Soluções contı́nuas e discretas de escoamentos cisalhantes livres em regimes laminar e turbulento.

Abstract

This master dissertation presents the detailed development for continuous solutions of the simplified physical models of free shear flows in laminar and turbulent regimes, and their comparison with discrete solutions or discrete data. The method used to obtain the solutions is the self-similarity method, which makes the results valid only in regions of the flow where the profiles of the properties in question are self-similar. For turbulent flow solutions, two forms of the Prandtl mixing-length model, the original form and a simplified form called Prandtl- Reichardt model, were used. After obtaining the continuous solutions for various properties of the free shear flows, such as mean velocities and spreading rate , the continuous profiles were compared with discrete data obtained from material experiments or from computational experiments. The material experiments were available in the literature, and the computational experiments were performed as part of the present work. For the accomplishment of the computational experiments, it was used the code MFSim, developed in the Laboratory of Fluid Mechanics (MFLab) of the Federal University of Uberlandia (UFU). Two turbulence closure models, with two transport equations of the k − epsilon class, were implemented in the code. The present work presents continuous solutions and comparisons between the continuous and discrete profiles for temporal mixing layers, plane jets and wakes generated by immersed bodies, evaluated in distant regions of the body, all in laminar and turbulent regimes and for spatial mixing layers only in the turbulent regime.