连续旋转爆轰发动机参数特性的三维数值模拟

采用一步化学反应模型,基于任意坐标系下Euler控制方程,对连续旋转爆轰发动机(CRDE)进行了三维数值模拟研究, 详细分析了来流总压对CRDE参数特性的影响.研究发现:随着来流总压的增大,爆轰波峰值随之增大,但是燃烧室头部Laval型喷注段的壅塞比基本不变.不同来流总压下,可燃气体在燃烧室头部均以亚声速入射.随着来流总压的增大,燃烧室内流场的平均压强增大,但是其平均轴向流速基本不变.CRDE的流量、推力和比冲均随着来流总压的增加而变大;但是,不同来流总压下,CRDE的流量与Laval型喷注段最大流量之比不变,并且此比值约等Laval型喷注段的壅塞比.Laval型喷注段最大流量与来流总压成正比,因此以上分析从理论上进一步解释了CRDE的流量与来流总压成正比的原因. 

Three-dimensional numerical simulation of the parametric properties of continuously rotating detonation engine

Based on Euler equations with one-step chemical reaction model in generalized coordinates, three-dimensional numerical simulation of the continuously rotating detonation engine (CRDE) were performed to investigate the effect of inlet total pressure on its parametric properties. It is found that the peak value of the detonation wave increases with the inlet total pressure; however, the choking ratio of the injection Laval nozzle along the head end is not influenced by it. Across the whole head end of CRDE, combustible gas is injected into the combustion chamber subsonically for different inlet total pressures. With the increase of inlet total pressure, the average pressure inside the chamber increases obviously, but the average axial velocity changes little. The mass flux, force and specific impulse of CRDE increase with the inlet total pressure. However, the ratio of the mass flux of CRDE to the maximum mass flux of the injection Laval nozzle remains the same under different inlet total pressures, almost equal to the choking ratio of the injection Laval nozzle. As the maximum mass flux of the injection Laval nozzle has a linear growth with the inlet total pressure, the above analysis provides a theory explanation about why the mass flux of CRDE increases linearly with the inlet total pressure.