-15 wing has slight lift-to-drag ratio improvements at low angles of attack, whereas the 12-12-12 configuration is marginally more favourable at high angles of attack. Numerical simulations show good agreement on propeller thrust predictions, whereas torque predictions significantly vary across different positions on the wing. The noise results indicate that the 15-15-15 configuration has a lower tonal noise emission than the 12-12-12 configuration at 1st Blade Passing Frequency (BPF) when producing the same thrust on the wing.