高超声速气流与高能激光联合作用下金属靶体毁伤机理和多场耦合效应研究

High energy laser weapon is regarded as one of the most effective means to intercept the hypersonic missile in future battlefield. However, it should be noted that the characteristics of hypersonic target are significantly different from that of the conventional target. When the high energy laser interacts with the hypersonic target, the complex multi-physics coupling effects will be triggered and the induced failure mechanisms have not been clarified. We conducted a preliminary experiment, and the results showed that the hypersonic flow produced unneglected influence on the laser damage of the high temperature alloy target and greatly accelerated the damage process. In order to reveal the failure mechanism, the project focuses on three main issues, namely, the hypersonic flow characteristics over the cavity damage caused by the high energy laser, the multi-physics coupling damage effects when the laser irradiates the metal target in the hypersonic flow, the damage experiment method under the joint effects of the hypersonic flow and high energy laser beam, etc, which aims at making breakthroughs on the following two key scientific issues, namely, the influence rule of the laser irradiation induced damage morphology on the hypersonic flow, the fluid-thermal-solid multi-physics coupling failure mechanism of the metal target under the combined action of the hypersonic flow and high energy laser. The achievements of this project can provide theoretical and technical support for the engineering application of the high energy laser weapons applied in the hypersonic target interception.

高能激光武器被认为是未来战场拦截高超声速导弹的最有效手段之一。然而，高超声速靶体的目标特性显著区别于传统的靶目标，高能激光与之相互作用时将引发复杂的多场耦合效应，由此诱导的破坏机制尚不清楚。我们初步的实验结果发现，高超声速气流对高温合金靶体的激光毁伤产生了不容忽视的影响，起到了明显的加速作用。为揭示其中的多场耦合破坏机理，本项目拟开展高超声速来流条件下损伤凹腔流动特性、高超声速气流环境中激光辐照金属靶体多场耦合毁伤效应、高超声速气流与高能激光束流联合破坏效应实验方法等研究，以期在激光诱导损伤形貌对高超声速气流的作用机制与影响规律、高超来流和高能激光共同作用下金属靶体流-热-固多场耦合破坏机理等关键科学问题上实现突破。本项目研究成果为反制高超声速飞行器的激光武器工程化应用提供必要的理论储备与技术支持。

高能激光武器被认为是未来战场拦截高超声速导弹的最有效手段之一。然而，高超声速靶体的目标特性显著区别于传统的靶目标，高能激光与之相互作用时将引发复杂的多场耦合效应，由此诱导的破坏机制尚不清楚。我们的实验结果发现，高超声速气流对高温合金靶体的激光毁伤产生了不容忽视的影响，起到了明显的加速作用。为揭示其中的多场耦合破坏机理，本项目首先开展了激光诱导的局部损伤对高超声速流场影响机制的试验与仿真研究，结果表明圆柱凹腔损伤对高超声速流场的干扰效应明显，而且由于其特殊的几何构型，使得其内部流场结构显著区别于传统的矩形凹腔，斜向涡在封闭凹腔两侧展向造成了对称局部加热区。然后，建立了考虑烧蚀效应的流-热-固多场耦合数值分析方法，并完成了高速来流条件下的高能激光对金属薄板的流-热-固多场耦合分析，定量化地给出了不同气动效应（气动力、气动换热、气体浓度）对不同烧蚀机制（氧化、熔化、剥蚀）的定量贡献，明确了相应的烧蚀机理。结果表明，激光加速破坏的原因包括两方面，一为高超气流环境下，静压降低导致熔化速率增大，以及动压增大带来的机械剥蚀效应；二为气动热带来的结构高初始温度使得结构温度增大、材料强度降低，进一步加速了熔化和剥蚀速率。最后，搭建了高能激光束流与高超风洞联合实验平台，建立了非接触式多物理场测量系统，针对镍基高温合金（GH625）、钛合金（TC4）及铝合金等典型金属材料开展了激光毁伤实验测量与分析。结果表明，来流对激光辐照区域热效应主要通过对流换热进行，力效应包括对软化薄板的击穿效应和气流与液态熔融金属机械剥蚀效应。本项目突破了激光诱导损伤形貌对高超声速气流的作用机制与影响规律、高超来流和高能激光共同作用下金属靶体流-热-固多场耦合破坏机理等关键科学问题上实现突破，为反制高超声速飞行器的激光武器工程化应用提供必要的理论储备与技术支持。