Many people who live near airports constantly complain about the noise caused by airplanes flying around. Researchers at NASA’s Langley Research Center in Hampton, Virginia, completed a round of testing in late January 2021 to design a new experimental wing aimed at making the aircraft quieter. Improvements included a new flagship wing specifically designed to reduce noise.
Making planes quieter is the primary goal of Container Advanced Air Transport Technology (AATT) project. The project supports a joint experimental and computational effort to understand and mitigate noise associated with a specific aircraft wing. Program managers say mitigating specific noise emissions directly benefits residents who live near airports and has financial benefits for aircraft operators because landing fees at many airports are related to noise caused by aircraft using the runway.
NASA reports that sources of non-propelled aircraft noise include high-lift devices such as the front slats and trailing edge racks that form part of an aircraft’s wing. A prominent source of airframe noise during an aircraft approach was identified through model scale tests using flight noise measurements and numerical simulations.
NASA built a 10 percent scale version of the high-lift combined search model to evaluate various aircraft improvements, including low-noise chipsets. Tests were conducted in January using a NASA 14 × 22 subsonic tunnel to demonstrate the effectiveness of chip noise reduction concepts made with shape alloys.
The researchers chose shape-memory alloys because they can undergo the large deformations needed for devices to store when the chip is retracted. The new low-noise chips have been developed using small-scale testing and computation techniques designed to evaluate aerodynamic, structural and acoustic performance. The goal of the program is to develop technology to allow the aircraft industry to easily adopt it. The next round of testing the design of the new wing will take place this spring.