Noise Reduction of Main Landing Gear of High-Lift Common Research Model

This paper highlights the effectiveness of noise-reduction devices on an 8%-scale, detailed four-wheel main landing gear model based on NASA’s design for the high-lift common research model (CRM-HL). This project is a collaborative effort between JAXA and Safran Landing Systems to reduce landing gear noise from commercial airplanes. The study investigates three types of noise-reduction devices that utilize porous plates: a truck beam porous plate with forward-bent edges, main strut porous plates, and brace porous plates. Although the main landing gear is a generic research model, the noise-reduction devices were designed to be structurally practical while considering the landing gear’s retractability and clearance margins. Far-field noise measurements were conducted at a freestream wind speed of 80 m/s on the stand-alone main landing gear model, both with and without noise-reduction devices. Additionally, computational simulations were performed to validate results against experimental data and to enhance understanding of the noise-reduction effects by visualizing flowfields. The noise-reduction configuration using the three devices significantly reduced noise by over 2 dB at all four microphone locations in a wind-tunnel test.