微重力环境下充液航天器液体晃动特性可视化观测技术研究与设备研制

Modern space vehicles need to carry large amounts of liquid propellant in order to accomplish long and complicated space missions. Unfortunately, the accidents of spacecraft caused by the dynamic instability of liquid propellant sloshing within fuel tanks are occasionally presented. It becomes one of the main factors hampering the rapid development of the modern aerospace science and technology. The transparent propellant surfaces in the microgravity environment of space present a variety of complex shapes, which led to a severe lack of observation technology for measuring the vibration mode, the law of motion and the information of three-phase (solid - liquid - gas) contact interface, etc. Therefore, it also restricts the in-depth research of the problem of liquid sloshing under microgravity environment. This project is based on developing visual observation technology and measurement system under the low gravity environment for the study of liquid sloshing characteristics. It is committed to develop multi-scale and high sensitivity measurement techniques for three-dimensional deformation of complicated transparent liquid surfaces. Furthermore, it is difficult for the accuracy of the theoretical and numerical study of higher-order sloshing characteristic parameters to be fully verified experimentally. To solve this problem which plagued scientists for nearly 50 years, a comprehensive characterization techniques for higher-order sloshing characteristic parameters by using the vibration characteristics of liquid sloshing wave as a test criterion is proposed. Additionally, an in-situ observation technique of complex three-dimensional sloshing surface deformation characteristics and the motion law of contact line under microgravity environment are developed, and the experimental study of anti-sway damping and energy dissipation mechanism is carried out. This will provide a scientific technical support for the optimization design of anti-sway structures in the complex fuel tanks of space vehicles and is also expected to be applied to on-line monitoring for the liquid sloshing of modern spacecraft transparent tank in the future.

现代航天器需携带大量的液体推进剂以完成长时间的飞行任务，由液体晃动引发的航天器动力学不稳定事故时有发生，成为阻碍现代航天科技飞速发展的因素之一。由于太空微重力环境下透明的液体推进剂液面呈多种复杂的形状，其模态振形、固-液-气三相界面接触线位置和运动规律等的观测技术严重缺乏，限制了微重力下液体晃动问题的深入研究。本项目立足于发展微重力环境下液体晃动特性研究的加载与可视化观测技术与系统，创新发展多尺度、高灵敏度的复杂透明液面三维变形测量新方法，提出以液面波动振形特征为判据的高阶晃动特征参量综合表征技术，解决困扰科技工作者近50年的理论和数值研究中高阶的准确性难以从实验上得到全面验证的难题；原位观测微重力环境下复杂液面三维变形特征、接触线运动规律，开展防晃阻尼与能量耗散机制实验研究，将为现代航天器复杂贮箱防晃结构优化设计提供科学的技术支持，并有望应用于现代航天器透明贮箱内液体晃动的在线监测。

现代航天器需携带大量的液体推进剂以完成长时间的飞行任务，由液体晃动引发的航天器动力学不稳定事故时有发生，成为阻碍现代航天科技飞速发展的因素之一。本研究发展和提出了一系列针对透明液体液面静动态变形的测量技术和方法，如发展了透射光波前畸变分析液面变形的测量新方法，提出了结合透射条纹和散斑混合变形载体的多尺度液面变形测量方法，以及提出了基于双层信息载体的变形测量方法和透射光栅采样云纹相移技术等；建立了复杂形状贮箱内位移畸变与晃动液面离面变形之间的理论分析模型，提出了复杂贮箱内晃动液体液面变形测量方法；通过验证实验证明了发展或提出的多种液面静动态变形测量方法的有效性和可行性；基于直流电机和凸轮传统机构的转动转化为面内平动的思路设计了低频可控晃动装置，研制了常重力和模拟微重力环境下液体晃动特性研究的加载与可视化观测一体化系统；利用发展的方法和研制的实验系统，开展了常重力环境下复杂容器贮箱内一阶、二阶、三阶等高阶小幅晃动特性以及大幅非线性晃动规律实验研究，实验结果也验证了相关理论的正确性；开展了模拟微重力环境下考虑表面张力作用的低 Bond 数的液体晃动特性实验研究，以及不同防晃结构设计对液体晃动规律的影响，分析了微重力下表面张力对晃动频率、模态振型、三相接触线演化等的影响规律；此外，将发展的多种方法进一步推广，应用到了液体法拉第波的形成规律实验研究、以及探讨了在固/液/气界面上半径对漂浮粒子所受微力的影响。本研究发展的方法将为现代航天器复杂贮箱防晃结构优化设计研究奠定科学的技术基础，同时为现代航天器透明贮箱内液体晃动特性的在线监测提供可靠的技术支撑。.在本项目执行期间，相关的工作共授权国家发明专利3项、软件著作权2项，发表标注基金资助的有关SCI论文18篇。