Coupling study of supersonic turbine stage and two-dimensional hydrogen/air rotating detonation combustor

Abstract

The hydrogen/air rotating detonation turbine engine has the advantages of self-supercharging, small entropy increase, high thermal efficiency, high thrust-to-weight ratio, low fuel consumption, and low carbon emissions. However, the high-frequency and high-speed oscillation characteristics of the outflow of the rotating detonation combustor pose challenges for the turbine to extract work efficiently. In this study, a supersonic turbine stage designed using the Python code of the method of characteristics coupled with a two-dimensional rotating detonation combustor is numerically investigated. The propagation characteristics of the detonation wave in the aligned mode and misaligned mode and interaction with the supersonic turbine stage are carefully discussed. The results show that the coupling of the supersonic turbine stage and the rotating detonation combustor will cause the detonation wave to change from a single-wave mode to a three-wave co-propagating mode. The Kelvin–Helmholtz instability of the slip line increases after passing through the induced oblique shock. In the multi-wave mode, the detonation wave is self-adaptive, and multiple detonation waves interact to automatically adjust the propagation velocity, intensity, and distance of each detonation wave, and finally achieve a dynamic balance. The supersonic turbine stage has good operating performance under the condition of rotating detonation flow, its power level can reach 110 kW, and the maximum stagnation adiabatic efficiency of the supersonic turbine stage can reach 86%. The supersonic turbine guide vanes can greatly reduce the oscillation amplitude of the incoming flow. In the aligned mode, the supersonic turbine guide vanes has a more obvious effect of suppressing the amplitude of the incoming flow. The total pressure loss of the supersonic turbine stage is smaller, and the supersonic turbine rotor can extract work more efficiently in the aligned mode. These findings provide a valuable reference for further research on the hydrogen/air rotating detonation turbine engine, ultimately leading to the practical application of an energy-saving, high-efficiency, and low-emission hydrogen/air rotating detonation turbine engine.