关键词: 旋转爆震, 爆震波频率, 涡轮, 流场时空特征, 气动激励

Abstract: Turbine-based rotating detonation engines promise transformative performance enhancements for aerospace propulsion systems. However, the high-frequency unsteady environment induced by rotating detonation waves within the combustor poses a critical challenge for the efficient integration of the combustor and turbine. The characteristic parameters of detonation waves critically influence the internal turbine flow and unsteady blade aerodynamic excitation, yet the effects of frequency variation remain poorly understood. To address this issue, the present study establishes inlet detonation conditions with frequencies ranging from 5kHz to 20kHz based on a moving shock wave model, systematically investigating the influence of detonation wave frequency on the spatio-temporal evolution of the turbine flow field and blade aerodynamic excitation characteristics. The results demonstrate that, in addition to the typical rake-type shock envelope, subsequent reflected waves from the vane surfaces can form a more generalized upstream-propagating wave system. A higher shock sweeping frequency makes it more difficult for the upstream shock wave to induce a strong downstream wave system, but it enhances the temporal stability and spatial uniformity of the flow field. With regard to blade aerodynamic excitation, the time-averaged peak pressure and fluctuation amplitude on the blade surface far exceed those under uniform inflow at all detonation frequencies, but both decrease with increasing frequency: compared with the 5kHz case, the average pressure peak and fluctuation amplitude at 20kHz are reduced by 22.4% and 46.1%, respectively. Meanwhile, the time-averaged cascade load increases with frequency, whereas its unsteady fluctuation decreases, with a reduction of 26.4% at 20kHz relative to the 5kHz case. These findings indicate that, within the frequency range investigated, increasing the detonation frequency can facilitate combustor–turbine matching and achieve a design balance between high aerodynamic loading and low vibration risk.

Key words: rotating detonation, detonation wave frequency, turbine, spatio-temporal characteristics of flow field, aerodynamic excitation