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David Jones and Raymond Sanzi

A Study on Hypersonic Combustion over Cavities and Wedges Using the Lafayette College Expansion Tube

Department: Mechanical Engineering
Advisor: Tobias Rossmann

The study of compressible flow is directly applicable to the aircraft industry in the design of supersonic and hypersonic aircraft engines. Scramjet engines are on the forefront of supersonic transportation development because of their simplicity and promising outlook for steady and reliable supersonic combustion. These engines have no moving parts and simply rely on shock waves produced at supersonic speeds to compress the intake air and provide means for ignition of the fuel. In order for these engines to be most efficient they must minimize entropy generation which can be accomplished by using oblique shock waves. Oblique shock waves decelerate very high speed flows to more moderate speeds inside the engine.  Additionally the Damkohler number, a number that compares the combustion rates with the flow speed, plays a very important role in hypersonic engine design. Understanding the Damkohler number allows for predicting shock detachment over wedges and cones in supersonic combustion.  Shock detachment can cause engine unstart, which is characterized by a drastic reduction in mass flow rate, causing potential damage to the engine and loss of aircraft. Also with these engines, the strong, stable combustion is both a requirement as well as a design challenge. Additional investigations will explore the flame-holding characteristics in supersonic cavity flows, examining the effects of acoustic wave propagation in cavities as well as mixture reactivity on combustion stability.

About David Jones:
Jones is a senior in his last semester at Lafayette College. He is studying mechanical engineering and is currently searching for jobs in the defense industry. Mac is researching hypersonic combustible flow under Professor Toby Rossmann with Lafayette’s new expansion tube impulse facility. In addition to research, Mac is an avid singer and is the music director of two of Lafayette’s a cappella groups, the Chorduroys and Soulfege.

About Raymond Sanzi:
Ray Sanzi III is a senior at Lafayette College pursuing a B.S. in Mechanical Engineering with a minor in Mathematics.  He was born and raised in Harrisburg, Pennsylvania.  He has been working under Professor Toby Rossmann since the Summer of 2014 designing and building an expansion tube to examine hypersonic combustible flow.  Ray has held leadership positions in the Lafayette College ASME student chapter.  Upon graduation, Ray plans to enter the defense industry.