Spatio-Temporally Resolved Experimental Characterization of Rotating Detonation Rocket Engine Heat Transfer

Reliable prediction of Rotating Detonation Rocket Engine (RDRE) heat transfer presents a critical on-going
challenge for developing flight ready hardware. Traditional spatial and temporally averaged techniques for
measuring RDRE heat flux hinder the development of convective heat transfer correlations that capture the
multidimensional, complex detonation wave and oblique shock structures. In the following paper, detailed
analysis on a series of experimental techniques to capture temporally and spatially resolved heat transfer
measurements within RDREs is presented. First the Atomic Layer Thermopile (ALTP) is applied as a method
to temporally and spatially resolve the heat flux in the RDRE. An additional technique is then presented with
the Coaxial Surface Junction Thermocouple (CSJT) to enhance spatial resolution for heat transfer
measurements with greater temporal accuracy than traditional low speed thermocouples. Finally, heat
conduction within the instruments is modeled with numerical Finite Difference Method (FDM) to evaluate
measurement performance and identify suitable practices. Prior instantaneous heat flux and wall temperature
measurements and calculations from the gaseous hydrogen-air Turbine-integrated High-pressure Optical RDE
(THOR) at Purdue University are used as references for the evaluation of sensors.