Impact of Tapered Combustion Channels on the Operation of a Rotating Detonation Engine

Date of Award


Degree Name

M.S. in Mechanical and Aerospace Engineering


Department of Mechanical and Aerospace Engineering


Matthew Fotia


Rotating detonation engines (RDEs) have continued to gain interest in the combustion research industry as a promising form of pressure gain combustion (PGC). The RDE has the potential for better performance than existing turbo-engines with its simplicity of design and manufacturing, lack of moving parts, increased power density, lower entropy, and high thermodynamic efficiency. The large pressure rise, or gain, in PGC can be used to produce increased thrust or extract shaft work. A lot of progress has been made in the last decade, however, there are still many challenges to overcome with RDEs. In particular, there are many complications with the feed mechanics of an RDE that influences the overall RDE performance. The goal of this study is to evaluate if changing the taper of the RDE channel impacts the feed mechanics and operation of the RDE. Current RDE research has mainly focused on two types of RDE designs - the radial and axial configuration. These configurations relate to the direction air and fuel are injected into the system. For this study, the reactants were fed axially. An existing axial RDE test rig in AFRL is utilized in this investigation, with new components made for the outer body, center body, and the inner and outer air injector plates of each configuration. In this research, three different configurations are tested. One design with no taper, which serves as the baseline. The other additional two configurations feature either a 15-degree taper inward or a 30-degree taper outward. Each of the three design configurations held certain constants in order to be able to make fair comparisons with the data. All designs have a channel length of 4.5 inches and the centerline of each profile starts at the same radial location. The designs have a nominal 0.9-inch channel width and all channel area ratios were held constant across all three designs. Each design configuration is tested across a wide range of equivalence ratios and mass flows. Pressure and temperature data is collected when each configuration is tested in the different operating conditions, and the data is analyzed and compared. Analysis of the different configurations will show how the geometric changes influence the performance of the RDE.


Aerospace Engineering, Engineering, Mechanical Engineering, Combustion, Detonation, Pressure Gain, Taper, Angle, Channel, RDE, Rotating Detonation Engine

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