Numerical study of the flow and dilution behaviors of round buoyant jet in counterflow

Abstract

Pollutants are usually discharged into the receiving water bodies in the form of a turbulent jet or plume, and the presence of a counterflow enhances the initial dilution of the jet effluent. To understand the behaviors of jets in actual situations, a round buoyant jet issued horizontally into a uniform counterflow is simulated for different combinations of densimetric Froude number and jet-to-current velocity ratio. A two-phase mixture model is used to simulate this flow, and the renormalization group model is used to address the flow turbulence. The inter-phase interactions are described in terms of the relative slip velocity between phases. The jet features, including the trajectory of the jet centerline and the decay of the centerline velocity and the concentration, are investigated. The length scale analysis reveals the relationships between the distance and the centerline dilutions, and different flow mechanisms are revealed before and after the penetration point.