Dealing with Supercritical Flow in Culvert

Abstract

This paper proposes structural hydraulic models to control supercritical flows in culverts. Baffle blocks are designed to be placed in the culvert with the purpose of transforming supercritical into subcritical flow. The supercritical flow needs to be controlled so that scour will not occur at the downstream section of the culvert which is normally made of loose particles of the existing channel. The uncontrolled scour would eventually lead to failure in the embankment. Three baffle block designs were proposed in the experiments with different shapes and arrangement. It was noticed that the occurrence of baffle blocks significantly dampen the supercritical flow, for which Froude number of the approaching flow becomes smaller and velocity becomes slower. This signifies that the supercritical flow has been entirely transformed to subcritical flow. Energy losses were also computed for all designs and the results were compared.