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Universitat Politècnica de Catalunya

1. Torras Ortiz, Santiago. Numerical simulation of sensible and latent thermal energy storage systems.

Degree: Departament de Màquines i Motors Tèrmics, 2016, Universitat Politècnica de Catalunya

The main objective of this thesis is the numerical resolution of heat transfer and fluid flow problems and its application to study the unsteady behaviour of thermal energy storage (TES) systems. Three different systems have been considered, covering a wide range of working conditions (from very low cryogenic temperature to very high temperature CSP plant) and applications (from domestic/residential to renewable or aerospace industry). In that sense, i) for residential heat recovery systems in the low-to-medium temperature range; ii) a thermal accumulator used in a in-space cryogenic propulsion system in the low temperature range and; iii) the two-tank thermal energy storage system in concentrating solar power (CSP) plants in the high temperature range. The thesis is divided into five chapters. Chapter 2 is devoted to present the methodology employed for the resolution of Computational Fluid Dynamics (CFD) and Heat Transfer problems in a drain water heat recovery (DWHR) storage-type unit for residential housing. The study of the performance of this device has been carried out using both numerical and experimental tools. The numerical simulation has been performed using the NEST platform, where the different elements of the DWHR storage are linked to solve the system. The discretisation of the governing equations based on finite volume techniques (FVM) is presented. Numerical techniques such as the discretisation schemes, boundary conditions implementation and solution procedure for incompressible and transient flow problems are shown. Special empirical correlations have been implemented to be used in the numerical resolution of the single-phase flow inside the coiled pipe. An experimental infrastructure has been developed to analyse the whole system. Different internal flow rates and operational temperatures have been studied. The numerical results are compared against experimental results. The numerical simulations performed predict reasonably the transient behaviour of the DWHR storage device. Chapter 3 focuses the attention on a Low Temperature Accumulator prototype used in an in-space cryogenic propulsion system. The numerical simulation has been carried out using the NEST platform, where the different elements of the thermal accumulator are linked to solve the whole system. In this chapter, two numerical models have been adapted, one used to solve the two-phase flow inside ducts working under cryogenic conditions, and another to solve the PCM using a fixed-grid enthalpy model. The numerical analysis is based on: i) a one-dimensional and transient resolution of the governing equations for the fluid flow of propellant; ii) a multi-dimensional and transient resolution of the governing equations in the region occupied by the PCM, incorporating a model for the turbulence to solve the convection phenomena involved; iii) the solid elements are modelled considering a multidimensional and transient treatment of the thermal conduction equation. The numerical results are compared against experimental results from the… Advisors/Committee Members: [email protected] (authoremail), false (authoremailshow), Rigola Serrano, Joaquim (director), Oliet Casasayas, Carles (codirector), Castro González, Jesús (codirector), true (authorsendemail).

Subjects/Keywords: Àrees temàtiques de la UPC::Energies; 004; 536; 621; 69

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APA (6th Edition):

Torras Ortiz, S. (2016). Numerical simulation of sensible and latent thermal energy storage systems. (Thesis). Universitat Politècnica de Catalunya. Retrieved from http://hdl.handle.net/10803/392616

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Torras Ortiz, Santiago. “Numerical simulation of sensible and latent thermal energy storage systems.” 2016. Thesis, Universitat Politècnica de Catalunya. Accessed March 19, 2019. http://hdl.handle.net/10803/392616.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Torras Ortiz, Santiago. “Numerical simulation of sensible and latent thermal energy storage systems.” 2016. Web. 19 Mar 2019.

Vancouver:

Torras Ortiz S. Numerical simulation of sensible and latent thermal energy storage systems. [Internet] [Thesis]. Universitat Politècnica de Catalunya; 2016. [cited 2019 Mar 19]. Available from: http://hdl.handle.net/10803/392616.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Torras Ortiz S. Numerical simulation of sensible and latent thermal energy storage systems. [Thesis]. Universitat Politècnica de Catalunya; 2016. Available from: http://hdl.handle.net/10803/392616

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Universitat Rovira i Virgili

2. Ordoñez García, Arturo. Effects of architectural design variables on energy and environmental performance of office buildings.

Degree: Departament d'Enginyeria Mecànica, 2016, Universitat Rovira i Virgili

This thesis addresses the understanding of the effects that main architectural design variables have on energy, environmental and economic performance of office buildings, exploring some of the analytical methods that offer greater potential nowadays. It is aimed to contribute to the development of approaches, methods and tools that facilitate the decision-making during the architectural design processes, especially in the early stages. It is also aimed to generate information that helps to improve the criteria applied in the development of building energy codes and sustainability certifications. The research consisted of four major parts: • Development of a parametric project based on the programs EnergyPlus and jEPlus software. • Implementation of Optimization analysis by means of evolutionary algorithms. The analysis is performed with the program jEPlus+EA. • Application of two sensitivity analysis methods, Morris and Sobol, in order to investigate the relative importance of each architectural design variable. • Implementation of artificial neural networks to create meta-models that are able to predict, with reasonable accuracy, the energy, environmental and economic performance of buildings Advisors/Committee Members: [email protected] (authoremail), false (authoremailshow), Coronas Salcedo, Alberto (director), Zhang, Yi (director), true (authorsendemail).

Subjects/Keywords: Edificis energia; Acompliment; Optimització; Edificios Energia; Desempeño; Optimización; Buildings energy; Performance; Optimization; Enginyeria i Arquitectura; 621; 69; 72

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ordoñez García, A. (2016). Effects of architectural design variables on energy and environmental performance of office buildings. (Thesis). Universitat Rovira i Virgili. Retrieved from http://hdl.handle.net/10803/395212

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Ordoñez García, Arturo. “Effects of architectural design variables on energy and environmental performance of office buildings.” 2016. Thesis, Universitat Rovira i Virgili. Accessed March 19, 2019. http://hdl.handle.net/10803/395212.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Ordoñez García, Arturo. “Effects of architectural design variables on energy and environmental performance of office buildings.” 2016. Web. 19 Mar 2019.

Vancouver:

Ordoñez García A. Effects of architectural design variables on energy and environmental performance of office buildings. [Internet] [Thesis]. Universitat Rovira i Virgili; 2016. [cited 2019 Mar 19]. Available from: http://hdl.handle.net/10803/395212.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ordoñez García A. Effects of architectural design variables on energy and environmental performance of office buildings. [Thesis]. Universitat Rovira i Virgili; 2016. Available from: http://hdl.handle.net/10803/395212

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Universitat Politècnica de Catalunya

3. Valdés Vázquez, Jesús Gerardo. Nonlinear Analysis of Orthotropic Membrane and Shell Structures Including Fluid-Structure Interaction.

Degree: Departament de Resistència de Materials i Estructures a l'Enginyeria, 2007, Universitat Politècnica de Catalunya

Nowadays, fluid-structure interaction problems are a great challenge of different fields in engineering and applied sciences. In civil engineering applications, wind flow and structural motion may lead to aeroelastic instabilities on constructions such as long-span bridges, high-rise buildings and light-weight roof structures. On the other hand, biomechanical applications are interested in the study of hemodynamics, i.e. blood flow through large arteries, where large structural membrane deformations interact with incompressible fluids. In the structural part of this work, a new methodology for the analysis of geometrically nonlinear orthotropic membrane and rotation-free shell elements is developed based on the principal fiber orientation of the material. A direct consequence of the fiber orientation strategy is the possibility to analyze initially out-ofplane prestressed membrane and shell structures. Additionally, since conventional membrane theory allows compression stresses, a wrinkling algorithm based on modifying the constitutive equation is presented. The structure is modeled with finite elements emerging from the governing equations of elastodynamics. The fluid portion of this work is governed by the incompressible Navier-Stokes equations, which are modeled by stabilized equal-order interpolation finite elements. Since the monolithic solution for these equations has the disadvantage that take great computer effort to solve large algebraic system of equations, the fractional step methodology is used to take advantage of the computational efficiency given by the uncoupling of the pressure from the velocity field. In addition, the generalized-α time integration scheme for fluids is adapted to be used with the fractional step technique. The fluid-structure interaction problem is formulated as a three-field system: the structure, the fluid and the moving fluid mesh solver. Motion of the fluid domain is accounted for with the arbitrary Lagrangian-Eulerian formulation with two different mesh update strategies. The coupling between the fluid and the structure is performed with the strong coupling block Gauss-Seidel partitioned technique. Since the fluid-structure interaction problem is highly nonlinear, a relaxation technique based on Aitken's method is implemented in the strong coupling formulation to accelerate the convergence. Finally several example problems are presented in each field to verify the robustness and efficiency of the overall algorithm, many of them validated with reference solutions. Advisors/Committee Members: [email protected] (authoremail), false (authoremailshow), Miquel Canet, Juan (director), Oñate, E. (Eugenio) (director).

Subjects/Keywords: fiber orientation wrinkling; prestressed; fluid-structure interaction orthotropic; incompressibles fluids; rotation-free shells; membranes; finite elements; fractional step; 1206, 3305, 2204, 3301; 621; 624; 69

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Valdés Vázquez, J. G. (2007). Nonlinear Analysis of Orthotropic Membrane and Shell Structures Including Fluid-Structure Interaction. (Thesis). Universitat Politècnica de Catalunya. Retrieved from http://hdl.handle.net/10803/6866

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Valdés Vázquez, Jesús Gerardo. “Nonlinear Analysis of Orthotropic Membrane and Shell Structures Including Fluid-Structure Interaction.” 2007. Thesis, Universitat Politècnica de Catalunya. Accessed March 19, 2019. http://hdl.handle.net/10803/6866.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Valdés Vázquez, Jesús Gerardo. “Nonlinear Analysis of Orthotropic Membrane and Shell Structures Including Fluid-Structure Interaction.” 2007. Web. 19 Mar 2019.

Vancouver:

Valdés Vázquez JG. Nonlinear Analysis of Orthotropic Membrane and Shell Structures Including Fluid-Structure Interaction. [Internet] [Thesis]. Universitat Politècnica de Catalunya; 2007. [cited 2019 Mar 19]. Available from: http://hdl.handle.net/10803/6866.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Valdés Vázquez JG. Nonlinear Analysis of Orthotropic Membrane and Shell Structures Including Fluid-Structure Interaction. [Thesis]. Universitat Politècnica de Catalunya; 2007. Available from: http://hdl.handle.net/10803/6866

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.