Time-Resolved Stagnation Pressure Measurement Technique in a Rotating Detonation Rocket Combustor

Megahertz rate schlieren images are captured to visualize the time-varying spatial structure of underexpanded flow exhausting from a Rotating Detonation Combustor (RDC). Periodic oscillations of the jet boundary divergence angle are observed in response to stagnation pressure changes induced by the passage of rotating detonation waves contained within the combustor. The time-averaged divergence angle of the exhaust plume is measured, and the average stagnation pressure of the combustor is reported. The average stagnation pressure obtained through the analysis of schlieren images is shown to converge to a value within ±��% of the Equivalent Available Pressure – an average stagnation pressure obtained from the thrust produced by the RDC. Results indicate that non-intrusive optical analysis of the RDC plume structure provides a means to quantify the stagnation pressure of the combustor.