Laboratory experiments on the impact of a buoyant jet with a solid boundary

Model experiments are presented to show and quantify the distortions to the structures of the velocity field of a plane, negatively-buoyant jet caused by the impact of the jet with a bottom boundary. The techniques of shadowgraph and particle tracking are used to monitor continuously the behaviour of the perturbed flow and the two-dimensional velocity field within the jet, for a range of momentum and buoyancy fluxes and fluid depths. The shape of the disturbance field close to impact is characterised by a pair of vortices displaced symmetrically from the centreline of the incident jet. The height reached by the associated vortex pairs after the impact with the solid boundary is shown to have clear dependence upon the Richardson number of the buoyant jet. The distortion of the jet centerline velocity decay within the impact zone is discussed.