初始点火条件引起的三维旋转爆震波单/双波传播模式

在不同工况下，旋转爆震波能够以单波、双波、多波模式进行传播.但在同一工况下，是否存在不同模式的稳定传播爆震波还有待进一步研究.基于Euler方程，耦合氢气/空气的有限化学反应速率模型，并采用高分辨率的5阶有限差分格式WENO-PPM5离散对流项，对三维旋转爆震波进行了数值模拟.计算结果表明，在同一特定工况下，旋转爆震波能够以两种不同的传播模式稳定传播，即单波模式和双波模式.详细地对比了两种传播模式下的流场特征、爆震波传播特性、推力性能等.在同一工况下，两种传播模式的爆震波周向传播速度相差不多，但双波模式的频率约为单波模式的2倍；双波模式下质量流量、比冲、推力的平均值均略高于单波模式；且双波模式的可燃混气层高度约为单波模式的1/2，这有助于缩小旋转爆震发动机的长度，使之更加紧凑. 

Single-Wave Mode and Double-Wave Mode Caused by Initiation Condition in Three-Dimensional Rotating Detonation Wave

Based on Euler equations associated with finite-rate chemical reaction mechanism of hydrogen/air mixtures, numerical calculations were performed by using a fifth-order WENO-PPM5 scheme for spatial discretization to simulate the rotating detonation in an annular chamber. Results show that under specific condition, the rotating detonation wave can propagate in two different modes, i.e. single-wave mode and double-wave mode. Comparison was made between the two modes, including the characteristic of flowfield, the feature of detonation propagation, the propulsion performance. Under the same condition, the circumferential velocity of detonation propagation in two modes is approximately equal, and the frequency of double-wave mode is twice as that of single-wave mode; the time-averaged mass flux, specific impulse and thrust of double-wave mode are all a little higher than that of single-wave mode. The height of fresh mixture in two-wave mode is about a half of that in single-wave mode, which is favorable to shorten the length of rotating detonation engine.