The Aircraft Noise Simulation Working Group (ANSWr) – V2 Aircraft Results

Abstract

A joint research activity of DLR, NASA and ONERA in the field of aircraft noise simulation is described. The Aircraft Noise Simulation Working Group (ANSWr) has been established to compare simulation tools, establish guidelines for noise prediction, assess uncertainties associated with the simulation, and establish a common knowledge in the field. These goals have been accomplished by using two virtual aircraft as a benchmark: a conventional tube-and-wing configuration as a reference case, and the low noise DLR configuration, V-2. The benchmark setup and results for the reference aircraft are presented in a separate paper. The purpose of the present paper is to describe the benchmark test case dealing with the V-2, a high wing aircraft concept with engines mounted above the wing and fuselage junction. The noise associated with this configuration is greatly dependent on the acoustic shielding of the engines by the airframe. Consequently, the comparison of the computed results focuses on the acoustic shielding calculations as well as on the noise source components. Remarkably, all three prediction methods show a good agreement with discrepancies typically lower than 4 dB for overall aircraft noise metrics such as peak noise levels. However, at forward and aft angles the aircraft system noise predicted can begin to show much larger differences, up to 5-10 dB. Much of the differences at large angles can be attributed to the shielding predictions but can also be due to some significant differences between the three predictions of the airframe noise sources.