Modelagem computacional de escoamentos turbulentos utilizando a metodologia da fronteira imersa dos volumes fantasmas

Abstract

The capability to digitally simulate the physical world has transformed the manner in which science and engineering interact with nature. As one of the most challenging fields of this transformation, Computational Fluid Dynamics (CFD) has established itself as a fundamental pillar, enabling the high- fidelity representation of complex flows. However, within the scope of immersed boundary methods, the faithful representation of intricate interfaces and their efficient geometric processing remain critical challenges for the robustness and viability of current numerical tools. This thesis presents the development, extension, and improvement of the Ghost-Cell Immersed Boundary Method (IB-GCM) integrated into the MFSim computational platform. The work focuses on the solution and validation of flows involving dynamic and thermal effects, as well as fluid-structure interaction (FSI). The methodology was validated through classical cases, such as Poiseuille flow with thermal effects and flow in coaxial ducts, demonstrating sealing capabilities when using zero-thickness boundaries. Flow around a sphere was simulated in both laminar and turbulent regimes, applying Large Eddy Simulation (LES) closure models and utilizing Adaptive Mesh Refinement (AMR) to efficiently capture high gradients in the vicinity and wake of the sphere. In the context of FSI, the vibration of a submerged plate was validated, and the dynamic response of a clamped-clamped beam subjected to cross-flow was analyzed. Finally, a preliminary analysis of an injector applied to industrial-scale projects was performed. The results consolidated in this thesis ratify the IB-GCM method as a robust, accurate, and versatile tool, capable of addressing the complexity of coupled transport phenomena in complex geometries, bridging the gap between high-rigor academic research and the technological demands of modern industry.