A numerical study of confined wall jets in a shallow basin

Abstract

A numerical study was conducted to investigate the effect of confinement on wall jets in a rectangular water basin using a slot inlet. The inlet slot creates a wall jet on the bottom of the basin with a recirculation zone on top of it. The classical wall jet behaviour is observed only up to the centre of the recirculation zone, beyond that point the momentum flux is not conserved and the wall jet behaviour is lost. Empirical expressions are developed to estimate the velocity decay and the jet spreading rates, and the maximum wall shear stress. The two outlet types and their location did not affect the wall jet and the recirculation zones, if the outlet is placed at a distance greater than the normal extent of the recirculation zone.