Experimental Characterization of High-Frequency Heat Flux in a Rotating Detonation Engine

Abstract

Experimental results are shown for the high-frequency surface heat flux into the containing walls of a 6-inch water-cooled Rotating Detonation Engine (RDE). Typical RDE operating regimes require active cooling techniques to dissipate the high instantaneous heat released by the rotating detonation waves and following deflagration waves. By mounting high-frequency thin film heat flux gages on the surface of water-cooled walls, the heat flux to the wall during RDE operation is determined. This paper presents the first high-frequency surface heat flux waveforms on the wetted surface of an RDE published to date. During relatively steady operation at 0.11 kg/s flow rate and an equivalence ratio of 1.0, several types of waveforms were characterized near the air injection plane. The gage at this position recorded heat flux spikes over 9 MW/m and below 1 MW/m. Averaged data suggests that the bulk heat flux at this position is of the same order of magnitude, but slightly lower than the bulk heat flux seen in similar tests run to thermal equilibrium. Such data is critical to understanding both RDE operation as well as the thermal conditions RDEs must be designed to withstand.