Relationship of detonation cell size and geometry to stability in 2-dimensional curved channels
Date of Award
M.S. in Mechanical and Aerospace Engineering
Department of Mechanical and Aerospace Engineering
In the pursuit of more relevant rotating detonation engines (RDEs) applications, one of the challenges is designing the correct geometry to maintain steady detonation. The geometry is espe-cially critical when transitioning from ground testing to viable flight propulsion where lower pres-sures and equivalence ratios will be used. This research investigates the stability of a detonation wave in a premixed system, as the cell size and geometry change. In order to isolate the desired effects of geometry on stability, a 2-D channel of rectangular cross section was designed as the test section.The tests were conducted at atmospheric pressure, with hydrogen and ethylene being the fuels and air being the oxidizer. The equivalence ratio was used as the primary independent variable to control cell size for all runs. When compared with results from similar experiments, similar trends are seen in both sets of data. From this and similar research, it can be concluded that in general the smallest cell size with the largest radius of curvature is best for the greatest stability. Differences between stability of rich and lean were also found. Other important information was gained in this research by using a more novel approach for test setup: a 2-D curved channel with straight legs on either end of the curve that is kept at atmospheric pressure. Using this novel test section setup, the data was collected by more traditional means with a high-speed camera capturing chemiluminescence from the combustion allowing detonation waves to be tacked easily with less setup. It also resulted in the ability to collect large amounts of data. The final new approach was to attempt to determine if different fuels follow the same stability trends for a given cell size and stability.
Fluid Dynamics, Aerospace Engineering, Detonation, Pressure Gain Combustion, Stability
Copyright © 2021, author.
Olson, Andrew James, "Relationship of detonation cell size and geometry to stability in 2-dimensional curved channels" (2021). Graduate Theses and Dissertations. 7060.