RECIPROCATING ENGINE AND EXHAUST VIBRATION AND TEMPERATURE LEVELS IN GENERAL AVIATION AIRCRAFT
NATIONAL AVIATION FACILITIES EXPERIMENTAL CENTER ATLANTIC CITY NJ
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The engine and exhaust system vibration and exhaust gas and metal temperature levels were determined for flight and ground conditions on several single-engine aircraft for purposes of establishing exhaust system and heat exchanger design and test criteria. The temperature data were presented as a function of engine compression ratio and the vibration data were plotted against engine horsepower to foster the general utilization of the information. Method of data presentation permits the estimation of exhaust gas temperatures for horizontally-opposed, reciprocating engines. Temperature measurements indicated uneven heating of the muffler outer wall heat exchanger surface reflecting uneven flow of the exhaust gases through and around the baffles and diffusers. Baffles and diffusers within the mufflers of engines with compression ratios of 8.51 or higher are exposed to exhaust gas temperature levels under which standard construction materials AISI 321 and AISI 347 stainless steels become marginal with respect to high-temperature oxidation, carburization, and attack by lead compounds. Vibration of general aviation aircraft engines was noted to increase with increased power rating and reached maximum intensities under takeoff conditions.
- Reciprocating and Rotating Engines