高温真实气体底部流动的NS方程数值计算

本文数值模拟了高超音速飞行时钝锥的底部流动。采用轴对称NS方程并考虑真实气体效应。湍流模型采用修正的Baldwin-Lomax涡粘性代数模型，数值方法空间离散对流项采用显式NND格式，粘性项采用中心差。时间离散采用三阶的龙格-库塔法。真实气体模型采用考虑七种组分四种反应的汉森模型。给出了底部流场的压力和温度分布及各组分的浓度分布。可以看出在近底部区域高速流-绕过拐角就产生一回流旋涡区。由于温度变化很大，气体的热力学特性受气体离解、复合和振动能激发的影响。所以整个流动过程变得十分复杂。

Numerical Calculation of Base flow for NS equations of High Temperature Real Gas

This paper present a numerical simulation for the axisyminetric Navier-Stokes equations of hypersonic flow around a flat-based projectile considered real gas effect. The correctional Baldwin-Lomax turbulent model is employed. A NND (TVD type) explicit difference scheme with the flux vector splitting for convective terms and centered differencing for viscous terms is used to solve these equations. For the time integration, a three order Runge-Kutta method is used. The Hansen model considering seven species compositions and four chemical reactions was adopted as a model considered real gas effect. The pressure, temperature and chemical species distributions are obtained at base regions. It is seen that the high speed gas flow rounded corner at near base area and produced refluence and vortex area. Because temperature occurred very large change, The gas thennodynamic properties was affected by gas dissociation, recombination, ionization and vibrational excitation. Therefore, the flow is very complicated.