Investigation of noise characteristics of jet noise from high- BPR turbofan engines in model-scale

摘要

Two experiments have been performed to investigate the characteristics of jet noise from aircraft powered by modern turbofan engines: the first experiment was carried out in the anechoic chamber of Beihang University, China in 2016 and the second one was carried out in the anechoic wind tunnel of ONERA, CEPRA 19 in the winter of 2017. During the first experiment, various dual-stream nozzle exhaust geometries were tested to obtain a comprehensive database of jet noise from dual-stream exhaust geometries for static conditions. Two area ratios (an area of the secondary nozzle over an area of the primary nozzle), five and seven are considered for the investigation of jet noise from both current generation and next-generation aircraft. The second campaign also handled the two area ratios using larger-scale models of nozzles. The second one covered the noise in flight conditions as well as in static conditions with microphone arrays at two different azimuthal angles. It is expected that the effects of the following parametric variations will be presented in this paper using the acoustic data acquired from two experiments with the isolated configurations: (1) impact of area ratio; (2) effect of nozzle-operating conditions; (3) impact of chevron nozzle configurations for noise mitigation; and (4) flight effect.