Active Structural Acoustic Control of a Launch Vehicle Fairing Using Monolithic Piezoceramic Actuators

Abstract

This study investigated the feasibility of using active structural acoustic control with monolithic piezoceramic actuators to reduce the low frequency noise transmission through rocket fairings during launch. Closed-loop simulation results are presented using a fully coupled structural acoustic model of a lightly damped composite fairing structure with integrated piezoceramic actuators. Constraints were placed on controller mass and maximum allowable actuator voltage in order to provide a baseline of reasonable expected performance. Realistic disturbance levels were used in the simulations, and two disturbance cases were considered with significantly different spectral characteristics. Simulations were conducted to compare the effects of actuator thickness, covered surface area, and maximum actuator voltage on controller performance and energy requirements. Linear Quadratic Regulator control laws were computed assuming full-state feedback using three design approaches. The results provide significant insight into the noise transmission problem and to the physical dynamics of the control approach. The best-case reduction in the spatially averaged interior acoustic response was determined to be approximately 2.5 dB over the 0-300 Hz bandwidth.

Active structural acoustic control of composite fairings using single-crystal piezoelectric actuators

“…These results were consistent with related active control studies on a cylinder using piezoelectrics conducted by Niezrecki and Cudney [7]. A conclusion of the studies by Griffin et al [4,5] was that the performance of passive tuned-massdampers attached to the fairing wall was nearly equivalent to active control approaches, without the complexity, cost, and robustness issues of an active control system.…”

“…Bingham et al [3] provide a good discussion on the use of various active control methods for acoustic radiation reduction of composite plates. Griffin et al [4,5] developed and used fully coupled structuralacoustic models of a small composite fairing to simulate and baseline different active control approaches for fairing noise mitigation. The goal of these simulations was to predict bestcase performance of active structural-acoustic control over the 0-300 Hz bandwidth, given realistic limits on controller mass and control effort.…”

“…Recent advances in actuator technology have prompted the re-examination of active structural-acoustic control using piezoelectrics [8][9][10][11]. In the works by Griffin et al [4,5], the performance of the actuators was limited by the maximum voltage (i.e. control effort) that could be applied to the actuators and the coupling between the actuators and the structure.…”

Active structural–acoustic control of laminated cylindrical panels using smart damping treatment

“…Their research brought out the important implications [20] that the curvature of a panel substantially affects the dynamics of the panel, the integrations of the transducers and the bandwidth required for structural-acoustic control. Recently, Lane et al [22] studied the active structural-acoustic control of a launch vehicle fairing using monolithic piezoceramic actuators. As far as the application of ACLD treatment is concerned, Ro and Baz [23] first demonstrated experimentally and numerically that the sound radiated from an aluminum plate coupled to an acoustic cavity can be effectively controlled by the use of patches of ACLD treatment.…”

Chamber Core Structures for Fairing Acoustic Mitigation

“…In laboratory experiments, these approaches typically provided 6 dB of narrowband attenuation, and 2-3 dB broadband attenuation. Active control methods were also investigated both experimentally and in numerical studies [4][5][6]. The active control methods investigated include active structuralacoustic control (simulated optimal feedback control with piezoelectric actuators/sensors on a composite fairing), active acoustic damping with distributed sensor/actuator arrays (experimentally), and adaptive feedforward structural-acoustic control using distributed active vibration absorbers (experimentally).…”