Experimental investigation of nozzle angle effects on the brine discharge by inclined dense jets in stagnant water ambient

This study presents a series of laboratory experiments conducted on inclined dense jets from 15 degrees to 90 degrees at 15 degrees intervals, which discharge brine in a stagnant water ambient. The main geometrical properties and dilution of the flow were measured by light attenuation method. The densimetric Froude number is an effective dimensionless parameter on the inclined dense jet behavior that changes with initial velocity and the brine density. In this study, attempts have been made to investigate the relationship between the main geometric parameters of flow and dilution at return point, so a parameter is defined as the dimensionless trajectory length (R-L). The results show that dilution at the return point is somewhat related to the dimensionless trajectory length, specifically for a specific Froude number, the highest dilution occurs at about 60 degrees toward the horizontal, while the maximum dimensionless trajectory length occurs between 60 degrees and 75 degrees. Brine deposition on the seabed can create a stable stratification, which can be hazardous to the marine environment, so it is important to maximize dilution. The results of this study are presented as dimensionless diagrams that can be useful to design, estimate, and optimize the outfall systems on large scales.