高焓风洞内高超声速飞行器的高重频激光减阻规律研究

Wave drag is an important factor which can influnce aerodynamic performace of hypersonic vehicle. Among drag reduction method of energy depositon, laser is an effective energy source because of its excellent directivity and controllability. In this project, quasi-stationary wave will be formed by high repetition rate(100kHz) laser breaking down hypersonic flow in high-enthalpy shock tunnel. Interaction between quasi-stationary wave and shock wave in front of vehicle blunt body and phenomena of drag reduction will be studied experimentally. Through acquired experimental data, influnce on drag reduction performance of parameters of vehicle, laser, hypersonic flow will be obtained. Dimensionless factor will be extracted, and the energy similar law of drag reduction induced by laser will be disclosed. Through the research of this project, key problem of quasi-stationary wave being formed by high repetition rate laser in hypersonic flow will be solved. Process of drag reduction on hypersonic vehicle induced by high repetition rate laser in high-enthalpy will be realized, which will propose a new technology of active drag reduction on hypersonic vehicle.

高超声速飞行器的激波阻力是影响其气动性能的重要因素，能量沉积减阻技术中，激光由于方向性和可控性好等优点被认为是减小波阻的有效能量源。 本项目拟在高焓激波风洞条件下，利用频率达到100kHz的高重频激光击穿高超声速气流，形成相对稳定的准静态波，研究准静态波与飞行器钝头体前弓形激波的相互作用并使飞行器钝头体波阻减小的现象，获得可靠的减阻实验数据，得到飞行器构形参数、激光参数、气流参数对减阻性能的影响规律，并提炼无量纲因子，揭示激光减阻的能量相似规律。 通过本项目的研究，解决高超声速条件下高重频激光能量沉积形成准静态波的关键问题，在高焓激波风洞中实现高重频激光减小高超声速飞行器波阻的过程，为高超声速飞行器的主动减阻技术提出新方案。

本项目以高重频激光减阻技术为研究背景,以高焓激波风洞内的高超声速弓形激波为控制对象,开展了以下研究内容:.（1）研制基于氢氧爆轰驱动的高焓激波风洞，来流马赫数达到10，总温达到3000K，总压达到5MPa，形成了高焓高超声速来流条件；利用合束的方法解决激光的脉冲能量和重频难以同时提高的矛盾，频率达到1MHz，单脉冲能量达到400mJ；.（2）利用高重频激光击穿高超声速气流，研究在高超声速流场内形成准静态波的实验条件； .（3）将高精度光学测量技术应用于高重频激光减阻研究，精细刻画了脉冲激光与高超声速弓形激波的相互作用过程，揭示了减阻机理；.（4）研究准静态波与飞行器钝头体前弓形激波的相互作用并使飞行器钝头体波阻减小的现象，得到飞行器构形参数、激光参数、气流参数对减阻性能的影响规律；.（5）利用量纲分析方法提炼了决定激光减阻性能的无量纲因子，给出了拟合的函数关系式，并进行了典型的实验验证，结果表明无量纲能量大小、激光能量注入位置L/D、来流马赫数Ma是关键的3个无量纲因子，共同决定了高重频激光减阻性能。. 通过本项目的研究，解决了高超声速条件下高重频激光能量沉积形成准静态波的关键问题，揭示了在高焓激波风洞中实现高重频激光减小高超声速飞行器波阻的过程，揭示了激光减阻的能量相似规律，为高超声速飞行器的激光减阻新技术的形成提供了重要的研究平台和理论基础。