高超声速火箭橇导流板气动参数数值研究

Numerical investigation on aerodynamic parameters of deflector of hypersonic rocket sled

为减小高超声速火箭橇在轨运动时由于气动升力导致的运行不稳定,故在其前、后滑靴上安装导流板以提供负升力。以考虑粘性的稳态三维可压N-S方程为控制方程,采用经熵修正的Roe空间差分格式、LU-SGS隐式时间推进格式,使用两方程可实现k-ε湍流模型,对14种气动外形进行了CFD仿真,从导流板气动效果、流场特性、外形优化和速度影响四个方面进行了研究。结果表明:导流板可增大火箭橇负升力,增强其运行稳定性;火箭橇流场存在大量激波反射、激波干扰行为,影响着导流板周围流场的密度、温度、速度、湍动能与涡线分布,也影响着导流板所受的气动力;导流板的尺寸及安装角会影响导流板的气动性能,且安装角对其影响更明显,以此可进行导流板的气动外形优化;随着马赫数的增大,前导流板负升力及阻力增大程度相比于后导流板更为明显。

In order to reduce the instability caused by aerodynamic lift of hypersonic rocket sled, the deflectors were installed on the front and rear slipper to provide negative lift. Taking the steady-state three-dimensional viscous compressiblek-εequation as governing equation, and using Roe spatial difference format corrected by entropy and LU-SGS implicit temporal difference format,14 kinds of aerodynamic shape were calculated by means of a standardk-εtwo-equation turbulence model based on the CFD method, and the aerodynamic effect, flow field characteristics, shape optimization and flow velocity were studied. The results show that the deflector can increase the negative lift of rocket sled and enhance its stability. There are a large number of shock reflection and shock disturbance in the rocket sled flow field, which affect the density, temperature, velocity, turbulence kinetic energy and vortex line distribution of the flow field around the deflectors as well as its aerodynamic force. The size and installation angle of the deflectors will affect the aerodynamic performance, and the installation angle influences more obviously. These can optimize aerodynamic shape of deflector. With the increase of mach number, the negative lift and drag of the front deflectors increase more obviously than those of the rear deflector.