底部排气弹三维湍流燃烧的数值模拟

Numerical simulation of three-dimensional turbulent combustion of the base bleed projectile

为了研究底部排气减阻机理,发展了一套多块结构网格三维湍流流动与燃烧的计算软件(MSTCS-3D)。计算软件采用3阶MUSCL重构方法并耦合Steger-warming通量分裂技术,求解雷诺时均Navier-Stokes方程,湍流流动模型采用k-ωSST模型,化学反应动力学模型采用CO-H2-O2反应系统8组分12步基元反应模型,湍流燃烧模型采用二阶矩模型。采用该计算软件,分析了底部排热空气/真实气体、来流马赫数对底部排气弹底部流场结构的影响以及对减阻特性的影响。计算结果表明,底排真实气体和底排热空气数值模拟结果差别较大;底部二次燃烧主要发生在弹底的二次回流区;来流马赫数越大,初始回流区后退距离更大,同时减阻效果也越好;编制的计算软件具有较高可靠性,可作为深入分析底部排气减阻机理的工具。

A multi-block structured grid 3D turbulent flow and combustion calculation software（MSTCS-3D） were developed in order to study the drag reduction mechanism.The Navier-Stokes equations were solved by the MUSCL reconstruction method coupled with steger-warming flux splitting technique in the calculation software by using the k-to SST turbulent flow model, CO-H2-O2 reac- tion system chemical kinetic model and a second-order moment turbulent combustion model.The structure of the bottom flow field and the drag reduction characteristics were analyzed by means of the MSTCS-2D/3D.The results show that the numerical simulation results of the hot air and real gas are different; with the increase of Mach number, the initial recirculation zone will retreat a greater distance and the drag reduction effect will be better;the secondary combustion mainly occur in the second recirculation zone;calcu- lation software has high reliability,which can be used as a tool for analysis of drag reduction mechanism.