Investigation of Ground Effects and Atmospheric Conditions on Noise Perception from Small Aircraft Technologies

Abstract

Since urban air mobilities are used for low-altitude operations over populated areas, their realization depends on social acceptance, which is mainly influenced by noise on the ground. Besides psycho-acoustic factors, the perception of noise is affected by ground and atmospheric conditions. Existing aircraft noise prediction models do not consider these effects. Publications have shown that the deviation between simulations and measurements increases with growing lateral distance from the noise source. For an accurate assessment of noise perception from low-flying small aircraft, it is important to include the impact of ground and atmosphere. By applying a particle-based propagation model, these effects are investigated for two different flight altitudes. Simulation results show that downwind the lower-flying airplane is perceived −4.9 dB quieter, when complex ground and real weather conditions are included. Upwind, a level increase of +3.6dB is observed. Weatherdependent optimization of flight paths can contribute to minimizing the perception of noise on communities.