Influence of rotor phasing on quadrotor noise

Abstract

The report is a study of noise generated by different quadrotor configurations depending on the rotor spacing and phasing. The acoustics carpets below the quadrotors are compared between tool chains including a mid-fidelity code and a high-fidelity solver, validated with measurement data. The results show that the diamond configuration with a tip-to-tip phasing is the quietest of analyzed variants, while the same configuration with reduced spacing and orthogonal phasing generates the highest SPL levels. From the square configurations, the square bearhug configuration with orthogonal phasing and increased rotor spacing is favorable in terms of acoustic characteristics. The acoustic interference between the rotors is a decisive mechanism in reduction of OASPL levels, rather than the mitigation of aerodynamic interactions.