微重力下两相控温型储液器内气液界面仿真分析

两相控温型储液器对机械泵驱动两相流体回路的稳定运行起到关键作用，而储液器内部气液分布状态是其控温性能的决定性因素之一。在轨微重力条件下，储液器内两相流动特性与地面状态差别巨大，这将给储液器的设计带来较大难度。针对两相控温型储液器在轨微重力下的两相工质分布特性，通过计算流体力学（CFD）方法对其内两相流动行为进行数值模拟。通过使用连续表面张力模型计算表面张力，使用多相流计算的流体体积分数方法对两相控温型储液器内气液界面形态的发展进行了追踪预测，并与理论解进行对比，结果吻合一致。通过对两相控温型储液器在不同Bond数、接触角、工质充灌量等参数下的仿真分析，得到了不同条件下储液器内气液运动及分布情况，结果表明:两相控温型储液器内气液界面状态与储液器尺寸、壁面浸润性、工质充灌量相关。研究结果可以为微重力下两相控温型储液器内气液界面的控制提供理论依据，并能指导储液器研制及在轨应用。 

Numerical analyses of liquid-vapor interface in two-phase thermal-controlled accumulator under microgravity condition

Two-phase thermal-controlled accumulator plays a vital role in mechanically pumped two-phase loop system. And the distribution state of liquid and vapor is one of the key factors that decide the temperature control performance of the accumulator. The distribution state of fluid in accumulator under on-orbit microgravity condition is significantly different from that on ground, which brings great difficulties to the accumulator design. In order to study the two-phase medium distribution characteristics of accumulator under on-orbit microgravity condition, Computational Fluid Dynamics (CFD) method was used to simulate the two-phase flow behavior. The continuum surface force model and volume of fluid method were adopted to calculate the surface tension and track the liquid-vapor interface shape, respectively. By comparison between simulation results and theoretical solution, it shows that the results are consistent. Several influence parameters, including different Bond numbers, contact angles and filing ratios, were studied, the movement and distribution characteristics of the two-phase medium were obtained.The results indicate that the liquid-vapor interface shape is related to the size, wall wettability and medium filling ratio of accumulator. The results presented in this paper can provide theory basis for the control of liquid-vapor interface in accumulator, and can guide the research, development and on-orbit application of accumulator.