Honors Theses


Andrew Murray, Ph.D., David Myszka, Ph.D., and Paul Litke, AFRL/RQTC


Mechanical Engineering

Publication Date


Document Type

Honors Thesis


The objective of this thesis was to determine the feasibility of using an opposed-piston, opposed-stroke, diesel engine in utility aircraft. Utility aircraft are aircraft that have a maximal takeoff weight of 12,500lbs. These aircraft are often used for transportation of cargo and other goods. In order to handle that weight, many of the aircraft are powered by turboprop engines. Turboprop engines are a style of jet engine with power capabilities ranging from 500 to several thousand horsepower (hp). They are expensive engines, and in the case of the Piper Mirage, substituting the piston engine with a turboprop engine can increase the cost of the aircraft by $1million. In order to reduce the price tag, a piston-powered, propeller engine is desired. Currently, however, most modern piston driven aircraft engines max out around 400hp. The Piper Mirage referenced has a power output of 350hp. Because of this, it was necessary to see if an opposed-piston, opposed-stroke, diesel engine would be able to increase the power output in order to compete with the turboprop engine. The Foundation for Applied Aviation Technology determined that the minimum power output of an opposed-piston, opposed-stroke diesel engine should be 800hp at takeoff at an engine speed of 3600 revolutions per minute (rpm). Opposed-piston, opposed-stroke diesel engines have been used previously in aircraft and perhaps most famously in the Junkers Jumo 205 and 207 engines built in the 1940s. Both of these were opposed-piston, opposed-stroke, diesel engines that generated between 700 and 1000hp at takeoff. However, the Junkers engines were large engines used in large multi-engine aircraft. This thesis determines that the required size for an engine of this output can be reduced by 25% compared to the Junkers engine with a potential weight savings of up to 500lb, a better specific fuel consumption, and a greater power output of over 1200hp.

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This item is protected by copyright law (Title 17, U.S. Code) and may only be used for noncommercial, educational, and scholarly purposes


Undergraduate research


Aerospace Engineering | Engineering | Mechanical Engineering