Heat transfer characteristics of H2/air rotating detonation combustor

Abstract

The heat release process in a rotating detonation combustor (RDC) exhibits highly transient characteristics, posing significant demands on the thermal protection and management of the rotating detonation engine (RDE). In this work, the wall heat transfer characteristics of the RDC supplied by H2/air were experimentally examined with different equivalence ratios, mass flow rates, and initial wall temperatures. High-speed photography and dynamic pressure transducers were used to determine the propagation mode of the rotating detonation wave, while the wall temperature and heat flux were monitored by thermocouples. The results showed that the wall temperature and heat flux decreased along the axial direction. A parabolic temperature variation occurs when equivalence ratio increases from 0.8 to 1.3, and the extreme value appears at Φ = 1.2. The same trend happens between heat flux and equivalence ratio. The mass flow rate increase leads to the overall increase in the temperature and heat flux, with the spatial distributions remaining unchanged. The higher initial wall temperature leads to the increase in the combustor outer wall temperature, a reduction in the spatial variation of temperature distribution, a decrease in heat flux, and a reduction in the spatial variation of heat flux. Furthermore, an empirical model was developed to estimate the heat transfer characteristics. Valid calculations show that the temporal and spatial temperature function results in lower errors of peak temperature prediction by approximately 50% and higher spatial resolution compared to a constant heat flux boundary condition. The research findings provide a theoretical foundation for the RDE thermal protection issues.