Impact Of The Initial Streamwise Inclination Of A Double Jet Emitted Within A Cool Crossflow On Its Temperature Field And Pollutants Dispersion

摘要

An experimental study and a numerical modeling are carried out simultaneously on a twin inclined jets' configuration issuing into a cooler crossflow. The main purpose of this study is to track the overall evolution of the jets among the surrounding flow and then determine the thermal and mass transfer features that characterize the resulting flowfield. The experimental data are depicted by means of a particle image velocimetry technique; whereas the numerical three-dimensional model is simulated through the resolution of the different governing Navier-Stokes' equations by means of the finite volume method. Two different closure models were tested: the standard k-ε model and the Reynolds stress model (RSM) second order model. The introduction of the latter in such a configuration brings some valuable improvement since it allows the detection of the slightest "variations within the domain and then describes the least occurring mechanisms. The confrontation of the differently processed numerical results with the experimentally tracked data comforted our opinion since it proved the better efficiency of the RSM model for the description of the handled flow; that's why we adopted it for the rest of the paper. Once the validation obtained, we proceeded to the evaluation of the influence of the initial streamwise inclination of the emitted jets on thernengendered thermal field and on the pollutants' dispersion. For the matter, we tested the following angles: 30°, 45°, 60° and 90°. After that, we represented the temperature variation along different directions in order to detail its behavior in all of them and at different levels. This characterization is highly recommended since it may promote the efficiency of several applications (mainly the cooling applications). We also evaluated the influence of this same parameter; the initial inclination; on the pollutants' dispersion due to the high and alarming importance of the problem on the environment. All these considerations allowed us then to well characterize the impact of the injection inclination on the mixing process of the tandem emitted jets through the cooler oncoming crossflow as well as on the pollutants' dispersion and mixing within the whole domain.