2019

Investigation of appearance and intensity of geyser phenomenon in a vertical cryogenic pipe

H.W. Maoa, Y.Z. Liab, L. Wanga, J.J. Wanga, F.S. Xiea
aInstitute of Refrigeration and Cryogenic Engineering, Xi’an Jiaotong University, Xi’an, 710049, China
bState Key Laboratory of Technologies in Space Cryogenic Propellants, Beijing, 100028, China

摘要：

Geyser is a complex two-phase flow instability phenomenon and could be destructive to the engineering equipment while reaching a sufficient intensity. In order to study the geyser appearance and intensity characteristics of geyser in a cryogenic propellant pipe, a numerical investigation is conducted based on Volume of Fluid (VOF) method. For a quantitative expression of geyser appearance, two new dimensionless parameters, namely eruption intensity and refilling intensity, are proposed to describe the amplitude of geyser. The effect of aspect ratio on geyser is thoroughly investigated for two different changing ways and then the performance of Murphy curve is assessed. The results indicate that the flow and boiling regime in a bottom closed cryogenic pipe could be divided into four types, namely natural convection, stable boiling, weak geyser, and strong geyser. The incubation stage occupies more than 90% of the whole geyser period. Moreover, it is found that a single aspect ratio parameter could not distinguish the occurrence or the intensity change of geyser. The different impacts occur when the aspect ratio changes with the pipe length or diameter separately. Under the condition of the aspect ratio raised by the pipe length increasing, the geyser intensity continually increases. However, the geyser intensity increases firstly and then decreases when the aspect ratio raised by the pipe diameter decreasing.