[2F01-04] Gas-Liquid Two-Phase Flow

[2F01] Interfacial Friction in Vertical Pipes under Countercurrent Flows

(1)Flooding at the Bottom End

*Naoki Sano¹, Michio Murase¹, Toshiya Takaki¹, Koji Nishida¹, Raito Goda², Akio Tomiyama² (1. INSS, 2. Kobe Univ.)

Keywords:Vertical pipe, Countercurrent flow, Flooding, Interfacial friction factor

Flooding occurs at the square bottom end of heat transfer tubes in a steam generator under countercurrent flow conditions. In this study, we evaluated interfacial friction factors f_i in vertical pipes under flooding at the square bottom end from the pressure gradient data in air-water experiments with the diameter range of D = 6.4-152 mm, and derived a correlation for f_i as a function of the gas Wallis parameter and dimensionless diameter.