Date of Award

9-1-2018

Document Type

Thesis

Degree Name

Master of Science in Aeronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

Marc D. Polanka, PhD.

Abstract

Internal combustion engines suffer from decreased performance as altitude is in- creased. This performance decrease can be overcome by increasing the pressure in the engine's intake manifold. Typically, this is accomplished with a turbocharger or supercharger. However, mechanical compression devices such as these suffer from decrease compression efficiency as the size of the device decreases. The size of the compression device scales with the amount of mass ow through the device, and the amount of mass ow is proportional to the size of the engine. This means a small turbocharger for a small engine is less efficient than a larger turbocharger coupled with a larger engine. An alternative means to compress fresh air sent to the engine is a wave rotor. The wave rotor avoids the efficiency loss of small mechanical compression de- vices by transferring energy from the exhaust gas to the fresh air by means of pressure waves. This research characterized the performance of a wave rotor sized for a 898cc industrial diesel engine. The wave rotor was initially tested while coupled to a burner instead of an engine in order to match and compare with previous testing. The results showed that the wave rotor had a maximum compression efficiency of 60% and that the efficiency depended on the exhaust temperature and rotor speed. The efficiency also depended heavily on the relationship between exhaust temperature and rotor speed since the rotor performance depends on the proper matching of these properties. Three different endwall configurations were also tested and compared. The results of the endwall comparison show that adding pockets to the endwalls increases the efficiency of the wave rotor at both on design and off design point conditions.

AFIT Designator

AFIT-ENY-MS-18-S-055

DTIC Accession Number

AD1063495

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