Demonstration of active structural acoustic control of cylinders

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dc.contributor.authorSumali, Hartonoen
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T21:36:05Zen
dc.date.adate2010-05-11en
dc.date.available2014-03-14T21:36:05Zen
dc.date.issued1992en
dc.date.rdate2010-05-11en
dc.date.sdate2010-05-11en
dc.description.abstractActive control is applied to reduce noise emission from a vibrating elastic cylinder by exerting forces on the cylinder that cancel the noise-generating vibration. This technique is called Active Structural Acoustic Control (ASAC) (Fuller, 1987). Sensors are implemented using piezoelectric film, and actuators are implemented using piezoceramic material. Both analog and digital noise cancellation control algorithms are used to reduce the noise emission from the cylinder. Two-cylinder boundary conditions are taken as case studies. The first boundary condition is the open cylinder case. The second boundary condition is where the cylinder has an end plate bolted to each end. Actuator placement and the sensor design are done by first obtaining the natural frequencies and mode shapes of the cylinder using both analytical and experimental methods. Modal sensors developed and tested in previous work (Lee, 1989) are applied. After preliminary control experiments with analog feedback loop show that control can be done with the sensors and the actuators, digital signal processing hardware programmed with the filtered-x Least-Mean-Square adaptive control algorithm is used to control the vibration of the cylinder. The excitation is single-tone on-resonance. Acoustic - testing demonstrates that ASAC reduces the sound pressure level generated by the vibrating cylinder by up to 29 dB in the reverberant field. Vibration measurement reveals that the reduction in sound emission from the cylinder is a result of reduction in vibration. The adaptive controller reduces the vibration level by up to 68 dB.en
dc.description.degreeMaster of Scienceen
dc.format.extentxviii, 177 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-05112010-020232en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05112010-020232/en
dc.identifier.urihttp://hdl.handle.net/10919/42620en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1992.S952.pdfen
dc.relation.isformatofOCLC# 26033415en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1992.S952en
dc.subject.lcshCylinders -- Vibrationen
dc.subject.lcshNoise controlen
dc.titleDemonstration of active structural acoustic control of cylindersen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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