Evaluation of embedded windshield resonators to reduce cabin noise of a UAM concept aircraft

High cabin noise levels in UAM vehicles could affect passenger comfort and thus passenger acceptance of this class of aircraft. As windshields will likely comprise a large percentage of the surface area of a UAM aircraft fuselage, the objective of this work was to explore the feasibility of a noise reduction concept that utilizes the windshield area. The concept aims to increase interior absorption at targeted frequencies by assuming that a honeycomb-like array of interior facing acoustic resonators are embedded within multiple transparent layers that make up the front and side windshields. The vehicle considered was based on the NASA RVLT Lift+Cruise UAM concept, which has 7.2 m2 of front- and side-facing windshields. Statistical Energy Analysis was used to evaluate the noise reduction attributed to the inclusion of various resonator configurations. The predicted noise reduction was dependent on the resonator geometry, the quantity of resonators included, and the assumed baseline interior cabin absorption. Results from a variety of resonator configurations are shown and discussed. The optical feasibility of the concept is not discussed in this work.