Design and analysis of an additively manufactured rotating detonation rocket engine chamber for calorimetry and thermal management assessment

Abstract

Additively manufactured, water-cooled test hardware was developed for calorimetry analysis in a rotating detonation rocket engine architecture. The water-cooled chamber hardware was designed for extended-length hot-fire testing at the Air Force Research Laboratory (Rocket Propulsion Division) in Edwards, CA, and features sensors to recover local heat fluxes at locations of interest from the injector face and global heat transfer to the combustor walls. A design leveraging metal additive manufacturing was utilized to generate cooling channels to “snake” around sensor ports, enabling heavy instrumentation of a monolithic, axially cooled chamber without compromising coolant flow for traditional subtractive manufacturability. Conjugate heat transfer analyses (CHT) were performed to predict the temperatures within the chamber wall of the test hardware at steady state conditions for a given coolant flow rate and to determine the impact of channel snaking on local heat transfer and thermocouple placement. The calorimetry hardware developed is a critical step in demystifying the otherwise convoluted heat transfer mechanisms within rotating detonation rocket engine architectures, and will enable long-duration hot-fire tests hitherto unachievable with traditionally-manufactured rotating detonation rocket engine hardware designs. With the design complete, manufacture of the chamber is anticipated to be completed by the end of Winter 2023, and hot-fire testing and performance characterization of the chamber are planned to be performed at AFRL-Edwards in Spring 2023. Subsequent measurements of temperature and heat flux during hot-fire operation are expected to provide unique insights into the practical application of detonation-based thermodynamic cycles for rocket propulsion research and development.