Simulação de grandes escalas de escoamentos turbulentos incompressíveis e compressíveis na presença de paredes

Author(s)

Luiz Augusto Camargo Aranha Schiavo

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Mecânica
• Defense date: 2019-02-21

Examining board members

William Roberto Wolf; Britton Jeffrey Olson; Marcello Augusto Faraco de Medeiros; Márcio Teixeira de Mendonça

• Advisor: William Roberto Wolf; João Luiz Filgueiras de Azevedo

Abstract

The development of turbulent flows in the presence of walls occurs in both industrial and nature applications. This class of turbulent flows has great differences when compared to free turbulence and the advances in experimental techniques and computational power allow a deeper understanding of the turbulent structures found in such flows. In this work, we study incompressible and compressible turbulent flows in channels using the large eddy simulation technique. Incompressible flows in channels with shape modifications are studied in order to understand the effects of pressure gradient variations and curvature in the formation of streak instabilities. In addition, the effects of shape variation on flow anisotropy are also investigated through an analysis of the anisotropic Reynolds stress tensor invariants and the turbulent kinetic energy spectral balance. Supersonic flows over smooth channels are also analyzed in order to understand the effects of compressibility and Reynolds number on turbulence and the importance of the hydrodynamic, thermal and acoustic modes in the coherent turbulent structures. This analysis is performed through an assessment of the advection velocities of the velocity components and thermodynamic properties in different regions of the boundary layer. Finally, flow modal decomposition techniques are applied to investigate the physics of coherent structures in supersonic wall-bounded flows for different Mach and Reynolds numbers (AU)

• FAPESP's process: 14/07623-6 - Numerical study of the effect of a geometric disturbance in turbulent flows
• Grantee: Luiz Augusto Camargo Aranha Schiavo
• Support type: Scholarships in Brazil - Doctorate