Author

Stephen Perry

Advisor

Koenig, Keith

Committee Member

Murray, Nathan E.

Committee Member

Sescu, Adrian

Date of Degree

1-1-2018

Document Type

Graduate Thesis - Open Access

Major

Aerospace Engineering

Degree Name

Master of Science

College

James Worth Bagley College of Engineering

Department

Department of Aerospace Engineering

Abstract

Noise pollution from aircraft is an ever-increasing issue in urban areas. Venting exhaust over body panels could reduce perceived sound pressure levels (SPL) by absorption or redirection. This paper investigates the farield spectra and sound propagation of a flat panel held near an axis-symmetric supersonic jet. In contrast to typical radial acquisition, Overall sound pressure level (OASPL) contours are constructed from a 9 by 23 cartesian acquisition gird, spaced equidistantly at 3.67 Jet Diameters (Dj). Three panel configurations each at three nozzle pressure ratios (NPR) are discussed. Additionally, a source finding algorithm is developed and shows source locations by frequency. Panel presence for nozzle design conditions result in a near flat increase in SPL across the acquired spectrum, while over and under expanded nozzle cases show the propagation of resonant modes.

URI

https://hdl.handle.net/11668/19416

Comments

Sound Pressure Level||Jet Noise||signal propagation||farield||spectra||SPL||OASPL||noise source location||microphone correction||Overall sound pressure levels

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