Experimental Investigation of Quadrotor Aerodynamics with Computational Cross-Validation

Abstract

The influence of interactional effects on quadrotor performance in forward flight was evaluated taking into account square and diamond configurations, forward and backward tilt angles and a range of hub spacings including over lapping blades. The analysis was based on the wind-tunnel measurements and simulations from five computational methods with different fidelity levels. The outcome indicates that the efficiency of a diamond configuration improves in comparison with isolated rotors for non-overlapping rotor spacings, while the interactions in square alignments are detrimental for all analysed test cases. The computational results showed good agreement with the measurement data for the forward rotor plane tilt, however for the increased rotor-wake interactions at a backward tilt angle the spread between the calculated values, especially for torque, could be observed with the general trends maintained. The study proves the diamond configuration with 1.2 D rotor spacing and tip-to-tip rotor phasing to be most favourable in analysed conditions in terms of both aerodynamic performance and acoustic signature.