板式贮箱排空过程的在轨实验和仿真研究
ON-ORBIT EXPERIMENTAL AND NUMERICAL STUDY ON THE EMPTYING PROCESS OF TANK MODELS
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摘要: 板式推进剂贮箱的排空性能决定了推进剂的利用率, 同时排空过程推进剂质心的变化会影响贮箱乃至卫星质心的稳定, 因而是值得关注的. 文章提出了一种球形全管理板式贮箱的设计, 包含4片导流板、4片小蓄液片和一个中心柱. 在中国空间站上开展了贮箱模型的流体输运和排空实验, 并建立贮箱的非结构网格模型, 开展匹配空间站排空实验的仿真分析, 通过实验和仿真的液体流动速度对比验证了网格模型和仿真方法的准确性. 基于该网格模型, 开展微重力下排空过程仿真、微重力下稳态气泡形貌仿真和机动加速度下排空过程仿真, 展现了气泡形貌受板式结构尤其是中心柱的影响在单侧气泡和环形气泡间的转变, 发现在排空过程中推进剂质心的跳变, 揭示微重力下贮箱形成环形气泡的条件, 机动加速度下的排空仿真显示该贮箱模型排空率高达99.95%, 验证了该型流体管理装置的排空性能. 文章的实验和仿真研究验证该型板式贮箱具有良好的流体管理性能, 对于含有中心柱的全管理板式贮箱的流体界面与气液分离性能研究也具有重要的借鉴价值, 这些成果和发现对空间流体管理、板式贮箱设计和卫星姿轨控策略的制定具有重要参考意义.Abstract: The emptying performance of plate propellant tanks determines the utilization rate of the propellant. And the variation of the propellant's centroid during the emptying process is noteworthy, as it can affect the stability of the tank's and ultimately the satellite's centroid. In this paper, the design of a spherical fully-managed plate tank model is proposed, which includes four guide vanes, four small liquid storage vanes, and a central column. The fluid transport and emptying experiments in the tank model are carried out aboard the Chinese Space Station. And the unstructured grid model of the tank is established, and numerical simulation matching the emptying experiment is carried out. The accuracy of the grid model and the simulation method is verified by comparing the liquid flow velocity of the experiment and the simulation. Based on the grid model, the simulation of emptying process under microgravity, the simulation of static bubble morphology under microgravity and the simulation of emptying process under maneuvering acceleration are carried out. It demonstrates the transition of bubble morphology between unilateral bubble and annular bubble, influenced by the plate structure, particularly the central column. The jump of propellant mass center during evacuation is found. The conditions for forming annular bubbles in the tank under microgravity are presented. The emptying simulation under maneuvering acceleration showed that the emptying rate of the tank model is up to 99.95%, which verified the excellent emptying performance of this kind of propellant management device. The experiment and simulation study in this paper verifies that this type of plate tank exhibits excellent fluid management performance, and it also provides valuable insights for studying the fluid interface and gas-liquid separation performance of fully-managed plate tanks with central columns. These results and findings have important reference significance for fluid management in space, plate tank design, and satellite orbit control strategy formulation.