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Active Control of Fan Noise-Feasibility Study. Volume 2: Canceling Noise Source-Design of an Acoustic Plate Radiator Using Piezoceramic ActuatorsThe feasibility of using acoustic plate radiators powered by piezoceramic thin sheets as canceling sources for active control of aircraft engine fan noise is demonstrated. Analytical and numerical models of actuated beams and plates are developed and validated. An optimization study is performed to identify the optimum combination of design parameters that maximizes the plate volume velocity for a given resonance frequency. Fifteen plates with various plate and actuator sizes, thicknesses, and bonding layers were fabricated and tested using results from the optimization study. A maximum equivalent piston displacement of 0.39 mm was achieved with the optimized plate samples tested with only one actuator powered, corresponding to a plate deflection at the center of over 1 millimeter. This is very close to the deflection required for a full size engine application and represents a 160-fold improvement over previous work. Experimental results further show that performance is limited by the critical stress of the piezoceramic actuator and bonding layer rather than by the maximum moment available from the actuator. Design enhancements are described in detail that will lead to a flight-worthy acoustic plate radiator by minimizing actuator tensile stresses and reducing nonlinear effects. Finally, several adaptive tuning methods designed to increase the bandwidth of acoustic plate radiators are analyzed including passive, active, and semi-active approaches. The back chamber pressurization and volume variation methods are investigated experimentally and shown to be simple and effective ways to obtain substantial control over the resonance frequency of a plate radiator. This study shows that piezoceramic-based plate radiators can be a viable acoustic source for active control of aircraft engine fan noise.
Document ID
19960003376
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Pla, F. G.
(General Electric Co. Cincinnati, OH, United States)
Rajiyah, H.
(General Electric Co. Cincinnati, OH, United States)
Date Acquired
September 6, 2013
Publication Date
March 1, 1995
Subject Category
Acoustics
Report/Patent Number
NAS 1.26:195440
E-9475
NASA-CR-195440
Accession Number
96N13385
Funding Number(s)
PROJECT: RTOP 538-03-11
CONTRACT_GRANT: NAS3-26617
Distribution Limits
Public
Copyright
Public Use Permitted.
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