Flooding in tubes and annuli

The limitation of vertical countercurrent flow, called flooding, is important for the operation of Emergency Core Cooling Systems in Nuclear Reactors. A new flooding correlation is presented which solves the obvious contradiction between the Wallis correlation and the study by Pushkina and Sorokin concerning the scaling question at zero penetration of liquid. In addition, this flooding correlation is applicable for partial delivery in pipe and annuli experiments as long as the liquid penetrates in the form of a film along the walls.