Active Acoustic Liners enabled by Shape Memory Alloy Technology
Publication Type:
Conference
Authors:
Co-Authors:
Kreitzman, J.R., Calkins, F., Nicholson, D., and Lafranchi, A.
Year Published:
2020
Abstract:
Shorter engine inlets and more compact nacelles are being considered to reduce weight and drag of future commercial airplanes. Such designs may have significantly less area for acoustic treatment. Coupled with engine designs with lower blade passage frequencies and anticipated further stringency for airplane noise certification, the need arises for acoustic liner designs capable of a broad range of attenuation frequencies. With this in mind, a collaboration between Boeing, NASA and Florida State University was formed to develop active acoustic liner technologies to optimize acoustic performance and reduce drag during various stages of flight. One such concept is an active acoustic liner facesheet utilizing shape memory alloy (SMA) technology. A three layer facesheet with an actuated middle layer allows for the facesheet perforation to be sealed when noise attenuation is not required, thereby potentially reducing inlet and aft fan surface drag. This concept also allows for acoustic liner optimization in flight through altering the middle facesheet layer position, allowing for different size perforations to be achieved. This type of acoustic design has been explored in the past for the beneficial acoustic characteristics described above. However, up to this point, there have been limited efforts to develop methods to actuate, manufacture and integrate these designs in practice. This paper highlights the design, fabrication, test, and resulting analysis of the SMA facesheet development process. It will also discuss the successes, challenges, and potential future of active acoustic liner technology. Finally, preliminary impedance data will be shown that illustrates a potential design space for this active liner system.
Conference Name:
AIAA AVIATION 2020 FORUM
Conference Location:
Virtual Event
Other Numbers:
AIAA Paper 2020-2553
Refereed Designation:
Date Published:
6/8/2020