Panaches horizontaux non-Boussinesq en milieu homog\`ene

TL;DR

This paper develops a theoretical and experimental study of inclined turbulent buoyant jets and plumes in homogeneous or stratified fluids, extending models beyond the Boussinesq approximation to better predict environmental pollutant dispersion.

Contribution

It introduces a comprehensive model valid for both Boussinesq and non-Boussinesq cases and validates it with laboratory experiments using air and helium jets.

Findings

Model accurately predicts flow behavior in non-Boussinesq conditions.

Laboratory results confirm the model's validity across various density ratios.

Limits of the theoretical model's applicability are established.

Abstract

The environmental impact of pollutants and effluents discharged into the atmosphere or the oceans has led researchers to conduct studies related to this issue. Several works have been carried out in this context in order to reduce the effect on the local environment. These types of ejections in nature are modeled as jets in the presence of a density gradient. In this study we treated the problem of inclined round turbulent buoyant jets and plumes ejected in a homogeneous or stratified fluid, at rest or in motion. The prediction of the flow behavior, i.e. the evolution of its variables, is first treated theoretically from a model whose formalism is valid in both the Boussinesq case as well as in the non-Boussinesq general case. Solving the equations governing the plumes is performed numerically using a Runge-Kutta 4th order. To validate the model, laboratory experiments are performed with round jets of air and helium for a wide range of densities. The confrontation theory-experience aims here to fix the limits of validity of the theoretical model. Keywords: Buoyant jet, plume, non-Boussinesq, laser tomography, image processing, perturbation method.