Maximum Penetration of Vertical Round Dense Jets at Small and Large Froude Numbers

Abstract

An experiment was conducted to examine the maximum penetration of a dense jet issuing vertically from a round source. This flow simulates the discharge of brine solution from desalination plants and other industrial discharges into the ocean. The experiment was designed to reveal the effect of the source mass flux. The behavior of a turbulent buoyant jet from an ideal point source in a calm and homogeneous environment is controlled by two source parameters, namely the momentum flux, Mo, and the buoyancy flux, Bo. For this limiting case, the maximum vertical penetration of a dense jet, Zm, normalized by a length scale, Lm, which is proportional to Mo3/4Bo-1/2, must be constant. In agreement with previous investigations, the results of this experiment showed that Zm/Lm is constant for large densimetric Froude number jets (F> 7.0), confirming that in this regime the source mass flux has a negligible effect on maximum jet penetration. The experiment also showed that Zm/Lm was always less than the asymptotic point source solution for small densimetric Froude number jets (F< 7.0) due to the effect of source mass flux.