Active Acoustic Attenuation for Payload Fairings

CSA Engineering, Inc. and its team members McDonnell Douglas Aerospace and Professor Harley Cudney of Virginia Tech, propose the development of an active structural-acoustic control system for acoustic disturbance attenuation in composite payload fairings. The innovation is the use of piezoceramic actuators and structural sensors to cancel low frequency acoustic disturbances. Acoustic disturbances below 500 Hz are problematic in composite fairings due to the reduced weight-to-area ratio of composite material. Passive treatments, such as acoustic blankets and added mass, have limited effectiveness at low frequencies and significantly increase the weight and cost. The Phase I research will examine the feasibility of active structural acoustic control for payload fairings and estimate the weight, cost, performance, and power required for active acoustic control of the 40" diameter MSLS fairing. Active control concepts will be compared on a vibroacoustic model of the MSLS fairing. Passive designs will also be studied as a baseline for comparing the active techniques. A proof-of-concept experiment option task is included to demonstrate the feasibility of the active control concept. The anticipated Phase I results are sensor, actuator, and control configuration for active acoustic attenuation in the MSLS payload fairing. Benefits: The Phase I concept will be fully developed in Phase II and applied to the attenuation of acoustic disturbances in the MSLS fairing. The commercial development of active acoustic enclosures for semiconductor fabrication and inspection will be pursued.|