侧向喷流对超声速流动中支杆减阻降热特性影响的研究

Research on Effects of Lateral Jet on Drag and Heat Reduction Characteristics of Spike in Supersonic Flows

关键词:  侧向喷流  支杆  热防护系统  计算流体力学

Key words:  Lateral jet  Spike  Thermal protection system  Computational fluid dynamics

摘要:

为研究超声速流动中支杆侧向喷流的减阻降热特性，基于有限体积法求解非定常雷诺平均Navier-Stokes方程组，采用3阶MUSCL重构方法，AUSMPW+通量分裂格式，[k-ω?]SST湍流模型并耦合求解固相热传导方程，编制了计算程序并利用相关实验验证了数值方法的可靠性。在此基础上，研究了侧向喷流总压和位置对超声速流动中支杆减阻降热特性的影响，得到了壁面St数、壁面压力及气动阻力的变化规律并考察了壁面热流随时间的动态变化过程。研究结果表明:当侧向喷流位置一定时，侧向喷流总压的增大将进一步提高减阻降热性能；当侧向喷流总压不变时，随着侧向喷流位置向钝体壁面靠近，减阻降热性能明显变差，尤其当侧向喷流总压较大时，阻力增长幅度接近50%。当侧向喷流位置离开支杆底部时，气动阻力对侧向喷流总压的变化较为敏感；随着时间的推进，壁面热流密度呈现下降趋势，在2s内壁面热流密度最大降幅达到49.5%，但热流密度沿壁面分布规律未发生变化。

Abstract:

In order to investigate the characteristics of drag and heat reduction by a combinational lateral jet and spike in supersonic flows， based on the finite volume method the unsteady Reynolds-average Navier-Stokes (RANS) equations was solved by using high resolution upwind scheme AUSMPW+， 3 order MUSCL reconstruction method and[k-ω?]SST turbulence model with solving the solid state heat transfer equations. The code was developed and validated by related experimental case. Based on that， the effects of lateral jet total pressure and position were studied. Change laws of Stanton number， pressure of wall and the aerodynamic drag have been obtained and the dynamic characteristics of the wall heat flux with time is also investigated. Results show that when the position of lateral jet is fixed， the performance of heat and drag reduction all become better with the increasing of the lateral jet total pressure. The performance of heat and drag reduction become worse when the position of lateral jet gets closer to the blunt body surface as the lateral jet total pressure keeps constant， especially when the lateral jet total pressure is high， the drag increases by nearly 50%. The aerodynamic drag becomes more sensitive to the change of lateral jet total pressure when the lateral jet position is away from the bottom of the spike. The wall heat flux shows a decreasing trend with time and decreased by 49.5% in 2 seconds， but its distribution law along the wall keeps the same.