连续旋转爆轰燃烧室增压特性的数值研究

Numerical Investigation on Pressure Amplifying Characteristic of Continuously Rotating Detonation Combustor

为了分析爆轰燃烧室几何尺寸对增压特性的影响,利用二维欧拉方程数值研究了当量H2/Air在连续旋转爆轰燃烧室中的燃烧流场情况。研究表明:在准稳定状态下爆轰燃烧流场特征参数随时间呈周期性振荡,且其振幅保持不变;横波及局部爆炸波的存在是爆轰波后侧附近总压沿x轴呈现波动变化的主要原因;影响连续旋转爆轰燃烧室增压特性的直接因素为斜激波的高度及爆轰波强度,减少轴向尺寸或增加周向尺寸可增强其增压特性。连续旋转爆轰燃烧室的增压比高达2.52,与传统的燃烧室相比,大大提高了燃气的做功能力。

Based on two-dimensional compressible Euler equations,the rotating detonation flow field with stoichiometric hydrogen-air mixture is investigated numerically and the effects of geometry size of continuously rotating detonation combustor(CRDC)on pressure amplifying characteristic are analyzed. The results show that the flow field parameters present periodic oscillation with constant amplitudes at the quasi-steady-state. Total pressure fluctuates twice along x axis at the rear of detonation wave because of transverse waves and local explosion waves. Length of oblique shock wave and detonation strength play the important roles in pressure amplifying characteristic. It can be enhanced by decreasing axial size or increasing azimuthal size. Calculated pressure-amplifying ratio at CRDC is as high as 2.52,which implies a higher potential power of gas at the exit of CRDC than that in traditional combustors.