D4.1.6 Splitter plate aeroacoustic test report D4.1.7 Deceleration flow plate noise report

Abstract

This report presents a brief overview on the results obtained during the scale model landing gear test in the Acoustic Wind Tunnel Braunschweig1. Noise tests were conducted on different 4-wheel landing gear configurations with (i) deceleration plates and (ii) splitter plates. The results presented in this report indicate that deceleration plates when attached between the rear wheels downstream of the axle tend to reduce the farfield radiated landing gear noise by up to 4 dB. In the course of this test best results were obtained by means of an inner wheel deceleration plate in combination with a short lower leg deceleration plate. The installation of an upper leg deceleration plate was not effective in terms of noise reduction. For splitter plates when applied to several gear components different results were obtained. While the wheel splitter plates tend to increase noise levels nearly no effect was measured for splitter plates located at the main strut and the side stay. A slight noise reduction of about 1 dB was documented for both the torque link and the drag stay splitter plate configuration. The noise test on a 2-wheel landing gear again proved the beneficial effect of an inner wheel deceleration plate on farfield radiated noise.