固体火箭发动机气-固两相近壁湍流特性大涡模拟研究  

Large eddy simulation investigation of near⁃wall turbulent behavior in gas⁃solid two⁃phase flows for SRM

作　　者：熊俊琦 胡恒瑜 田芮澎 陈良兵 黄海波 丁淼 王德鑫 XIONG Junqi;HU Hengyu;TIAN Ruipeng;CHEN Liangbing;HUANG Haibo;DING Miao;WANG Dexin(University of Science and Technology of China,Hefei230027,China;Xi'an Institute of Aerospace Solid Propulsion Technology,Xi'an710025,China)

机构地区：[1]中国科学技术大学近代力学系,合肥230027 [2]西安航天动力技术研究所,西安710025

出　　处：《固体火箭技术》2024年第4期519-528,共10页Journal of Solid Rocket Technology

摘　　要：固体火箭发动机内流场是典型的两相湍流流动,其流动特性对推进剂的燃烧影响极大。工程实践中大多采取雷诺平均(RANS)方法计算两相流问题,精度不高且无法解析流场中的湍流结构。采用大涡模拟(LES)与离散颗粒模型(DPM)分别对纯气相和气-固两相条件下的发动机内流场流动过程进行了数值模拟;通过对时均流场与瞬态流场的分析以及对近壁面(即注入表面)的物理参数开展时空平均,重点研究了近壁湍流特性;采用时空相关性分析与降阶变分模态分解(RVMD),重点探究了近壁面的旋涡脱落。结果表明,颗粒集中在内流场的中部,由于惯性的差异,越大的颗粒越接近中心;由于颗粒相与气相之间存在速度滞后和热量交换,颗粒相的注入会使内流场的轴向速度和温度降低、压强升高;发动机内流场会出现明显的壁面涡脱落,而颗粒相的引入会增加内流场的不规则扰动,从而使得旋涡脱落、破碎的位置提前,并减小涡结构的尺寸,使观察到的旋涡更加破碎;颗粒相的引入还能够减缓近壁面附近的温度梯度,抑制不稳定燃烧现象;同时,颗粒相的存在会使近壁面的径向速度降低、压力升高,降低和升高的幅度约为1.8%。对近壁面的压力振荡分析表明,颗粒相的存在能够抑制高频压力振荡的产生,使得纯气相条件下1853 Hz的振荡模态消失,只保留1425 Hz的模态。纯气相和气-固两相流场的脱涡位置分别为x/m=0.54、x/m=0.44,说明气-固两相流场旋涡脱落的位置更靠前。The internal flow field of a solid rocket motor is a typical two⁃phase turbulent flow,which profoundly impacts the combustion of propellant grain.In engineering practice,the Reynolds⁃Averaged Navier⁃Stokes(RANS)method is commonly used to⁃simluate two⁃phase flow problems,but its calculation accuracy is not high and the turbulent structures in the flow field cannot be re⁃solved.The internal flow field of a solid rocket motor under both pure gas and gas⁃solid two⁃phase conditions was numerically simu⁃lated by means of Large Eddy Simulation(LES)and the Discrete Phase Model(DPM).By analyzing the time⁃averaged and transi⁃ent flow fields and conducting spatio⁃temporal averaging of the physical parameters near the wall(i.e.,the injection surface),the turbulent characteristics near the wall were mainly studied.Spatio⁃temporal correlation analysis and Reduced⁃Order Variational Mode Decomposition(RVMD)were used to investigate vortex shedding near the wall.The results show that particles are concentrated in the central region of the internal flow field,with larger particles being closer to the center due to differences in inertia.The injection of particles reduces the axial velocity and temperature while increasing the pressure of the internal flow field due to the velocity lag and heat exchange between the particle and gas phases.Significant wall vortex shedding occurs in the internal flow field of the solid rocket motor,and the introduction of particles increases the irregular disturbances in the internal flow field,so that the positions of vortex shedding and breakup occur earlier and reduces the size of the vortex structures.The disturbances also result in more fragmen⁃ted observed vortices.Additionally,the introduction of particles mitigates the temperature gradient near the wall,suppressing unstable combustion phenomena.The presence of particles also reduces the radial velocity and increases the pressure near the wall,with the reduction and increase of approximately 1.8%.Analysis of pressu

关 键 词：固体火箭发动机 气-固两相流 大涡模拟 离散颗粒模型 

分 类 号：V435[航空宇航科学与技术—航空宇航推进理论与工程]