The number of jet and rocket noise studies has increased in recent years as researchers have sought to better understand aeroacoustic source and radiation characteristics using predominantly linear reconstruction techniques. While jet and rocket noise is often finite-amplitude in nature, little is known about the existence of shock formation and coalescence close to the source. A numerical expe...

BACKGROUND Due to high sound pressure levels (SPLs), noise produced by jet planes may be harmful to hearing of people working in their proximity. The aim of this study was to assess the effects of exposure to jet engine noise on technical staff hearing. MATERIAL AND METHODS The study comprised 60 men, aged 24-50 years, employed in army as technical staff and exposed to jet engine noise for 6-...

The present work involves measurements to examine the effects of initial conditions on aerodynamic and acoustic characteristics of a Jet at M=0.8 by changing the orientation of sharp edged orifice plate. A thick plate with chamfered orifice presented divergent and convergent openings when it was flipped over. The centerline velocity was found to decay more rapidly for divergent orifice and that...

The present work involves measurements to examine the effects of initial conditions on aerodynamic and acoustic characteristics of a Jet at M=0.8 by changing the orientation of sharp edged orifice plate. A thick plate with chamfered orifice presented divergent and convergent openings when it was flipped over. The centerline velocity was found to decay more rapidly for divergent orifice and that...

The purpose of this work is to examine the noise source distributions shock-containing supersonic jets at various pressure ratios corresponding fully expanded Mach numbers ranging from 1.0 1.4 in intervals 0.2 for nozzle exit diameters. Source location measurements using a phased array (beamforming), farfield jet measurements, and schlieren flow visualization are presented. It found that more c...

This study is motivated by the development of aircraft that use jet noise shielding by the airframe. Current methods to predict shielding from aircraft surfaces rely on formulae developed for diffraction of sound from omnidirectional point sources. However, the jet noise source is distributed and directional, thus requiring a different approach. In this study, the jet noise source is modeled as...