Numerical Investigation of Inverse Curvature Ogee Spillway

Design of water structures and their segments including spillways play an important role in water resources managementand agricultural activities. In the the linear body part of an ogee spillway, for speeding up the flow rate, the flow should betransferred to the stilling basin by inverse curve so that the water energy can be reduced. This study aims to evaluate theeffect of the inverse profile curvature on the pressure of spillway surface using Fluent software. For this purpose, fivedifferent curvatures of inverse profile were considered to be equal to no-curvature (zero), 1, 1.5, 2 and 2.5 of the spillwaydesign head. The results indicated that by increasing the curvature radius, the maximum pressure dramatically reduced.And for this purpose, some relationships were given to predict the pressure reduction. Pressure increment in zero curvatureis caused by sudden collision of flow lines and turbulence caused by it. By increase in inverse profile curvature, theturbulence is created in flow lines and the maximum pressure shows a lower value than before. In general, there was littlechange in the average absolute pressure.

Keywords:

Numerical Modeling , Ogee Spillway , Pressure Profile , Inverse Curvature