【作者】 魏月兴；

【导师】 陈小前；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2013， 博士

【摘要】 如何进行推进剂管理是航天器贮箱设计必须考虑的关键问题。本文针对航天器在轨加注的需求，以板式表面张力贮箱的推进剂管理为背景，采用了理论分析、数值模拟和物理实验相结合的手段，重点研究了微重力条件下推进剂管理过程中的流动特性，包括表面张力驱动的流动理论、推进剂的定位过程、加注过程以及排出过程，初步建立了可用于推进剂管理过程的理论体系，为可在轨加注板式表面张力贮箱的设计提供参考。论文主要工作如下：（1）表面张力驱动的流动理论与实验研究。对液面分布的基本方程进行了分析，确定了完全失重条件下圆柱形容器内部液面的分布形式；建立了表面张力驱动流动的控制方程并求解，并与落塔实验数据进行对比，对毛细上升的动态过程进行了分析；（2）贮箱内推进剂定位的流动过程分析。基于流体运动的连续性方程，建立了内角自流控制方程，并利用自相似方法进行了理论近似求解，得到了二阶精度的理论解。在此基础上，利用毛细实验和落塔实验对理论计算结果进行了验证，并对误差进行了分析。根据内角自流的理论计算结果，完成了推进剂管理装置的导流板布局设计；（3）贮箱加注过程的入流稳定性分析。根据贮箱内射流的压强平衡方程，建立了稳态射流的控制方程，对方程进行求解并分析了贮箱相关参数对射流稳定性的影响；通过对落塔实验数据的回归分析，得到了涌泉高度与填充高度、Weber数和Bond数之间的近似关系，为分析贮箱入流的涌泉高度提供了参考；（4）贮箱推进剂排出过程的液面稳定性分析。基于Young-Laplace方程和动量方程，建立了内角过流一维稳定性控制方程，并通过Newton非线性方法求解该方程，得到沿流动方向的液面高度、曲率和速度的变化；利用数值计算方法对内角过流问题进行了三维仿真计算，仿真结果表明流动在液面达到最低点以后将会出现流动分离，存在附加压强损失；利用微重力落塔实验数据对计算结果进行了验证；（5）内角过流液面特性的微重力实验研究。根据落塔实验结束时内角流道中液面轮廓线的收敛性和液面上最低点的位置变化，提出了对超临界流动和亚临界流动的判定方法；对气泡的注入进行了初步的实验研究，实验发现，气泡的注入将使液面趋于稳定，气泡的运动轨迹与注入位置密切相关。论文通过理论分析、数值模拟和落塔实验等手段，对微重力条件下推进剂管理过程中的流动特性进行了深入研究，丰富了流动理论的研究内容，拓展了理论和实验方法；论文的研究为可在轨加注板式表面张力贮箱设计提供了重要支持，具有较强的理论意义和工程应用价值。更多还原

【Abstract】 Propellant management is significant in the design of the tank for the aircraft. Thiswork is on the background of the propellant management in the orbital refueling tank.It mostly focuses on the flow in the tank under microgravity. The thesis employs boththe analytic and experimental methods to study the basic flow theory with capillarity,the orientation process, the inflow process, and the exclusive of the propellant. It buildsa theory that can be used in the propellant management process, and provides multipletools for the design of the vane type refueling tank. Main work of the thesis are:(1) The fundamental governing equation for the free surface in a tank under micro-gravity and the theory of capillary rise. The Young-Laplace equation is explained withthe view of force balance. Meanwhile, the governing equation for the free surface in acylinder tank is solved; the theory of capillary rise is analyzed, and the equation is alsosolved. The theory is verified by the drop tower experimental data extracted from otherwork.(2)Theanalysisoftheorientationoftheliquidinthetank. Thegoverningequationisderivedfrom the flow continuity equation. A second order theoretical solution isobtainedby using the self-similar approximation method. Both the capillary experiments and thedrop tower experiments are used to verify the theory. The errors between the theory andthe experimental data are contributed to the change of the flow resistance in the flow.Furthermore, the theory is used to select the vanes in a tank to get a maximum flow ratewhile reducing the total mass.(3) The inflow stability during the refueling in the tank. The governing equation ofthe stable jet flow is derived by the pressure balance equation. Theoretical solution isused to analyze the influence of the jet parameters on the stability of the inflow. The ex-perimental data are analyzed by regression method. An approximated relation is obtainedbetween the geyser height and the filling height, Webber number as well as Bond number.This relation can be used for the tank design in applications.(4) The stability of the free surface during the exclusion of the propellant. The1-dimensional governing equation of the stability is derived from the Young-Laplace equa-tion combined with the momentum equation of the flow. Numerical method is used tosolve the equation to get the variation of the height of the free surface, the curvature, and the velocity along the flow path. Meanwhile,3-dimensional simulation of the forced flowin the channel is studied. The simulation finds that flow separation could occur after theflow pass though the lowest point of the free surface, which adds pressure loss to the flow.The drop tower experimental data are used to verify the theory as well as the simulation.(5) The experimental study of the forced flow in the channel. In the drop towerexperiments, the flow is classified as subcritical, supercritical, critical and super highspeed flow according to the development of the free surface. The flow type is identifiedby the convergence of the surface contour and the changing of the lowest point of thesurface; the experiments also found that the flow was influenced by both the oscillationof the flow and the flow development. Furthermore, the experiments also studied theimpact of the bubble injection on the flow. It showed that the bubble can stabilize theflow. The movement of the bubbles are influenced by the position of injection.This work develop a deep study on the flow of the propellant under microgravity byanalytic and experimental methods. It explores new areas of the study of the flow theoryand provides more methods for the study itself. This work could be used in the design ofthe refueling tank for the propellant management device.更多还原