Efflux from a slit in a vertical wall

Abstract

A numerical solution is provided for flow of a stream of water falling under gravity after emerging from a simple slit orifice in a vertical wall. The classical free-streamline flow with contraction coefficient 0.611 applies in the absence of gravity, or as F → ∞, where F is the Froude number based on the net volume flux and the slit width. We assume here that F is finite, but find that the flow exists only for F [ges ] 0.496, with initial backflow at the upper stream surface for 0.496 [les ] F [les ] 0.578. The limiting flow at F = 0.496 has a stagnation point at the upper edge.