Velocity measurements were carried out in a straight open channel with a rectangular embayment. Two laser Doppler anemometers (LDA) and an electromagnetic current meter (EMC) were employed. Flow exchange between the main flow region and the dead zone, formed within the embayment, is investigated. Turbulent shear region induced at around the junction between the main flow and the dead zone is also studied. In this paper the effect of the aspect ratio of the embayment is particularly reported. The adopted aspect ratio, length/width, was 1 and 3. Circulating flow induced in the embayment is different between these cases. Mass and momentum exchange coefficients were calculated and a rectangular embayment, i.e. the aspect ratio is 3, exchanges more effectively than the square embayment case. This effectiveness for the former can be explained by the instability of the dominant circulating flow formed in the embayment.
展开▼
