  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.
