高超声速流动多物理效应对美国航天飞机气动力影响研究的回顾

Review on influence of the multi-physical effects in hypersonic flow on aerodynamic characteristics of the United States space shuttle

  • 摘要: 临近空间高超声速流动往往存在真实气体效应、稀薄气体效应和粘性干扰效应等多种复杂的物理、化学和流动现象。围绕高超声速绕流中多物理效应这一主题,对美国航天飞机高超声速气动力研究的工作按飞行前与飞行后两个阶段进行了回顾。在飞行前阶段,主要介绍了气动力外推参数的研究和不确定度研究的内容,确定了以第三粘性系数V'作为气动力特性外推参数,以及给出了气动力不确定的计算方法;而在飞行后阶段,主要介绍了飞行试验数据与预测数据的对比、纵向配平异常分析和外推方法,给出了初步的由风洞数据外推到飞行数据的外推方法,确认了真实气体效应对航天飞机气动特性影响,但是否对舵面效率产生影响没有达成一致的结论。而后,作者讨论了避免纵向配平异常的可能性、体襟翼效率数值计算与试验的差异、气动力不确定度研究和建立飞行试验/风洞试验/数值计算数据共享机制四个方面的问题。另外,早期的研究文献提到了航天飞机在再入过程中这些效应是同时存在的,在当时的研究条件下难以区分各自对气动力特性的影响,后来的研究文献也没有着力于研究其耦合影响效应对航天飞机气动力特性的影响,这为下一步研究再入飞行器高超声速绕流流动的多物理效应提供了指引。

     

    Abstract: Near-space hypersonic flow usually has concomitant circumstances with multiple complex physical, chemical and fluid mechanicsuch as real gas effects, rarefied effects, and viscous interactions. Regarding the topic of multi-physics phenomena in the hypersonic flow past complex lift-body configurations, the studies on the hypersonic aerodynamic characteristics of American shuttle orbiter were briefly reviewed for the phase of pre-flight and post-flight, respectively. For the pre-flight phase, the studies were introduced with respect to extrapolating parameter of the aerodynamic data and the uncertainty quantity. Hypersonic viscous parameter was employed as the extrapolating factor of the aerodynamic characteristics, and the computational method was introduced for the uncertainty quantity of the aerodynamic forces. The introduction of the post-flight phase included the comparison between the predicted data and the flight tests, the longitudinal trim anomaly analysis, and the extrapolating method for the flight data. The preliminary method, extrapolating the wind-tunnel data to the flight data, was surveyed. The influence of the real gas effects was identified on the aerodynamic characteristics; however, it is still uncertain that the real gas effects have influence on the control surfaces efficiency. Finally, four issues, i.e., the probability of avoiding longitudinal trim anomaly, the differences of the body-flap efficiency between the calculations and the experiments, the studies of the aerodynamics uncertainty with various approaches, and the establishment of a sharing system for data from the flight tests, the tunnel tests and the CFD are discussed. In addition, it is mentioned in the early studies that the multi-physics phenomena co-exist during the space shuttle reentry, and it is difficult to discern the individual effect on the aerodynamic characteristics under the research conditions at that time. In the late studies, it has not been focused on that the coupled effects of these phenomena on the aerodynamics characteristics of the space shuttle. This lack of investigations provides a further research field for the studies of multi-physics phenomena.

     

/

返回文章
返回