HYDRODYNAMIC EFFECTS OF BED CONFIGURATION IN EMBAYMENT ON FLOW PATTERNS AND RELATED TURBULENCE TRANSPORT IN OPEN-CHANNEL FLOWS WITH SIDE CAVITY ZONE

In this study, we focused on side-cavity zone in open-channel flows, and effects of sedimentation on horizontal circulation structure and related mass-exchanges were considered on the basis of the measured data obtained by the laboratory experiments. The both of primary gyre and secondary one are observed in the flat-bed and downward slope conditions, and in contrast, the only primary gyre appears in the upward slope condition. It was found that these formations of the horizontal circulations play significant roles on the mass transfer properties between the mainstream and the embayment. Furthermore, a new physical model which predicts a mass transport velocity reasonably was developed by referring to a surface renewal model.