Simulation of Landing and Take-Off Noise for Supersonic Transport Aircraft at a Conceptual Design Fidelity Level

Abstract

The German Aerospace Center has launched an internal project to assess the noise impact associated with supersonic transport aircraft during approach and departure. A dedicated simulation process is established to cover all relevant disciplines, i.e., aircraft and engine design, engine installation effects, flight simulation, and system noise prediction. The core of the simulation process is comprised of methods at the complexity and fidelity level of conceptual aircraft design, i.e., typical overall aircraft design methods and a semi-empirical approach for the noise modeling. Dedicated interfaces allow to process data from high fidelity simulation that will support or even replace initial low fidelity results in the long run. All of the results shown and discussed in this study are limited to the fidelity level of conceptual design. The application of the simulation process to the NASA 55t Supersonic Technology Concept Aeroplane, i.e., based on non-proprietary data for this vehicle, yields similar noise level predictions when compared to the published NASA results. This is used as an initial feasibility check of the new process and confirms the underlying methods and models. Such an initial verification of the process is understood as an essential step due to the lack of available noise data for supersonic transport aircraft in general. The advantageous effect of engine noise shielding on the resulting system noise is demonstrated based on predicted level time histories and certification noise levels. After this initial verification, the process is applied to evaluate a conceptual supersonic transport design based on a PhD thesis with two engines mounted under the wing, which is referred to as aircraft TWO. Full access to this vehicle’s design and performance data allows to investigate the influence of flight procedures on the resulting noise impact along approach and departure. These noise results are then assembled according to proposed Federal Aviation Agency regulations in their Notice of Proposed Rulemaking, e.g., speed limitations, for Supersonic transport noise certification and the regulations from Noise Chapters of the Annex 16 from the International Civil Aviation Organization in order to evaluate the resulting levels as a function of the flight procedure.

Conceptual Design of a Next Generation Supersonic Airliner for Low Noise and Emissions

“…The airframe noise prediction model is based on Fink's method [33]. With the aim of carrying out an engine noise shielding assessment during early design stages, a simple method is applied (Maekawa method) which predicts noise shielding effects based on wing-fuselage planform and engine locations [34].…”

A Simulation Framework for Aircraft Take-Off Considering Ground Effect Aerodynamics in Conceptual Design

“…Finally, Ref. [51] proposes a simulation process to assess the noise impact associated with a benchmark supersonic transport aircraft configuration during approach and departure. Although of high significance, the previous proposed methods are not generalizable for the utilization in conceptual aircraft design, as they rely on specific tuned datasets, or are developed for a specific case/condition, or are not capable to reproduce and assess generic aircraft configurations and their performance.…”

Jet Noise Prediction Benchmark for Landing and Takeoff Noise of Supersonic Aircraft

“…By allowing to takeoff at higher speeds one can avoid to fly in the envelope of reversed command which consequently reduces the required thrust and therefore the engine noise. The effectiveness of this advanced takeoff procedure for commercial supersonic business jets was recently investigated by NASA [11], JAXA [12] and DLR [13]. The advanced takeoff procedure has at least four degrees of freedom: 1) the percentage of thrust reduction, 2) the altitude at which PLR is initiated, 3) the allowed air speed and 4) the rate of thrust reduction.…”