Characteristics of surrounding liquid motion induced by single bubble and bubble swarm were experimentally investigated. Two types of bubble were precisely generated by bubble generator using audio speaker and hypodermic needle. PIV measurement was carried out to capture the liquid motion disturbed by bubbles. The liquid motion was analyzed from turbulence intensity defined by standard deviation of liquid-phase velocity fluctuation and bubble velocity. As a result, as increasing the bubble radius, the area of disturbance region increases in both single bubble and bubble swarm. In addition, horizontal component of turbulence intensity was obviously different.
