飞机防除冰用超材料微波生热机理及效率研究

This project proposes an anti-/de- icing method for aircraft using electromagnetic（EM） metamaterial under microwave heating. The method combines the merits of microwave heating of rapid, selectivity and volumetric heating and the merit of metamaterial absorbing incident microwave totally and converting the EM energy into heat within ultra thin thickness. The heating region can also be easily changed by changing the direction of microwave radiation with this method, which can be used to remove the ice accretion from supercooled large droplets(SLD) which may cross over the protective scope of conventional deicing methods. As the application of metamaterial in microwave heating is firstly proposed, the relevant study is not seen till now. Further more, the microwave heating mechanism, energy conversion efficiency and uniformity of thermal field distribution of the metamaterial are all different from the ordinary material’s, and have intercross complexity of EM and thermal. This project aims to the key scientific problems and plan to carry out theoretical research, EM simulation, multiphysical simulation and experimental investigations, and new understandings of these problems are expected. The research may pave a road directs to wide applications of metamaterial in aircraft anti-/de- icing and even in Engineering deicing of microwave heating.

本项目提出了采用电磁超材料微波生热的飞机防除冰方法。该方法利用了微波加热具有快速、选择性、体加热的优点以及超材料能在极薄厚度下完全吸收入射微波能量转换为热量的特点。该法还可通过改变微波辐照方向而改变加热区域，从而针对性地去除超冷大液滴结冰环境造成的飞机超保护范围结冰。鉴于超材料在微波加热应用中尚属首次，相关研究还未见报道，且其微波生热机理、能量转换效率以及热量场的分布均匀性等问题均与普通材料的不同，并具有电磁学和热物理学交叉的复杂性，故拟开展相应的理论研究、电磁仿真和多物理场仿真研究以及实验研究，得到对上述问题的科学认识，为超材料在飞机防除冰领域甚至微波加热除冰工程领域中的应用奠定基础。

在民用飞机上，为了应对高空机翼表面结冰而带来飞机安全问题，飞机上均安装有防冰、除冰装置。目前主流并具代表性的是波音787所采用的电热膜加热除冰技术。该方法是将整面机翼分成多个小块，每块做成内外绝缘层中间电热膜层的三明治结构，再给每块供配电，采用电阻性加热方法获得防除冰能力。这种方法的加工制备方法较为复杂、热传导效率低、存在电化学腐蚀风险、供配电系统较为复杂。本项目提出了超材料微波加热除冰方法。与电热法相比，本项目方法具有超材料加工制备简单、无需配电、加热效率高、速度快、体加热、无需绝缘、可大范围灵活扫描加热等优势。在此背景下，本项目开展了超材料在微波辐照下的生热机理、能量转换效率以及热量场的分布均匀性等科学问题的研究。通过项目研究，筛选出了高硅氧玻璃布聚酰亚胺复合材料为基材的超材料，采用电磁场和热量场耦合仿真的方法揭示了微波加热超材料的生热机理，依托多物理场仿真计算了微波能量到热量的转换效率，开展了微波加热超材料的实验，并直观给出了超材料微波加热呈现的宏观均匀性和微观集中性温度场分布特点。突破并完成了用于微波加热超材料除冰研究的材料选材、制备、吸波特性测量、微波加热实验、热量场和温度场计量等技术。实验中获得的有代表性的数据为：在2.25GHz处实测超材料微波反射率约-7dB，辐照微波功率60W，超材料表面微波功率密度约1.7kW/m2，超材料在约50s内温度升高了约28°，约合0.01℃/s/W。项目结果证实了超材料在微波加热方面的应用潜力，待技术成熟后可在飞机除冰、卫星天线除冰、风电叶片除冰等领域推广应用。