镁颗粒-空气混合物一维非稳态爆震波特性数值模拟研究  

Numerical investigation of one-dimensional unsteady detonation wave characteristics of magnesium particle-air mixture

作　　者：刘龙 夏智勋[1] 黄利亚[2] 马立坤[1] 陈斌斌[1] Liu Long;Xia Zhi-Xun;Huang Li-Ya;Ma Li-Kun;Chen Bin-Bin(Science and Technology on Scramjet Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China;College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学空天科学学院高超声速冲压发动机技术重点实验室,长沙410073 [2]国防科技大学空天科学学院,长沙410073

出　　处：《物理学报》2020年第19期120-132,共13页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51706241,11572349)资助的课题.

摘　　要：镁颗粒因其能量密度高、点火特性和燃烧效率好的优势,作为燃料或添加剂应用于爆震燃烧动力系统具有广阔的应用前景.本文建立了镁颗粒-空气混合物的一维非稳态爆震波模型,数值模拟爆震波传播过程及其内部流场分布.研究结果表明,爆震波传播过程中爆震波压力峰值和空间分布均存在小幅度波动.考虑燃烧产物氧化镁在颗粒表面的沉积过程,镁颗粒的反应速率和爆震波的稳定传播速度增大.在考虑爆震管壁面损失的前提下,随管径减小,爆震波稳定速度和厚度均减小,同时爆震波内未能反应的镁颗粒比例增大.考虑壁面损失条件下,爆震波稳定传播速度以及厚度均随颗粒初始粒径的增大而减小,且镁颗粒初始为双粒径分布时对应的爆震波速度和厚度明显低于镁颗粒初始为统一单粒径的工况;稳定传播速度随颗粒初始当量比的增大而先增后减,厚度随初始当量比的增加单调递减.MgO熔化发生在CJ平面附近时,MgO熔化过程对爆震波传播稳定性无明显影响,而爆震波厚度显著增大.选取适当的点火区参数,能够使爆震波达到稳定传播状态所经历的距离明显缩短.In this paper,a one-dimensional unsteady model is established for the detonation of magnesium particle-air mixture.Through numerical simulation,the influences of the loss caused by the side wall of the detonation tube,the diameter of the magnesium particles,the initial equivalent ratio of the magnesium particles,and the deposition process on the surface of the particles,and the ignition energy on the structure and development of the detonation wave and the distribution of the flow field parameters inside the detonation wave are obtained.The studies show that there appear oscillations during the propagation of the fully developed one-dimensional unsteady detonation wave of magnesium particle-air mixture,but the amplitude is less than 1 m/s.Considering the loss of the wall,the pressure and temperature inside the detonation wave decrease with the inner diameter of the detonation tube decreasing,thus leading the propagation velocity and the thickness of the detonation wave decreasing.In the case without the wall loss,as the initial particle size increases,the detonation wave velocity remains unchanged,and the detonation wave thickness monotonically increases.With the wall loss taken into consideration,the stable velocity and thickness of detonation wave are lower than without considering the wall loss under the same initial conditions.Both the difference between the velocities and the difference between thickness values under the conditions with and without considering the wall loss increase as initial particle size increases.The detonation wave thickness with a double-size-distribution initial particle size is more than that with an equivalent single-size-distribution.Meanwhile the stable propagation velocity of the former is less than that of the latter.In the range of initial particle equivalent ratio of 0.5–2,as the initial equivalent ratio increases,the stable velocity of ideal detonation wave first increases and then decreases,and the thickness of the detonation wave first decreases and then increases.Conside

关 键 词：异相爆震 镁颗粒燃料 表面沉积 壁面能量损失 

分 类 号：O382[理学—流体力学]