Advanced study for the computational resolution of conservation equations of mass, momentum and energy
This Final Master’s Thesis presents a comprehensive study on the computational resolution of the NavierStokes equations for incompressible and Newtonian flows in the turbulent regime utilizing the Finite Volume Method by using user-implemented C++ codes. The project is divided into several chapters,...
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| Formato: | tesis de maestría |
| Fecha de publicación: | 2024 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/414737 |
| Acesso em linha: | https://hdl.handle.net/2117/414737 |
| Access Level: | acceso abierto |
| Palavra-chave: | Navier-Stokes equations Finite element method Computational fluid dynamics CFD C++ (Computer program language) Turbulence Large eddy simulation Equacions de Navier-Stokes Elements finits, Mètode dels Dinàmica de fluids computacional Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids |
| Resumo: | This Final Master’s Thesis presents a comprehensive study on the computational resolution of the NavierStokes equations for incompressible and Newtonian flows in the turbulent regime utilizing the Finite Volume Method by using user-implemented C++ codes. The project is divided into several chapters, each of them addressing distinct aspects of the project. The initial chapter outlines the project objectives, scope, requirements and the state of the art in the numerical fluid simulations. An introduction to the numerical techniques used to transform the differential equations modeling the flow behavior into a discrete set of algebraic equations follows. Subsequently, a theoretical study of the turbulence phenomenon, as well as the diverse manners of computationally model it are detailed. To finalize the theoretical framework, the numerical methods used for discretizing the governing equations are covered. The numerical simulations follow. The core of the thesis involves the adaptation of the developed code to solve the Turbulent Channel Flow benchmark case. Initial verification cases are performed at laminar friction Reynolds numbers, with simulations yielding accurate results when compared with analytical solutions. The study progresses to turbulent simulations at friction Reynolds numbers of 180 and 395. Once again, validation against reference literature shows relatively accurate results. However, larger deviations are observed at higher friction Reynolds numbers due to the increased number of flow scales. The introduction of LES turbulence models does not significantly enhance the results, with modeled ones only outperforming non-modeled simulations in specific variables. The numerical simulation of the Taylor-Green Vortex case follows. Simulation results, both with and without turbulence modeling, are presented and analyzed. Similarly, accurate results are obtained when compared to benchmark cases. However, once again, the turbulence-modeled ones do not outperform the non-modeled ones. Lastly, an energetic study of the Navier-Stokes equations is conducted. The last simulation case is the turbulent natural convection flow inside a rectangular cavity, namely Turbulent Differentially Heated Cavity. Simulations in both laminar and turbulent regimes are conducted, with results compared to the reference literature. At all the studied Rayleigh numbers, significant agreement with reference literature is obtained. Then, the environmental impact of the project is assessed, quantifying the CO2 emissions and nuclear waste produced during the thesis development. The study concludes that the environmental footprint is negligible compared to other engineering projects, while the solution proposed by the project is beneficial for the environment. The total budget for the study, including human and material resources follows. Finally, the general conclusions drawn during the development of the thesis are provided, as well as diverse suggestions to further improve the study. |
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