Experimental Studies on Detonation Initiation and Stabilization in Supersonic and Hypersonic Flows

Detonation-based propulsion systems are desired due to their potential for thermodynamic cycle efficiencies much higher than traditional, constant pressure deflagration-based systems. Additionally, the ability to propagate in high-Mach number flow regimes makes detonations promising for supersonic combustion applications. Oblique detonation waves (ODW) are a subset of detonations that have been proposed for use in a number of detonation-based propulsion concepts. However, most studies into initiation and stabilization of ODWs have been numerical studies without sufficient experimental validation. Experimental setups, such as expansion tubes, typically have extremely limited run times (\u3c 100 ms) due to practical difficulties in attaining the necessary conditions in a continuous flow ( \u3e 1 second) system. Those difficulties include the need for high pressures, temperatures, and the correct chemical composition in order to create a supersonic flow that is favorable for detonations. The work described within this dissertation focuses on the facility design and investigations into supersonic combustion and detonation stabilization using continuous flow facilities, including the HyperReact Facility. Using HyperReact, tests were conducted with varied pressures, temperatures, geometries, and flow compositions. From those tests, the operability map of the system was created, from which 3 major reaction regimes were defined. Those regimes include: intermittent, low-intensity reactions (regime I), intermittent, higher-intensity reactions (regime II), and quasi-stable reactions (regime III). Multiple diagnostics were performed, including high-speed shadowgraph and chemiluminescence imaging, Raman spectroscopy, as well as pressure and temperature measurements at multiple locations