Experimental investigation of microfabricated bipropellant rocket engines

As satellite missions begin to require smaller satellites, launch systems and attitude control thrusters of reduced mass will be required. Microrocket engines could provide a low mass, high specific impulse, modular answer to these needs. These small rocket engines would produce thrust of order of 10's of Newtons at a thrust-to-weight of over 1000, over 10 times the thrust-to-weight of conventional chemical liquid bipropellant engines. The first microrocket engine thrust chamber and nozzle design measures 18 x 14 x 3 mm and is fabricated from single crystal silicon using MEMS microfabrication techniques offering the promise of low cost in production. This thesis describes an experimental investigation of bi-propellant microrocket engines and encompasses the fields of materials, microfabrication, combustion and chemical kinetics, instrumentation, packaging, and fluid dynamics. It builds on London's earlier gaseous propellant work, expanding the operating envelope of his motors to higher thrust levels and using these results to design liquid bi-propellant regeneratively cooled engines. Failure analysis of the original devices indicated failures were primarily caused by structural design flaws. Second generation gaseous propellant devices were built and tested. Providing reliable packaging interfaces between the macro test setup and the device proved very difficult. Two packaging methods involving modified geometries and glass seals were developed and allowed higher performance tests. Combustion experiments spanned a range of oxidizer-to-fuel ratios by mass of 1.6 to 2.5 and reached a maximum chamber pressure of 30 bar with a maximum thrust of 3 N at a thrust coefficient of 1.12. A maximum c* of 1650 m/s has been recorded.

Department dc:contributor.department

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

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Protz, Christopher S. (Christopher Stephen), 1977-

Advisor dc:contributor.advisor

• Alan H. Epstein.

• 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/1721.1/17794

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/17794