运载火箭低温输送系统间歇泉特性及抑制方案探究

Exploration on Characteristics and Elimination Method of Geyser in the Cryogenic Propellant Feed Tube of a Launch Vehicle

为研究重型运载火箭液氧管道中的间歇泉现象并设计有效的抑制方法,调研分析了不同领域中间歇泉的研究现状及低温领域间歇泉的特点。揭示了低温推进剂管道中间歇泉的动态特性和产生机理,提出了重型运载火箭间歇泉抑制方法。研究表明:1)低温领域发生间歇泉的管道结构参数、热流输入方式、液体性质与其他领域相比有较大不同;2)减压沸腾是间歇泉产生的主要原因,弹状气泡不是低温管道中产生间歇泉的必要条件;3)间歇泉过程中会出现剧烈的压力降低和突增现象,在恶劣工况下压力波动可达兆帕量级;4)根据重型火箭的管路布局方式,可选择氦气注入或者外界热流引起循环流动的方法来抑制间歇泉。

In order to get a comprehensive knowledge of the geyser characteristics in a heavy launch vehicle and design reasonable elimination measures, the recent research results of geyser in different fields are reviewed. Transient characteristics of geyser are analyzed. The inadequacy in research on geyser in cryogenic field is pointed out. The promising elimination methods of the geyser for heavy launch vehicles are proposed. The following conclusions are drawn: 1) Compared to the geyser in other fields, the geyser occurring in the cryogenic field is different in pipe structure parameters, pattern of heat input and fluid properties. 2) The depressurization boiling is the main reason for geyser to occur, and the generation of the Taylor bubbles is not the necessary condition. 3) There would be a dramatic pressure drop and a pressure peak in the geyser process, and the pressure fluctuations could reach a magnitude of megapascals in some severe conditions. 4) The recirculation method induced by the helium injection or heat leak from the environment could be employed to eliminate the geyser in a heavy launch vehicle based on the layout of the feed tube.