Computational simulation of round thermal jets in an ambient cross flow using a large-scale hydrodynamic model

Abstract

This paper presents the numerical simulation of single, circular, turbulent, thermal jets discharged into an ambient fluid body with a uniform cross flow. The study utilizes a 3D hydrodynamic model to predict the dynamics of the evolving jets, with the model simulations calibrated against benchmark laboratory experimental datasets. Within the numerical-experimental model comparisons, the mean centreline temperature and velocity fields of the evolving jets are investigated in order to understand and predict the jet diffusion characteristics within the flowing ambient fluid body. Direct comparison between the numerical model predictions and laboratory datasets reveals that, with appropriate parameterization of the mixing processes and the selection of an appropriate numerical grid resolution, the large-scale hydrodynamic model can simulate both the near- and far-field thermal jet behaviour with good overall agreement, thus revealing a valid modelling tool used by environmental regulators for assessing the conformity of water quality of marine wastewater discharges.

Keywords:

• Dispersion processes and models
• laboratory studies
• numerical simulations
• RANS models
• turbulent jets
• velocity and temperature measurements

Acknowledgements

The authors would like to thank Andrea Pedroncini, DHI Italy, for the technical advice provided by during the numerical modelling phase of the study. The insightful comments of two anonymous reviewers and the Associate Editor are also acknowledged as leading to significant improvements to the paper.