水深と流速の同時ステレオ計測による開水路サイドキャビティ流れの振動モード解析

抄録

The open-channel flow with a side cavity is known to exhibit various types of free surface oscillations within the cavity zone. A typical type of oscillation observed is similar to the one by a seiche generated in a closed box; however it has been reported that other types of oscillation can also be generated depending on the geometrical and hydraulic conditions. In this paper, a novel technique for measuring two dimensional water surface variations as well as surface velocity distributions is developed and the technique is applied to the flow at the side cavity zone with various aspect ratios of the side cavity. The water surface variation is analyzed by the POD technique while the velocity field is measured simultaneously by the PIV method. It was found that the surface oscillation can be categorized into four types and the water surface oscillation within the cavity zone is closely correlated with velocity variation.