Abstract
In this study, experiments in two intersecting ducts with a circular perforated zone are performed to investigate secondary flow and mixing in the perforated zone when changing the conditions of the intersecting angles and the upper water levels. The flow pattern in the perforated zone is visualized by the particle tracing method and the LDV. The flow rates in the downstream ducts are measured by hydrometry. Colorimeters, which have been used with color video images to analyze the visual field of complicated scenes, such as landscapes and building interiors, are used here to examine mixing. The characteristics of the secondary flow, the resistance and the mixing process in the perforated zone are clarified.
