DSpace Collection:http://repositorio.ugto.mx/handle/20.500.12059/42122024-03-28T22:41:02Z2024-03-28T22:41:02ZEvaluation of microchannel networks for efficient cooling of IC chips using Single-Phase coolingCARLOS ALBERTO RUBIO JIMENEZhttp://repositorio.ugto.mx/handle/20.500.12059/80272023-03-30T16:54:50Z2012-08-01T00:00:00ZTitle: Evaluation of microchannel networks for efficient cooling of IC chips using Single-Phase cooling
Authors: CARLOS ALBERTO RUBIO JIMENEZ
Contributor: Satish Kandlikar
Abstract: This era is called information age. Computational equipment make possible to generate, transfer and process data each second worldwide. IC chips are the bases of these electronic devices. Thus, there is a deep interest in these high-tech electronic technologies. Since the development of the transistor in the Bell Laboratories, the IC chips have grown strongly, mainly in the slenderness and its number of transistors. For example, the Intel? Core” ¡7 is currently a part of the newest computational processor generation manufactured by Intel” Corporations. lts architecture is formed by 774 million of 64 nm-transistor (compared on its predecessor, this device has an increase of fourteen times the number of these vital components.) By 2016, it is projected that the next computation processor generation will have 10-30 nm architecture with an increase of 1.3 times in the number of transistors. Although the panorama looks pretty good, there is an important drawback of this tendency. The transfer of electrons into the IC chip generates an important amount of thermal energy, which is affected directly by the increase of the number of transistors, and inversely by the decrease of the computational processor size. Thus, several researchers have been focused to enhance current cooling IC chip technology as well as generate novel cooling systems.
Since the beginning of this century, liquid cooling technologies have received a deep attention for the next cooling electronic device generation. Large part of the researchers developed in this area has been addressed to study microchannel heat sinks, The large heat transfer coefficient that the cooling fluid can achieve when is flowing through these tiny devices as well as the heat sink slenderness, make them a true alternative for dissipating the high heat fluxes to be generated in the
next computational processors generation. Good knowledge of the phenomena and generation of novel configurations have been the main result of these studies. However, a couple of problem remains present: non-uniform junction temperature and high fluid pressure drop. Studies focused to analyze the thermo-mechanical effects generated on the IC chip have shown that the hotspots produce several damages into the chip. Thus, it is highly desirable to generate homogeneous temperature in the cooling system. Moreover, the system energy requirements increase directly with the pressure drop. Thus, reduction of this energy losses is desirable in order to do more reliable the cooling system (appropriate pumping power).
This work is a contribution in the microchannel heat sink area aimed to obtain a micro cooling system capable to generate uniform junction temperature with the lowest pressure drop penalty. Analytical and numerical studies are carried out in order to achieve this goal / Carlos Alberto Rubio-Jimenez ; directores: Satish G. Kandlikar, Abel Hernandez-Guerrero.2012-08-01T00:00:00ZAnalytical and Numerical Study of The Plate Twist Test in Composite Laminates and Sandwich PanelsRENNY JESUS GUILLEN RUJANOhttp://repositorio.ugto.mx/handle/20.500.12059/46212021-04-21T17:28:37Z2020-05-01T00:00:00ZTitle: Analytical and Numerical Study of The Plate Twist Test in Composite Laminates and Sandwich Panels
Authors: RENNY JESUS GUILLEN RUJANO
Contributor: ADRIAN HERNANDEZ PEREZ
Abstract: An analytical and numerical research work related to the plate twist test of specially orthotropic plates is developed in this thesis. Two finite element models and two analytical closed-form solutions are developed for deflections and rotations of thick specially orthotropic materials under twisting loads by using the first-order shear deformation theory. These solutions show good agreement in the compliance predictions with respect to previously reported measurements and finite element estimations. The first solution considers the effect solely of the stiffness D66 and A44, A55 in the compliance, assuming shear correction factors of 2/3 and a twisting moment Mxy = P/4 The second solution not only considers the influence of D66 and A44, A55 on the compliance but alsothat by D11, D12, D22 stiffnesses, varying the shear correction factors and Mxy according to the material system and geometry. The results of the parametrical analys is show that both solutions are able to adequately predict the deflections of specially orthotropic plates from low to moderately high side-length to thickness ratios (1 ≤ side-lengths/thickness ≤ 20and(1 ≤ side-lengths/thickness ≤ 61), respectively; also both solutions can be used for rectangular plates with ratios between sides-length (1 ≤side-length in X axis/side-length in Y axis ≤ 10).Examination of the in-plane shear modulus ratio between face sheets and core (G12f / G12c) points out that the first solutions lightly underpredicts the compliance with respect to finite element method (FEM), specially for G12f / G12c ratios larger than 100,whilstthe second solution match very well for those ratios. Examination of the Mxy by finite element method showed that Mxy has a parabolic behavior for sandwich panels with compliant cores, reaching a maximum value at the center of the plate different to P/4 and being dependent of the material properties.2020-05-01T00:00:00ZExperimental and Numerical Study of Molten Carbonate Fuel Cells Working in Reversible ModeJUAN PEDRO PEREZ TRUJILLOhttp://repositorio.ugto.mx/handle/20.500.12059/46202021-04-21T17:18:50Z2019-09-01T00:00:00ZTitle: Experimental and Numerical Study of Molten Carbonate Fuel Cells Working in Reversible Mode
Authors: JUAN PEDRO PEREZ TRUJILLO
Contributor: FRANCISCO ELIZALDE BLANCAS
Abstract: Molten Carbonate Fuel Cells (MCFCs) have a great potential to help facing the global warming problem. MCFCs have the characteristics that can be used as a fuel cell to produce electricity, can be used as a carbon capture and sequestration device helping to manage the carbon dioxide emissions, as well as an electrolyzer to produce hydrogen or synthesis gas using carbon dioxide and water as fuels. The scope of this thesis is to test experimentally and predict numerically the performance of a single MCFC in reversible mode, i.e., the cell operates switching between fuel cell mode (MCFC) and electrolysis mode (Molten Carbonate Electrolysis Cell, MCEC) in order to obtain more knowledge for the conditions that increase the electrical power or hydrogen production, respectively. Therefore, three experimental campaigns were carried out in order to study the performance of a single cell operating: 1) in fuel cell mode, 2) in reversible mode, and 3) in electrolysis mode through a long-term test. The single cell tested has an electrode-electrolyte interface area of 80 cm2. The aim of the first experimental campaign was to collect experimental data of the cell operating as MCFC which help to compare the cell performance with five different zero-dimensional models. Then, one model was selected in order to fit with the experimental data in fuel cell mode. During the second experimental campaign different operative parameters were tested in reversible mode to collect data in both operative modes. The fitted model was then compared in electrolysis mode with the experimental data acquired on the cell running in reversible mode. The program code was written in Anaconda Python 3.7. Finally, in the third experimental campaign, the cell was tested in electrolysis mode for almost 1000 h with the aim of studying the potential to operate the single cell as an electrolyzer.2019-09-01T00:00:00ZAnálisis Termodinámico del Sistema de Llenado de Hidrógeno en Recipientes de Presión CriogénicosJUAN GREGORIO HORTELANO CAPETILLOhttp://repositorio.ugto.mx/handle/20.500.12059/46182021-05-14T17:46:20Z2017-06-01T00:00:00ZTitle: Análisis Termodinámico del Sistema de Llenado de Hidrógeno en Recipientes de Presión Criogénicos
Authors: JUAN GREGORIO HORTELANO CAPETILLO
Contributor: ARMANDO GALLEGOS MUÑOZ
Abstract: El objetivo de este trabajo es realizar un análisis termodinámico del sistema de llenado de hidrógeno líquido en recipientes de presión criogénicos propuesto por el Laboratorio Nacional de Lawrence Livermore en Estados Unidos (USA). Es importante analizar los cambios de energía del hidrógeno líquido en el sistema de la tubería que conecta la bomba con el tanque criogénico dentro del automóvil producidos por la diferencia de temperaturas entre el ambiente y el hidrógeno líquido y las caídas de presión implementando un aislante de espuma de poliuretano. En la bomba de hidrógeno líquido es demostrar que no opera a entropía constante como lo especifica el fabricante y que genera cambios de energía en el sistema de llenado lo cual hace que el tanque criogénico reciba menor masa de hidrógeno a la misma presión final de llenado. Los resultados teóricos que se van a obtener en la tubería son: caídas de presión, la transferencia de calor hacia los alrededores y el tiempo en que la tubería se estabiliza cuando se encuentra a temperatura ambiente. Y los resultados teóricos en el tanque criogénico obtenidos son: masa, temperatura, presión y densidad finales cuando el tanque es llenado; posteriormente éstos resultados serán validados con datos experimentales.2017-06-01T00:00:00Z