Auralization of aircraft flyovers with turbulence-induced coherence loss in ground effect

Abstract

Residents around airports are impacted by noise produced by civil aircraft operations. With the aim of reducing the negative effects of noise, new low-noise aircraft concepts and flight procedures are being developed. The design processes and the assessments of design variants can be supported by auralization of virtual flyovers. The plausibility of auralized aircraft is increased by considering the effects of atmospheric turbulence on sound propagation. This paper presents a simple approach to include turbulence-induced coherence loss in ground effect. Compared to earlier approaches, the proposed model is closer to the physical mechanisms. It is based on the von Kármán turbulence spectrum and a time-variant partial decorrelation filter. The application of the model to jet aircraft flyovers revealed audible improvements by reducing unnatural flanging. The proposed model increases the accuracy and plausibility of aircraft flyover auralizations. It will thus be applied in the perception-based evaluation of future aircraft concepts.