Cyclorotor Noise Characterization Using High-Fidelity Aeroacoustic Simulations

Abstract

Cyclorotors are a unique propulsion type offering rapid, 360° thrust vectoring, which is especially attractive for urban air mobility (UAM) applications. For UAM, noise is a key consideration. However, there is currently little research into cyclorotor noise. This study presents the first high-fidelity aeroacoustic simulations of cyclorotors, using the lattice Boltzmann method with very large eddy simulation (LBM-VLES). A detailed investigation of the noise-generating mechanisms is conducted. Furthermore, a comparison is made with a conventional propeller of equivalent dimensions that provides the same thrust. The results show that cyclorotor noise is dominated by unsteady loading associated with blade-vortex interactions, which offsets the acoustic benefit of the lower blade velocity. In our results, the cyclorotor is not inherently quieter than a conventional propeller operating at similar thrust under isolated conditions.