Simulation of the Onset turbulent flow around a Isothermal Complex Geometries: an analysis of thermofluid dynamic flow

Resumo

In this work, in the area of Computational Fluid Dynamics (CFD), more specifically in the area of thermofluid dynamics for two-dimensional flows (2D), and also considering, the fluid-body interaction, allied to the phenomena of heat-transfer by mixed convection and the beginning of processes of the turbulent flow phenomenon in the fluid-body interaction, a study is proposed that demonstrates the efficiency in the analysis and simulation of these complex phenomena. We adopt an Eulerian approach for a fixed mesh, which is intended to represent the thermofluid dynamic movement, working together with a Lagrangian mesh, the latter being intended to discretize the immersed body. The strategy, in this work, allows approaching complex isothermal geometries, which present a certain aerodynamic degree on their surface, being popularly known as blunt body, where this, in turn, is immersed in an incompressible Newtonian fluid. One of the contributions of this work is the introduction of a simple but efficient method to calculate the Nusselt number. Regarding the process of validation and modeling of the physical phenomena of interest, that is, regarding the effectiveness of the methodology, called the Immersed Frontier, an implementation with low computational cost was carried out for the transfer of mixed convection heat, as well as for modeling the turbulence, namely, making use of the Spalart-Allmaras model, in the context of the URANS (Unsteady Reynolds Average Navier -Stokes) methodology. Numerical results showed good convergence with data available in the literature, which confirms the numerical precision and reliability of the adopted model.