Abstract: To investigate the atomization characteristics of liquid injection in space,a simulated vacuum system was built, and the influence of saturated vapor pressure, nozzle diameter, Reynold number and dissolved gas on flash evaporation was studied. The experimental results show that the intensity of flashing which is the dominant breakup mechanism in vacuum, is determined by saturated vapor pressure. Nozzle diameter has an important effect on the atomization. The influence of diameter on liquid injection in vacuum can be divided into several aspects:the state of flow, the turbulence intensity and the period of bubble growth. Reynold number of the jet affects atomization under space environment from three aspects:outlet velocity, flow state and flash evaporation. Dissolved gas considerably influenced the spray characteristic of liquid jet in vacuum via the unstable growth and micro-explosion of bubbles.

Key words: Space environment; Flash evaporation+ ; Atomization characteristic; Experimental study

摘要： 为了深入研究空间环境下液体工质的喷射雾化特性,搭建了空间环境模拟实验系统,综合研究了真空环境下饱和蒸汽压、喷嘴直径、雷诺数和溶气等对液体射流雾化特性的影响。试验结果表明:闪蒸是真空环境下射流雾化的主要因素,射流雾化过程中闪蒸强度主要由工质饱和蒸汽压决定；喷嘴直径主要通过三方面的影响对射流雾化起作用:流动状态、湍流强度和气泡生长周期；雷诺数对真空雾化的影响主要涵盖以下三点:出口速度、流动状态和闪蒸过程；溶气对射流雾化有明显的影响作用,影响途径是通过气泡的不稳定生长和微爆作用。

关键词: 空间环境;闪蒸⁺ ;雾化特性;实验研究 