新型主动式激光测温法在高超声速气动热试验中的应用探索

The accurate measurement of the material surface temperature in the hypersonic aerodynamic thermal test plays a vital role in the precise thermal protection system design of the hypersonic vehicles. Conventional, passive, radiation thermometry is used in many cases but is often subject to serious systematic errors resulting from poorly characterized emissivity. Due to lack of accurate material emissivity data and the emissivity usually unstable during the aerodynamic thermal test, developing novel radiation thermometry methods is imminently required in the hypersonic aerodynamic thermal test. In this proposal, a novel active laser pyrometry (ALP) is proposed. The ALP is a photo-thermal radiometry technique, combining radiation thermometry with high power, infrared laser technology. The ALP technique detects the small modulations in thermal radiances at wavelengths 1 and 2 due photo-thermal heating of the target induced by two modulated lasers at wavelengths 2 and 1 respectively. The ratio of these two modulated thermal radiances is a function of temperature and is independent of emissivity. The non-ideal effect of the nonlinearity of the detectors and the extraneous background radiation will be studied by theoretical and experimental investigation. Finally, the exploration of applying ALP in the hypersonic aerodynamic thermal test will be carried out in the hypersonic wind tunnel.

高超声速气动热试验中材料表面温度的准确测量是制约航天器精细化热设计和防隔热技术发展的瓶颈之一。由于传统的辐射测温技术对于材料的发射率的准确性存在很强的依赖性，而航天材料又面临高温发射率基础数据匮乏及在试验中动态变化的困境，发展新型辐射测温技术成为高超声速气动热试验中的迫切需求。本项目提出了一种新型的主动式激光测温方法。基于双波长激光与材料相互作用下的光热效应，采用反序波长探测和相敏检测技术，开展不依赖材料发射率的主动式激光测温探索研究。基于复杂边界条件下激光作用材料光热效应模拟，优化激光光源、探测系统、光学成像系统参数。理论研究与实验手段结合，研究传递辐射介质干扰、光电探测器非线性等不确定度来源与贡献。依托高超声速电弧风洞，开展主动式激光测温法在模型表面温度测量的应用探索。

传统的辐射测温技术面临对于材料的发射率的准确性存在很强的依赖性的固有局限性，本项目以航空航天领域国家重大需求为牵引，聚焦空天领域材料表面真温新型测试技术，在科学基金的支持下，在主动式激光测量方法及溯源技术上取得了重要的原创性成果突破。建立了基于双波长激光光热效应诱导、反序波长相敏探测的主动式激光测温理论新系统，首次在我国实现空天特种材料表面温度免发射率高精度测量能力。研究成果应用于空天领域我国多个重大工程高温特种功能涂层研发、上机定型，取得了显著的社会经济效益，推广应用前景广阔。