Experimental investigation of the four-wheel landing gear noise in large-scale configurations

Landing gear is an important contributor to the total noise emission of an aircraft, particularly at take-o and approach. This paper reports an experimental study on the noise production of a large-scale landing gear model in different configurations, conducted in the FL-17 5.5m 4m aeroacoustic wind tunnel in China Aerodynamics Research and Development Center. A high resolution 135-microphone array was used to perform the noise localization based on beamforming algorithm, and a series of far-field microphones were installed to characterize its acoustic performance. Configurations of the model include different angles of attack, different cylinder heights, different yaw angles, etc. First of all, a semi-empirical model to predict the landing gear noise was validated using the measurement data. It was found that in terms of the trend the model can well make the prediction, therefore it can be used to do the preliminary acoustic performance in the practical engineering. Then, from the measurement, effects of those parameters on the acoustic performance of a large-scale noise landing gear model was assessed, and conclusions on their contributions to the noise landing gear was drawn. Findings of this paper offer a reference to the acoustic design of a real noise landing gear.