Abstract
In this study, PIV measurements in and around side-cavities of open-channel flow, i. e. groyne flow were conducted. The experimental condition is that two side-cavities were set continuously in the downstream direction with various aspect ratios. The aspect ratio of the downstream side-cavity was fixed to 2.0, whereas that of the upstream side-cavity was changed to 2.0, 5.0 and 10.0. The distance between these two side-cavities was changed to four kinds of patterns. Measurements were carried out in the downstream side-cavity. The flow direction of the time-averaged velocity was changed to the main channel direction by the effects of upstream side-cavity. The position of the shear layer changed toward the main-channel direction and the Reynolds stress and momentum distribution were increased. Furthermore, the wavelet transform was conducted about the instantaneous velocity fluctuations. As the results, at the low and peak-frequencies the convection direction of coherent vortex changed and the intensity of vortex was increased.
