Upward Liquid Flow in a Small Tube into which Air Streams : 3rd Report, Pipe Friction I

Abstract

The pressure gradient of a bubble and slug flow after the confluence of air and liquid in a vertical small tube, and the condition of existence of a fish scale type slug flow, are investigated. For the decision of nondimensional empirical equations of pressure gradient, the following nondimensional quantities are taken into consideration, that is, supplied air -liquid ratio, liquid Reynolds number, Froude number and, Weber number. The maximum pressure gradient of the fish scale type slug flow is affected by the length and diameter of bubbles and the surface tension. It is very difficult to analyze the effect of surface tension on a two-phase flow with surface active agent solution. It is because the dynamic surface tension is very different from the static surface tension.