高超声速激波湍流边界层干扰精细结构的实验研究

Shock wave boundary layer interactions (SBLIs) occur ubiquitously in hypersonic vehicles. The researches on fine structures and flow mechanism of SBLIs are great important for the design of hypersonic aircrafts. This project proposes to experimentally investigate shock wave turbulent boundary layer interactions using Nano-tracer Planar Laser Scattering (NPLS) and Particle Image Velocimetry (PIV). The fine flow structures and velocity properties of hypersonic flow over the compression ramp in streamwise-wall-normal plane and streamwise-spanwise plane will be studied; the quantification and dynamic evolution characteristics of vortical structures will be investigated. The influences of upstream boundary layer structures and velocity fluctuations on low-frequency unsteadiness of shock motions and separated flow will be studied, and then the relationship between the upstream boundary layer and unsteady behaviors will be researched. The effect of micro-vortex generator on the compression ramp will be investigated; the influences of flow control on low-frequency unsteadiness of shock motions will be analyzed; the relationship between the reduction of the separated region and low-frequency unsteadiness of shock motions will be researched. The fine structures and the relationship between flow structures as well as flow separation and unsteady behaviors of SBLIs will be established, which is valuable for aerodynamic design of hypersonic aircrafts.

激波边界层干扰广泛存在于高超声速飞行器中，研究其流场精细结构及流动机理对高超声速飞行器的研制具有重要意义。本项目拟采用纳米示踪的平面激光散射技术(NPLS)和粒子成像测速技术(PIV)开展高超声速激波湍流边界层干扰的实验研究。研究高超声速压缩拐角流场流向与展向的精细结构和速度场特性，分析涡结构的定量特征和动力学特性；研究上游边界层的流动结构和速度脉动对激波低频振荡和流动分离位置的影响，探索上游边界层结构与流动非定常性的关系；开展微涡流发生器对压缩拐角流动控制的实验研究，分析流动控制对激波低频振荡的影响，探索分离区尺寸的减小对激波低频振荡的影响关系。通过本研究获得高超声速压缩拐角流场的精细结构，建立上游边界层结构和分离区尺寸的减小与流动非定常性的关系，可以为高超声速飞行器的的气动设计提供参考。

本项目根据国家自然科学基金“高超声速激波湍流边界层干扰精细结构的实验研究”项目要求开展。激波边界层干扰广泛存在于高超声速飞行器中；随着新一代高超声速飞行器的研制，激波边界层干扰带来的问题日益突出。本项目主要开展了高超声速条件下以压缩拐角模型、平板入射激波模型和前台阶模型产生的激波边界层干扰的试验研究，试验手段主要包括纳米示踪的平面激光散射技术(NPLS)和粒子成像测速技术(PIV)。通过研究，获得了高超声速激波湍流边界层的精细结构，分析了涡结构的尺寸、结构角及分形等定量特征和动力学特性；通过脉动压力传感器获得了激波边界层干扰上游压力脉动特性，结合流动显示结果分析了流动结构对非定常特性的影响；通过微涡流发生器对激波边界层干扰流动控制的研究，分析了流动控制带来的分离区尺寸的减小对非定常特性的影响。通过以上研究，达到了预期研究目的，实现了预期研究目标，可以为高超声速飞行器的设计提供参考。