膜盒贮箱推进剂补加过程的建模与仿真

推进剂在轨补加是确保空间站长期工作的重要条件。为了使补加工作顺利实施,需要对推进剂补加过程进行专门的研究。航天器常用推进剂如一甲基肼、四氧化二氮等有剧毒,地面模拟补加试验常采用无毒的模拟工质。但由于两种物质的物性参数存在差异,导致模拟的补加过程和效果与实际情况有差异。文章参考国外空间站补加系统构成形式和补加过程,建立膜盒贮箱推进剂补加过程的数学模型,通过将仿真结果与地面试验数据对比验证了数学模型的准确性。进一步对两种推进剂的补加过程进行仿真分析,并与纯净水补加数据对比。结果表明:液体工质的体积流率与密度存在反比关系,即一甲基肼的补加速率高于纯净水,四氧化二氮的补加速率则低于纯净水。

Simulation and analysis of propellant refueling process of membrane tank

Propellant refueling is necessary for the long-term operation of space stations. Refueling of the propellant tank is a key process since it relates to both the cargo spaceship and the space station, besides, there is liquid propellant flowing between two spacecrafts. Many propellants are toxic, however, the flow experiments on the ground usually use nontoxic liquid instead of toxic propellant in case of leakage. Because the physical characteristics of the nontoxic liquid are different form those of the real propellants, their flow properties are also different. In this paper, a numerical model is built for the refueling course of a propellant tank, and the simulation results are compared with the experimental data using pure water, in order to validate the accuracy of the numerical model. The refueling courses of real propellants, MMH and MON-1, are investigated and compared to that of pure water. It is found that the volume flow-rate of MMH is higher than that of pure water, while that of MON-1 is lower than that of pure water.