Dissertation/Thesis Abstract

An Experimental Study of Thrust Augmentation with Asymmetrical Nozzle Driven Pulsed Ejector
by Rodriguez, Orlando, M.S.E., The University of Texas Rio Grande Valley, 2019, 111; 22584822
Abstract (Summary)

With the emergence of V/STOL vehicles and unmanned aircrafts has come the resurgence of thrust augmentation through an ejector. The use of an ejector has many benefits such as being lightweight and simple design to manufacture. In this study a hot steady jet and a cold steady/unsteady jet was tested. The hot steady jet was produced by a JetCAT PX-180 rxi with a two-inch diameter nozzle exit. The hot steady jet was compared to the cold free steady and unsteady cases. The cold jet was tested under free steady and unsteady condition, as well as steady and unsteady ejector conditions. The unsteady cold jet was produced by pulsing compressed air with a flow chopper. A direct measurement system was used to measure thrust values with and without the ejector. Four asymmetric nozzles of circular, diamond, elliptic, and rectangular were used during experimentation. Findings included that the circular, diamond, ellipse, and rectangular nozzle all performed better when under a pulsed ejector case in comparison to a steady ejector case due to the vortex ring entraining addition secondary air. It was also found that as Mach number increases thrust decreases because with higher speeds the vortex ring is no longer as organized and therefore no longer entrains as much air.

Indexing (document details)
Advisor: Choutapalli, Isaac
Commitee: Freeman, Robert, Vasquez, Horacio, Jones, Robert, Crown, Stephen, Acosta, Greg
School: The University of Texas Rio Grande Valley
Department: Department of Mechanical Engineering
School Location: United States -- Texas
Source: MAI 81/6(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Mechanical engineering, Aerospace engineering
Keywords: Asymmetric nozzle, Cold jet, Ejector, Jet turbine, Pulse jet
Publication Number: 22584822
ISBN: 9781392665022
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