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Robust Feedback Control of Flow Induced Structural Radiation of SoundA significant component of the interior noise of aircraft and automobiles is a result of turbulent boundary layer excitation of the vehicular structure. In this work, active robust feedback control of the noise due to this non-predictable excitation is investigated. Both an analytical model and experimental investigations are used to determine the characteristics of the flow induced structural sound radiation problem. The problem is shown to be broadband in nature with large system uncertainties associated with the various operating conditions. Furthermore the delay associated with sound propagation is shown to restrict the use of microphone feedback. The state of the art control methodologies, IL synthesis and adaptive feedback control, are evaluated and shown to have limited success for solving this problem. A robust frequency domain controller design methodology is developed for the problem of sound radiated from turbulent flow driven plates. The control design methodology uses frequency domain sequential loop shaping techniques. System uncertainty, sound pressure level reduction performance, and actuator constraints are included in the design process. Using this design method, phase lag was added using non-minimum phase zeros such that the beneficial plant dynamics could be used. This general control approach has application to lightly damped vibration and sound radiation problems where there are high bandwidth control objectives requiring a low controller DC gain and controller order.
Document ID
19980237285
Acquisition Source
Langley Research Center
Document Type
Other
Authors
Heatwole, Craig M. (Purdue Univ. West Lafayette, IN United States)
Bernhard, Robert J. (Purdue Univ. West Lafayette, IN United States)
Franchek, Matthew A. (Purdue Univ. West Lafayette, IN United States)
Date Acquired
September 6, 2013
Publication Date
February 1, 1997
Subject Category
Acoustics
Report/Patent Number
Rept-0278-1
HL-97-7
Funding Number(s)
CONTRACT_GRANT: NAG1-52142
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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