Proposal Response for Non-Wearable and Off-Engine Jet Noise Reduction

Jet aircraft and engine noise present significant challenges for Naval operations, particularly during takeoff roll, carrier deck warmups, and engine testing in Hush Houses. These noise levels pose risks to Navy personnel, contributing to long-term hearing loss and reduced crew performance, while also generating community noise complaints that impact training and operations. As modern jet engines grow more powerful, passive noise control methods are reaching their limits, necessitating new approaches.This Phase I effort focuses on developing and testing an Active Noise Cancellation/Control (ANC) system to mitigate jet takeoff roll noise (JTRN) and carrier deck engine warmup noise. The proposed ANC system consists of an array of deployable large loudspeakers, reference microphones, error microphones, and a digital multi-channel feedforward controller. This system leverages technology and expertise developed by Harris Miller Miller & Hanson Inc. (HMMH) and Prof. Fuller of the National Institute of Aerospace/Virginia Tech, previously applied to commercial aircraft noise.The primary technical objectives for Phase I include obtaining representative noise signals of Navy jet operations, developing an analytical model to predict ANC attenuation performance, and optimizing system parameters to achieve a minimum 10 dBZ reduction at frequencies below 5 kHz. Full-scale field testing using recorded JTRN signals will validate the ANC model. Additional objectives in the Phase I Option phase include extending the ANC model to carrier deck warmups, determining power requirements for active sources, and conducting preliminary testing in a controlled environment.The Phase I Statement of Work includes:Identifying and analyzing representative jet noise signals from existing databases.Developing a simulation model to predict ANC effectiveness for JTRN mitigation.Simulating noise control performance for various ANC configurations.Conducting full-scale field testing of ANC for JTRN to validate predictions.Extending the ANC model to carrier deck operations and testing active noise cancellation in that context.Managing project progress through bi-weekly meetings, reporting, and final documentation.Successful Phase I execution will demonstrate the feasibility of ANC for Navy jet operations, validate modeling approaches, and inform ANC system design. Phase II will expand testing to a hot jet test facility and eventually to operational Navy aircraft at a suitable airfield. Future developments will explore advanced active sources, such as compressed air-based systems, and commercial applications in collaboration with leading manufacturers. This research has the potential to significantly reduce noise exposure for Navy personnel and surrounding communities while preserving operational effectiveness.