Modeling of Herschel/Quincke-Liner Systems for the Control of Aft Fan Radiation in Turbofan Engines

Simple item page
dc.contributor.authorde la Riva, Diego Horacioen
dc.contributor.committeechairBurdisso, Ricardo A.en
dc.contributor.committeememberDevenport, William J.en
dc.contributor.committeememberJohnson, Martin E.en
dc.contributor.committeememberWicks, Alfred L.en
dc.contributor.committeememberKwan, Hwaen
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2014-03-14T20:13:24Zen
dc.date.adate2006-07-07en
dc.date.available2014-03-14T20:13:24Zen
dc.date.issued2006-06-01en
dc.date.rdate2009-07-07en
dc.date.sdate2006-06-19en
dc.description.abstractCommercial aviation transportation has experienced an overwhelming growth over the years. However, this expansion has encountered an important barrier: noise. Several studies have shown that residents in these areas experience problems such as stress and sleep disturbance. These problems have translated into demands for a better quality of life from airport residents which in turn have translated into more stringent aircraft noise regulations. As a result, large amounts of resources have been diverted towards the improvement of existing noise attenuation technologies and the development of more effective ones. In terms of turbofan generated noise, the most widely used technology is that of absorbent materials or liners. In recent investigations Alonso et al. have combined Herschel/Quincke (HQ) tubes with liners. This combination has the potential of effectively controlling pure tones and broadband noise in inlet sections of modern turbofan engines. Since a comprehensive approach for engine noise reduction will involve both inlet and aft HQ-Liner systems, additional research efforts were needed to evaluate their performance at reducing aft fan radiation In the present work, a combination of traditional liners and Herschel/Quincke waveguide resonators for aft fan radiation control is proposed. A theoretical model is developed in order to predict noise reduction due to such systems. The newly developed tool was then utilized to design an HQ-liner that was installed and tested in the aft section of the NASA Active Noise Control Fan (ANCF) rig. This experimental data was utilized to prove the potential of these systems and to validate the mathematical model. Analytical predictions correlate well with experiments. The NASA ANCF rig is not representative of a real turbofan engine. In order to assess the behavior of HQ-Liners in a more realistic environment a new system was specifically designed for a generic turbofan engine and its performance analyzed. The sound field inside HQ tubes has been described assuming plane waves only. This assumption limits the model to frequencies below the tube first resonance. In order to overcome this limitation a new model accounting for higher order modes inside the tubes has been developed.en
dc.description.degreePh. D.en
dc.identifier.otheretd-06192006-224344en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06192006-224344/en
dc.identifier.urihttp://hdl.handle.net/10919/28080en
dc.publisherVirginia Techen
dc.relation.haspartdissertation.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectBypass noiseen
dc.subjectTurbofan noiseen
dc.subjectHerschel-Quincke tubeen
dc.subjectAcoustic lineren
dc.subjectAeroacousticsen
dc.titleModeling of Herschel/Quincke-Liner Systems for the Control of Aft Fan Radiation in Turbofan Enginesen
dc.typeDissertationen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
dissertation.pdf
Size:
4.47 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations