Effects of surfactants on bubble-induced turbulence

We use experiments to explore the effect of surfactants on bubble-induced turbulence (BIT) at different scales, considering how bubbles affect flow kinetic energy, anisotropy and extreme events. To this end, high-resolution particle shadow velocimetry measurements are carried out in a bubble column which is generated by swarms rising water for two diameters (3 4 mm) moderate gas volume fractions (0.5 %–1.3 %). tap as base liquid add 1-Pentanol an additional surfactant with varying bulk concentration, leading shapes surface boundary conditions. The results reveal that increasing BIT increases strength, even though given size rise more slowly surfactants. also find level enhanced concentration same size, smaller generate stronger flow. Concerning intermittency quantified normalized probability density functions fluid velocity increments, our indicate values increments become probable decreasing cases low void fraction, while much weaker larger higher fractions.