Computational Analysis of Rotor-Blown-Wing for Electric Rotorcraft Applications

This Paper examines the performance of a rotor-blown-wing in hover and forward flight conditions. Flow solutions were generated using Helios, with a delayed detached eddy simulation model. The configuration is based on one set of rotors/wing of a quadrotor biplane tail-sitter aircraft. Simulations were conducted to assess the effect of varying angle of attack, rotor revolutions per minute with rotor speed, and rotor diameter. Two configurations were examined, the rotor-blown-wing baseline with two 60.96 cm diameter rotors and the R³ configuration with four 30.48 cm diameter rotors. The smaller rotors were analyzed at the revolutions per minute corresponding to producing half the thrust of the rotor-blown-wing baseline rotor. The presence of the wing in hover resulted in the rotor-blown-wing baseline rotor operating at 1.9% lower power loading than the same rotor in isolation. In comparison, the R³ configuration reduced power loading by 13.6% compared to the isolated rotor. In forward flight (airplane mode), an increasing angle of attack was shown to increase thrust produced on the downstroke side of the rotor. Furthermore, the presence of the wing increases the thrust produced on the bottom half of the disk. Both the blown wings increase the L/D ratio from 3.2 for the isolated wing to 3.6 and 4.3 for the rotor-blown-wing baseline and R³ configurations, respectively.