智能可变形飞行器关键技术发展现状及展望

Development status of key technologies and expectation about smart morphing aircraft

智能可变形飞行器是当前航空航天飞行器研究领域的一个热点,是最有可能带来航空航天技术变革,产生颠覆性影响的领域之一,因此受到国内外的广泛关注。本文首先指出飞行器可变形的需求主要来源于如下几个方面,即:1)未来飞行器的飞行空域、速域不断扩大,固定外形可能无法满足不同飞行工况对飞行器气动和飞行性能的需求;2)单架飞行器实现多个飞行使命和任务,可能需要飞行器在执行不同飞行任务时具有不同的气动外形;3)提升现有飞行器的气动总体性能,要求其在各个飞行阶段,通过调整气动外形,使其始终保持优良的气动和飞行性能。介绍了现代意义上的智能可变形飞行器所包含的“变形”和“智能”两方面的含义,其中“变形”是指不同空间尺度(局部、分布、整体)和时间尺度的连续变形,涵盖的范围很宽。按照变形尺度和实现的功能将其划分为三类,即:局部变形(小变形)、分布式变形(中等尺度变形)、整体式变形(大尺度变形)。按照实现方式将其划分为两类:机械式变形和基于智能材料结构的变形。并指出当前这个领域的所谓“智能”基本都限制在智能材料或结构、智能控制等较为单一的领域,距离理想的智能变形有很大差距。本论文的论述重点放在可变形技术所涉及的基础科学问题和关键技术。第二,从1903年人类第一架依靠柔性变形机翼实现控制的莱特兄弟的带动力飞行器起,到20世纪六七十年代以F14为代表的变后掠翼技术,至近些年来在湾流III飞机上成功实现飞行演示验证的连续变后缘弯度技术,系统地介绍了可变形飞行器的发展历程。第三,分别从可变形飞行器设计所面临的关键技术和可变形飞行器两大基础科学问题及技术瓶颈问题的角度,系统地介绍了可变形飞行器所面临的关键问题和国内外研究进展。从设计的角度看,主要问题在于:智能可变形飞行器需求分析和概念研究,智能可变形飞行器总体和分系统设计技术。从基础科学问题和瓶颈技术的角度看,主要问题在于两个方面,即:可变形飞行器气动、飞行力学和飞行控制,变形结构、驱动与变形控制。第四,针对智能可变形飞行器的内涵、可变形的技术指标、变形材料与结构以及效费分析等几个方面进行了有益的探讨。最后对智能可变形飞行器技术的未来发展进行了展望,指出智能可变形飞行器技术是螺旋式发展的,一方面需要开展广泛系统的基础理论和关键技术探索研究,从基础做起;另一方面需要从工程化的角度梳理可变形飞行器一类或几类较为明确的背景需求,以牵引该领域的有序快速发展。

Smart morphing aircraft has already been a hot point of the aeronautics and aerospace research,which is one of the most possible domains that should bring the revolutionary influences to the development of the aeronautics and aerospace technologies. At first the necessaries about the smart morphing aircraft are pointed in this paper: 1) As the scopes of the altitude and the velocity of future aircrafts increase widely, the conventional rigid configuration may not satisfy the requirements of the aerodynamic and flight characteristics under different flight conditions;2) For the multiple flight missions and tasks achieved by a single plane, it may be necessary for aircraft to alter the aerodynamic configuration in performing different missions;3) In order to improve the overall aerodynamic performance of the existing aircraft, it is required to maintain excellent aerodynamic and flight performance through adjusting aerodynamic shape in all flight stages. This paper introduces the meanings of “morphing” and “smart” in the modern sense of smart morphing aircraft, in which “morphing” refers to the continuous deformation of different spatial scales (local, distributed, global) and time scales, covering a wide range. According to the deformation scale and function, it can be divided into three categories: local deformation (small deformation), distributed deformation (medium-scale deformation), and integral deformation (large-scale deformation). It can be divided into two types according to the way of realization;mechanical deformation and deformation based on smart material structure. It is also pointed out that the so-called “smart” in this field is basically confined to a single field such as smart materials or structures and intelligent control, which is far from ideal smart morphing.So this paper focuses on the basic scientific issues and key technologies involved in morphing technology. Secondly, from the first Wright Brothers powered aircraft controlled by flexible deformable wings in 1903 to the variable swept wing technology represented by F14 in the 1960s and 1970s, to the successful demonstration of continuous variable rear-edge curvature flight on Gulf Stream III aircraft in recent years, the development process of the morphing aircraft is systematically introduced in this paper. Thirdly, the key problems and research progress of morphing aircraft are systematically introduced from the point of view of the key technology and the bottleneck of deformable aircraft design. From the design point of view, the main problems include requirement analysis and conceptual research of the smart morphing aircraft, design technology of overall and subsystem of smart morphing aircraft. From the perspective of basic science and bottleneck technology, the main problems lie in following aspects: aerodynamics, flight dynamics and flight control of morphing aircraft, morphing structure, drive and morphing control. Fourthly, the connotation of smart morphing aircraft, morphing technical indicators, morphing materials and structures, and cost-effectiveness analysis is discussed. Finally, the future development of smart morphing vehicle technologies is prospected, and it is pointed out that smart morphing aircraft technology is spiral development. On the one hand, we need to carry out extensive and systematic research on basic theory and key technology, starting from the foundation;on the other hand, we need to sort out the background requirements of one or several types of morphing aircraft from the engineering point of view, in order to tract the orderly and rapid development of this field.