Aeroacoustics research in Europe: The CEAS-ASC report on 2017 highlights, Contribution: Uncertainty assessment of a parametric aircraft system noise prediction

Abstract

Short review of DLR and TU Empa reserach activities toward uncertainty assessment of aircraft noise predictions. A new approach to assess uncertainties associated with the predicted noise levels was introduced in previous publications. The overall uncertainty is thereby comprised of input data, noise modelling, and sound propagation uncertainties. Obviously, each modeled noise source is associated with different input data and modelling uncertainties. According to the constantly changing noise source ranking along typical flight procedures, the overall uncertainty of the predicted ground noise level is highly variable. The new approach is applied to a DLR simulation process to establish a quality assessment and enable a reliable system noise prediction. It is demonstrated how the prediction results are affected by the underlying and prevailing uncertainty. Noise isocontour areas are subject to significant variations when uncertainties are introduced. Uncertainty analysis reveals that uncertainty associated with input data and propagation effects can even exceed the uncertainties of the noise source models when simulating conventional vehicles. The established uncertainty assessment can readily by applied to conventional tube-and-wing vehicles with turbofan engines.