Abstract
In order to clarify the effect of bubble passage to wall-shear stress in air-liquid two-phase flow in a horizontal duct, instantaneous wall-shear stress and liquid-film thickness by using conductance probe were simultaneously measured. With increasing of gas flow-rate, time-series of liquid-film thickness and wall-shear stress changed around bubble's nose, and reduction ratio of the wall-shear stress slightly decreased. The time-average wall-shear stress was affected by the bubble's wake and liquid holdup which were obtained by pictures. Time-average wall-shear stress became lower than that of the single-phase flow when the liquid holdup around top-wall surface was lower than 60%.
