Graduation Semester and Year

2008

Language

English

Document Type

Thesis

Degree Name

Master of Science in Aerospace Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Donald R Wilson

Abstract

When pressures and temperatures become so high in supersonic flight that it is no longer efficient to slow the oncoming flow to subsonic speeds for combustion, a scramjet (supersonic combustion ramjet) is used in place of a ramjet. Currently, the transition to supersonic combustion generally occurs at a freestream Mach number around 5.0 to 6.0. This research details analysis completed towards extending scramjet operability to lower Mach numbers, while maintaining performance at higher Mach numbers within the same flowpath as detailed in the Air Force solicitation AF073-058. The specific goal is to determine whether the scramjet starting Mach number can be lowered to Mach 3.50, and if not, what the constraints are that prohibit it and what the lowest possible starting Mach number for a scramjet is with today's technology. This analysis has produced many significant insights into current and required capabilities for both fuel and overall engine design in lowering the starting Mach number; these results are presented here. The analysis has shown that a scramjet with a starting Mach number of 3.50 is not currently possible with the fuels researched unless fuel additives or another addition to the system are used. However, a scramjet with a starting Mach number of 4.00 is possible with today's existing technology. This paper has designed the engine flowpath for this case; its specifications and resulting performance are also detailed here.

Disciplines

Aerospace Engineering | Engineering | Mechanical Engineering

Comments

Degree granted by The University of Texas at Arlington

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