View Video Presentation: https://doi.org/10.2514/6.2023-0928.vid

Detonation wave dynamics were visualized in an optically accessible rotating detonation wave combustor operated with natural gas and gaseous oxygen. Chemiluminescence imaging was performed in the combustion chamber and the oxidizer manifold of the combustor as fuel injection location was continuously varied during the experiment. Optical access to the oxidizer manifold, fuel injectors, and the combustion chamber enabled characterization of location of maximum heat release in the chamber as a function of fuel injection location, towards (-z) and away (+z) from the oxidizer throat in a single experiment. As the fuel injector was translated further downstream, the main heat release area tended to exist closer to the fuel injection orifices. Bifurcation behavior was observed in the detonation standoff height: when the fuel injector was translated in the -z direction, the location of maximum heat release was located closer to the oxidizer throat when compared to a similar test conducted with +z translation.