Author(s): Danial Goodarzi; Abdolmajid Mohammadian; Sina Tahmooresi

Linked Author(s): Majid Mohammadian

Keywords: Buoyant jet; Computational fluid mechanics; Stratification; Large eddy simulation; Turbulence

Abstract: An efficient outfall system design can minimize wastewater discharge impacts and reduce environmental risks. This study investigates jet Reynolds number, fluid density, and ambient stratification effects on mixing and transport processes, focusing on high densimetric Froude number discharges in linearly stratified crossflow ambient. The Large Eddy Simulation turbulence model is utilized for solving water flow governing equations, applying the Boussinesq approximation for buoyancy forces. Eight cases with linear ambient stratification and various crossflow velocities and densimetric Froude numbers are examined. The findings of this research reveal the combined influence of jet densimetric Froude number and crossflow velocity on jet development in a stratified environment. The crossflow velocity exhibited a direct correlation with the horizontal and vertical distances of the jet plume's terminal rise and return point. As the crossflow velocity increased, the jet plume was propelled down stream. Furthermore, a rise in jet densimetric Froude number led to higher vertical distances for the plume, resulting in a more distant return point. In cases with lower crossflow velocities and densimetric Froude numbers, mixing efficiency was diminished. The study highlights that plume mixing efficiency at both terminal rise and return points is subject to the combined effects of crossflow velocity and densimetric Froude number.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0605-cd

Year: 2023