Wettability Effect on a Single Bubble Rising in Stagnant Water Contained in a Vertical Circular Pipe

Abstract

Observation has been made on the behavior of a single bubble rising in stagnant water contained in a vertical circular pipe. The inner wall of the pipe is coated with fluororesin to change its wettability. The rising velocity of a single bubble in a wetted pipe is favorably predicted by a previously proposed empirical equation. A prediction method has been proposed for the rising velocity of a single bubble rising in a poorly wetted pipe. The wettability effect disappears when the inner wall of the pipe exceeds a critical Reynolds number.