Development of a liquid-fueled micro-combustor

Advances in Micro-Electro-Mechanical Systems (MEMS) have made possible the development of shirtbutton-sized gas turbine engines for use as portable power sources. As part of an effort to develop a microscale gas turbine engine, this thesis presents the modeling, design, fabrication, and experimental characterization of a microcombustor that catalytically burns JP8 fuel. Due to high energy densities stored in hydrocarbon fuels, microscale heat engines based on them are estimated to have specific energies about one order of magnitude higher than those of current battery systems. In addition, utilizing a commonly available logistics fuel would provide advantages for military applications. Thus, a microengine burning JP8 fuel is attractive as a portable power source and potential replacement for batteries. The thesis first presents a number of models developed to design the fuel vaporizer, the fuel-air mixing chamber, and the combustion chamber. Among these is a reduced-order mass transfer model that simulates catalytic combustion of a slow diffusing hydrocarbon fuel. A two-phase heat transfer model was also developed to design an on-board fuel vaporizer with an array of micro-channels. Using the model results, a liquid-fueled micro-combustor test rig with a combustion chamber volume of 1.hcc and an overall die size of 36.4 mm x 36.4 mm x 6.5 mm was built. This device is a hybrid structure composed of silicon, sapphire, and glass. Deep reactive ion etching was mainly used to fabricate the silicon parts. The sapphire and glass parts were built by ultrasonic machining. The liquid-fueled micro-combustor was then experimentally characterized. Two configurations were tested and compared; one with the whole combustion chamber filled with a catalyst, and the other with a catalyst filling the chamber only partially.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Peck, Jhongwoo, 1976-

Advisor dc:contributor.advisor

• Ian A. Waitz.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/45271

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/45271