Experimental Study of Oblique Detonation Waves with Varied Ramp Geometries

Advancements in the study of oblique detonation wave (ODW) initiation and stabilization have primarily been within the purview of numerical simulations and limited laboratory experiments. However, the recent publication of an experimentally controlled stabilized ODW via a 30-degree ramp by the HyperReact facility at the Propulsion and Energy Research Laboratory represents a breakthrough towards developing standing detonation engines as a reliable propulsion system of the future. Additional work was conducted with ramps at 12-degrees and 20-degrees, although ODW was not achieved. Comparison of those results with the successful test cases using the 30-degree ramp can provide insight into the system. In that vein, this paper presents a parametric study of varying ramp angle configurations at low (I) to moderate (II) regime conditions, where total pressure and total temperature denote the regime where the test cases reside. For the basis of comparison, diagnostics using simultaneous high-speed shadowgraph and broadband chemiluminescence are used to visualize shock structures and combustion products within the hypersonic flow.