抄録
It has been known that microbubbles, which are injected into the turbulent boundary layer, reduce skin friction, and effect of the reduction can be 80%. Therefore utilizing of microbubbles for drag reduction is expected. However, a mechanism for the reduction has never been revealed clearly yet, it is necessary to understand the mechanism for practical applications. In this study, an objective is to obtain properties of the turbulent flow field with the microbubbles to understand the mechanism of reduction, so that flow field measurements for turbulent channel flow with injected microbubbles are carried out by using PIV/LIF combined system. Capability of the measurement system and results of the measurements are discussed.