Simulação de grandes escalas de jatos periódicos temporais utilizando a metodologia psedo-espectral de Fourier

Abstract

The turbulence in fluids is one of the most challenging problems in actuality, especially in industrial applications, like mixtures processes, heat transfer, lubrication, combustion, or propulsion systems in airplanes In front of such interest, in the present work, the objective is the analysis of the transition of turbulence of temporal jets at moderate Reynolds numbers using the LES (Large Eddy Simulation) methodology. A high order resolution computational code, based on Fourier pseudo-spectral method, called ESPC3D, was developed in the present work for simulating the development of temporal jets in transition and/or turbulent state. Such code was developed in the Laboratory of Heat and Mass Transfer and Fluid Dynamics (LTCM) of Federal University of Uberlândia. Consistent results were obtained from the point of view of physical analysis, using the developed code. The simulations performed allowed to verify the transition to turbulence as well as the coherent structures that characterizes it. In addition, the influence of the LES methodology and the Reynolds number influence in such flows could be verified. The proximity of the inertial region to the inclination of -5/3, from Kolmogorov Theory, and the decay region were verified in the energy spectra.