Jet Discharge into a Fluid with a Density Gradient

Turbulent liquid jets (the primary fluid) discharging vertically upward into a liquid of greater density having a density gradient (the secondary fluid) are considered. The investigations were performed with a hydraulic model that simulated some of the conditions common at southern California ocean outfalls, with primary fluids of densities equivalent to those of sewage and secondary fluids of densities equivalent to those of receiving waters. The major purpose of the study was to determine under what conditions of density gradient in the secondary fluid the primary-secondary fluid mixture (corresponding to a sewage field) would spread at the surface, beneath the surface, or in both these areas. It was found that the field location could be predicted using modified equations for jets discharging into homogeneous secondary fluids.