Numerical resolution of mass, momentum and energy equations in a 3D steady state and transient models. Application to the next generation of HVAC&R components and equipment
This thesis comprises two primary components: firstly, a comprehensive review of advanced computational methods employed in the field of computational fluid dynamics (CFD), and secondly, the development and validation of bespoke CFD and heat transfer (HT) codes through canonical test cases. In the t...
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| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/414250 |
| Acceso en línea: | https://hdl.handle.net/2117/414250 |
| Access Level: | acceso abierto |
| Palabra clave: | Computational fluid dynamics--Fluid dynamics (Space environment) Dinàmica de fluids computacional--Dinàmica de fluids (Medi espacial) Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids |
| Sumario: | This thesis comprises two primary components: firstly, a comprehensive review of advanced computational methods employed in the field of computational fluid dynamics (CFD), and secondly, the development and validation of bespoke CFD and heat transfer (HT) codes through canonical test cases. In the theoretical component, the focus is on spatial symmetry-preserving discretization of the Navier-Stokes equations, examining both staggered and collocated grid arrangements. Special emphasis is placed on collocated arrangements due to their versatility and suitability for complex geometries. The computational expense of Direct Numerical Simulation (DNS) scales with the Reynolds Number as O(Re11/4 ), presenting significant challenges for turbulent flow simulations. To address this, an introduction to spatial filtering is provided, establishing the groundwork for Large-Eddy Simulations (LES). Further attention is dedicated to Eddy-viscosity models, with a novel approach involving the reformulation of these models using appropriate tensor invariants, culminating in a five-dimensional phase-space of invariants. The practical component of this thesis involves the development of a customized CFD/HT code. Utilizing staggered formulations on non-uniform Cartesian grids ensures computational efficiency without compromising precision, thus offering a robust framework for accurate fluid dynamics simulations. Object-oriented programming (OOP) techniques are employed to develop these codes, which are then tested on canonical cases including laminar and turbulent flows such as lid-driven cavities and differentially heated cavities with an aspect ratio of 4. Rigorous validation against academic benchmarks demonstrates the accuracy, reliability, and capability of these codes to effectively capture complex fluid and thermal dynamics within computational frameworks. |
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