CASE STUDY ON CONVEYANCE IMPROVEMENT OF INVERTED SHIPHON BY THREE DIMENSIONAL FLOW ANALYSIS

Abstract

 This study conducted numerical simulation of 3-dimensional flow around the inverted syphon, in which upstream water level exceeds a design level. The results showed generation of a separation vortex near the top wall of the upper reach of culvert and indicated possibility of a huge head loss at this portion. As the result of comparative simulation of several proposals for improvement, we found that water conduction capacity of the inverted syphon was improved greatly, by chamfering the top wall of culvert inlet, at this chamfer, a part of upstream transition near the culvert was modified to closed type and its cross sectional area of flow was reduced gradually toward the culvert.