非结构网格热化学非平衡Navier-Stokes方程组求解技术研究  

Numerical Simulation of Nonequilibrium Thermalchemical Navier-Stokes Equations on Unstructured Mesh

作　　者：朱海涛 李岩 兰子奇 Zhu Haitao;Li Yan;Lan Ziqi(Chinese Aeronautical Establishment,Beijing 100012,China)

机构地区：[1]中国航空研究院数字仿真中心,北京100012

出　　处：《航空科学技术》2022年第11期27-33,共7页Aeronautical Science & Technology

摘　　要：采用非结构混合网格数值求解三维热化学非平衡Navier-Stokes方程组获得高超声速流场各组分气动热力学参数,并计算物面热流值。利用有限速率化学反应模型和二温度气体模型分别描述化学非平衡和热力学非平衡过程,通过Park振动——离解模型刻画化学非平衡和热力学非平衡耦合效应。无黏通量项采用AUSM格式离散;对无黏通量项和源项采用隐式时间推进格式,增强数值求解过程稳定性。数值算例表明,为得到正确的物面热流值,非结构混合网格边界层y+需减小至0.5,且网格增长率不超过1.4;采用元素摩尔数守恒关系式计算化学反应源项,可有效降低数值残差积累对计算小组分气体的不利影响,提高各气体组分计算准确度。Three-dimensional non-equilibrium thermal and chemical Navier-Stokes equations are numerically solved on hybrid unstructured mesh as well as aero-thermal dynamic parameters and heat transfer rate in the hypersonic flow.Finite rate chemistry model and two temperature gas model adopted to simulates chemical non-equilibrium and thermal non-equilibrium,while Park’s vibration-dissociation model to simulate couple of both non-equilibrium.AUSM scheme is used for inviscid flux,and source term and inviscid flux are implicit with Euler backward time scheme to overcome the numerical stiffness.Numerical results show that in order to predict wall heat flux,y+should be decreased to 0.5,and grid increasing ratio of boundary layer should be no more than 1.4.Besides,mole number conservation is critical to little mass friction components as to the accumulation of numerical residual errors.With conservation of mole number in finite rate chemistry calculation,numerical result of little gas components has been improved dramatically.

关 键 词：高超声速气动热 非结构混合网格 热化学非平衡 有限速率化学反应 二温度气体模型 小组分气体 

分 类 号：V221.3[航空宇航科学与技术—飞行器设计]