受限空间中斜爆震波波系结构及其演化

Wave structure and structural evolution of oblique detonation waves in confined space

关键词:  斜爆震波  波系结构  受限空间  演化过程  膨胀波

Key words:  Oblique detonation wave  Wave structure  Confined space  Evolution process  Expansion wave

摘要:

为了研究真实发动机中受限空间内斜爆震波的宏观波系结构，采用欧拉方程结合详细反应机理的数值模拟方法，开展了受限空间的斜爆震波的数值模拟，分析了不同转折角下斜爆震波波系结构及其演化过程。结果表明，在上壁面转折处膨胀波的影响下，斜爆震波反射形成的马赫杆在前移过程中衰减，最终会在上扩张壁面附近形成高温回流区和低温三角区的稳定结构，三角区由转折处波系、回流区和下游斜爆震波组成。随转折角增大，最终在转折处点处依次形成激波、弱压缩波和膨胀波，与斜爆震波相交，交点下游的斜爆震波衰减，在末端出现解耦现象。

Abstract:

In order to study wave structure of oblique detonation wave in the confined space of a real engine， numerical simulations were carried out to investigate oblique detonation wave in confined space based on Euler equations along with a detailed chemical mechanism. The wave structure and structural evolution were analyzed with different angel of the outward turning wall. Results show that Mach stem benefits from the oblique detonation wave reflection of the wall and then propagates upstream， in which Mach stem is reduced by the expansion wave emanated from the turning point at the upper wall. Stable structure featured with high temperature recirculation zone and low temperature triangle zone are formed at the outward turning wall finally. The triangle zone comprises of the wave introduced from the turning point， recirculation zone and oblique detonation wave downstream. As the angle of the outward turning wall increases， shock wave， weak compression waves and expansion waves are formed at the turning point successively， which interact with the oblique detonation wave. The oblique detonation wave downstream of the interaction point is reduced and decoupled combustion occurs at its end.