Lattice Boltzmann Simulation Of Transonic Rotor Aerodynamics And Acoustics

Abstract

This paper presents the validation and assessment of rotorcraft High-Speed Impulsive (HSI) noise prediction using a high-fidelity Lattice Boltzmann / Very Large Eddy Simulation (LB/VLES) transonic solver, SIMULIA PowerFLOW®, coupled with the time-domain Ffowcs-Williams Hawkings (FW-H) solver, SIMULIA PowerACOUSTICS®. A benchmark transonic rotor case featuring high-subsonic and transonic tip speeds is used for the analysis. Flow predictions reveal the formation of localized supersonic pockets on the blade surface and the development of a shock spiral in the rotor plane. As the tip speed increases, the solver accurately captures the associated shock de-localization characteristic of transonic rotors. The resulting HSI noise-driven by these shock dynamics-is well predicted by the computational framework, demonstrating good agreement with experimental data.