Negatively buoyant jets at low Froude numbers in a co-flow

Experiments on inclined negatively buoyant jets discharging at low densimetric Froude numbers into a co-flow were carried out. The spread of the jet was observed by flow visualisation techniques. The results include three length scales of the jet's trajectory: the maximum penetration depth, the horizontal distance from the source to the locus of maximum penetration depth and the horizontal length from the source to the impact point. Empirical equations that express dimensionless geometrical length scales of the jet in terms of the densimetric Froude number, velocity ratio and angles of inclination were derived. The maximum penetration depth occurred at vertical discharges, whereas the maximum horizontal distance from the source to the impact point and the maximum trajectory length were obtained at 45° and 60° inclinations, respectively. The results were applied to the diffusion of inclined negatively buoyant jets in shallow water streams.