ON-ORBIT EXPERIMENTAL AND NUMERICAL STUDY ON THE EMPTYING PROCESS OF TANK MODELS

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.