Estudio del comportamiento térmico del disipador de calor de un extrusor de impresora 3D

A lo largo de los años las tecnologías de fabricación aditiva por impresión 3D han evolucionado rápidamente hasta a actualidad. Su aplicación predominante es la fabricación de prototipos o series muy cortas de piezas. Además, con el movimiento Open-Source y el alto grado de accesibilidad de procesos de fabricación por impresión 3D como el modelado por deposición de filamento fundido han llevado a este tipo de tecnología hasta aplicaciones domésticas a través de máquina a pequeña escala. En este trabajo de final de grado se estudia el comportamiento térmico de una de las piezas clave para la vida útil de estas máquinas: el disipador de calor. Las impresoras 3D llegan a alcanzar altas temperaturas de hasta 250ºC que, en caso de no ser correctamente regulada, pueden provocar graves problemas al conjunto de la máquina reduciendo su vida útil y funcionalidad. Para ello, se han realizado análisis computacionales de tres modelos geométricos diferentes de disipador para encontrar el más óptimo: el que consiga disipar mayor cantidad de calor, para diferentes flujos de aire refrigerante proveniente de un ventilador del que están dotadas las impresoras 3D. Además, se han realizado pruebas experimentales para validar los resultados computacionales, combinando finalmente los resultados de ambas fases de análisis

A comparative study of the thermal behavior of three different 3D printer liquefiers

The expansion of 3D printing systems as mechatronic devices able to localize manufacturing activities has attracted the attention in academic and professional labs worldwide. However, little is known from a formal point of view about the actual possibilities of optimization in terms of hardware and software. This paper proposes alternative geometrical designs of RepRap 3D printer liquefiers, and offers an evaluation of their thermal performance by analyzing the temperature profiles derived from their functioning in a steady state regime. For that purpose, finite element calculation and experimental techniques are combined and compared. A detachable model of liquefier, used in numerous RepRap 3D printers, has been taken as a reference to design and manufacture two new variations. As the objective of the liquefier is to heat the plastic material while limiting the temperature at its top, heat conduction must be prevented by means of a refrigerating fan faced at the liquefier body. The effect of that fan has been introduced in the system of study, by evaluating the influence of five different fan velocities on the final temperature profile. All combinations of fan speed and liquefier geometry have been calculated through a finite elements model. Then, they have been reproduced experimentally, measuring discrete temperatures at different heights of the liquefier by a group of thermocouples installed on the surface of the fins composing the liquefier heat sink. Results showed that the defined FEM model reproduces acceptably the final temperature profiles obtained by experimental measures. Furthermore, the new proposed design provided with thick fins shows its good performance when the 3D printing process is performed with a fan speed higher than 10% (defined according to a PWM function programmed at the 3D printer's firmware), while its design presents a much lower manufacturing time with regards to the present available design. It is also concluded that refrigerating the liquefier during a standard 3D printing process with an airflow higher than PWM¿=¿20% is not recommended, due to a fall in efficiency and not remarkable refrigerating effect obtained through it.Postprint (author's final draft

Enhancing surface topology of Udimet®720 superalloy through ultrasonic vibration-assisted ball burnishing

This contribution reports the effects of an ultrasonic-vibration assisted ball burnishing process on the topological descriptors of nickel-based alloy Udimet®720. This material is of high interest for the transportation industry, and specifically for the aeronautical sector. Despite the acknowledged necessity to finish this material to achieve excelling mechanical performances of parts, surface integrity enhancement by means of plastic deformation through ball burnishing has seldom been explored in previous references so far. In this paper, different surface descriptors are used to report how the topology changes after ultrasonic-assisted ball burnishing, and how burnishing conditions influence that change. The burnishing preload and the number of passes are the only influential factors on surface change, whereas the feed velocity of the tool and the strategy reveal not to be relevant on the result. Additionally, the extent to which the process successfully modifies the objective surfaces is highly divergent depending on the original scale of the treated surface. The assistance of the process with vibrations also shows that the resulting topologies are characterized by a periodical pattern of repetitive peaks and valleys that are extended on the surface with a higher frequency in comparison to the non-assisted process, which could influence in the functional deployment of workpieces treated through it, and could deliver an advantage with regard to its non-assisted homologous process.Peer ReviewedPostprint (published version

The value of meta-data for water resource recovery facilities

[EN] Meta-data refers to descriptive information essential to convert large volumes of raw data into useful resources. With the advance of digitalisation in the water sector, it is fundamental to avoid data graveyards and, on the other hand, using collected data to address current and future problems. This white paper focuses on the crucial role that meta-data has in responding to future and possibly unpredictable challenges. The aim of this document is to present the `meta-data challenge¿ and to highlight the need to consider meta-data when collecting information as part of good digitalisation practices.Aguado García, D.; Blumensaat, F.; Baeza, JA.; Villez, K.; Ruano, MV.; Samuelsson, O.; Plana, Q. (2021). The value of meta-data for water resource recovery facilities. H2Open Journal. 1-15. http://hdl.handle.net/10251/188561S11

Mutations in TRIM63 cause an autosomal-recessive form of hypertrophic cardiomyopathy

Objective: Up to 50% of patients with hypertrophic cardiomyopathy (HCM) show no disease-causing variants in genetic studies. TRIM63 has been suggested as a candidate gene for the development of cardiomyopathies, although evidence for a causative role in HCM is limited. We sought to investigate the relationship between rare variants in TRIM63 and the development of HCM. Methods: TRIM63 was sequenced by next generation sequencing in 4867 index cases with a clinical diagnosis of HCM and in 3628 probands with other cardiomyopathies. Additionally, 3136 index cases with familial cardiovascular diseases other than cardiomyopathy (mainly channelopathies and aortic diseases) were used as controls. Results: Sixteen index cases with rare homozygous or compound heterozygous variants in TRIM63 (15 HCM and one restrictive cardiomyopathy) were included. No homozygous or compound heterozygous were identified in the control population. Familial evaluation showed that only homozygous and compound heterozygous had signs of disease, whereas all heterozygous family members were healthy. The mean age at diagnosis was 35 years (range 15-69). Fifty per cent of patients had concentric left ventricular hypertrophy (LVH) and 45% were asymptomatic at the moment of the first examination. Significant degrees of late gadolinium enhancement were detected in 80% of affected individuals, and 20% of patients had left ventricular (LV) systolic dysfunction. Fifty per cent had non-sustained ventricular tachycardia. Twenty per cent of patients suffered an adverse cerebrovascular event (20%). Conclusion: TRIM63 appears to be an uncommon cause of HCM inherited in an autosomal-recessive manner and associated with concentric LVH and a high rate of LV dysfunction

Medidas para reducir la exposición de los ciclistas a los principales contaminantes atmosféricos urbanos

Recoge los principales resultados generados durante la realización del proyecto LIFE+RESPIRA, llevado a cabo en la ciudad de Pamplona (Navarra, España) por un equipo interdisciplinar constituido por más de 30 investigadores pertenecientes a la Universidad de Navarra, el Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) y Gestión Ambiental de Navarra (GAN-NIK). El libro, que se ha publicado en castellano y en inglés, se ha dividido en 7 capítulos: 1. ¿Ciudades sostenibles? 2. Exposición de los ciudadanos a la contaminación atmosférica 3. Papel de la vegetación urbana en la calidad del aire 4. Modelos de alta resolución para evaluar la calidad del aire 5. Impactos de la contaminación urbana 6. Movilidad y sostenibilidad urbanas 7. Comunicación y educación ambiental. Este libro pretende ser una guía de utilidad para científicos, gestores y ciudadanos, aportando un conjunto de herramientas que permitan mejorar la calidad de vida de nuestras ciudades. Además, quiere rendir un homenaje a todos los voluntarios ciclistas que han participado en dicho proyecto y que son los verdaderos artífices del mismo, ya que gracias a su dedicación incondicional durante más de dos años, han proporcionado una cantidad ingente de datos sobre la calidad del aire de la ciudad de Pamplona

Reduction of exposure of cyclists to urban air pollution

This book collects the main outcomes that were generated during the implementation of the LIFE+RESPIRA project (LIFE13 ENV/ES/000417), carried out in the city of Pamplona, Navarra, Spain. The research was conducted by a cross-functional team made up of more than 30 researchers belonging to three entities: The University of Navarra, the Centre for Energy, Environmental and Technological Research (CIEMAT) and Environmental Management of Navarra (GAN-NIK)

Vibration assisted ball burnishing for 720 nickel alloy

En aquest treball de final de màster s’analitza l’efecte del procés de brunyit amb bola assistit per vibracions sobre la textura d’una superfície plana prèviament fresada de l’aliatge 720 base níquel. Es tracta d’un material de gran rellevància en el desenvolupament de peces clau a la industria aeronàutica. L’anàlisi es centra en la possible influència de diversos factors del procés com: la força de precàrrega, el número de passades realitzades, la velocitat lineal de l’eina, la topologia de la superfície inicial i l’estratègia seguida per a combinar l’ordre i direcció de les diferents passades. Per a poder estudiar l’efecte de tots aquests factors, s’aplica un disseny d’experiments optimitzat per a minimitzar el número d’assajos necessaris. L’adquisició de dades experimentals es realitza mitjançant un sensor òptic topogràfic y es tracten posteriorment amb un software especialitzat que calcula els diversos paràmetres que caracteritzen la superfície. La discussió dels resultats, que conté diversos estudis estadístics ANOVA, es centra en l’efecte el brunyit sobre: la reducció de la textura, la redistribució del material i la possible reorientació de de l’anisotropia superficial. A més, es comparen els resultats quan el brunyit es realitza amb i sense l’assistència de vibracions. Finalment, es conclou la combinació de factors que resulta en una millor topografia superficial i s’estableixen els següents passos recomanats per a aquesta línia d’investigació.En este trabajo de final de máster se analiza el efecto del proceso de bruñido con bola asistido por vibraciones sobre la textura de una superficie plana previamente fresada de la aleación 720 base níquel. Se trata de un material de gran importancia en el desarrollo de piezas clave de la industria aeronáutica. El análisis se centra en la posible influencia de diversos factores del proceso como: la fuerza de la precarga, el número de pasadas realizadas, la velocidad lineal de la herramienta, la topología de la superficie inicial y la estrategia seguida para combinar el orden y dirección de las distintas pasadas. Para poder estudiar el efecto de todos estos factores, se aplica un diseño de experimentos optimizado para minimizar el número de ensayos necesarios. La adquisición de datos experimentales se realiza mediante un sensor óptico topográfico y se tratan posteriormente con un software especializado que calcula los diversos parámetros que caracterizan a la superficie. La discusión de los resultados, la cual engloba diversos estudios estadísticos mediante ANOVA, se centra en el efecto que tiene el bruñido sobre: la reducción de la textura, la redistribución del material y la posible reorientación de la anisotropía de la superficie. Además, se comparan los resultados cuando el bruñido se realiza con y sin la asistencia de vibraciones. Finalmente, se concluye con la combinación de factores que lleva a una mejor topografía superficial y se establecen los siguientes pasos recomendados para esta línea de investigación.In this master final thesis, the effect of the vibration-assisted ball burnishing process on the texture of a previously milled flat surface of 720 nickel alloy is analysed. It is a material of great importance in the development of key parts in the aeronautical industry. The analysis focuses on the possible influence that five factors of the process may have: the preload force, the number of passes, the linear speed of the tool, the topology of the initial surface and the strategy followed to combine the order and direction of the different passes. In order to study the effect of all these factors, an optimised design of experiments is applied to minimize the number of tests required. The acquisition of experimental data is carried out using a topographic optical sensor and are subsequently treated with specialised software that calculates the parameters that characterise the surface. The discussion of the results, which includes various statistical studies using ANOVA, focuses on the effect of burnishing on the reduction of the texture, the redistribution of the material and the possible reorientation of surface anisotropy. In addition, the results are compared when burnishing is performed with and without the assistance of vibrations. Finally, it is concluded with the combination of factors that leads to better surface topography, and the following recommended steps are established for this line of research

Estudio del comportamiento térmico del disipador de calor de un extrusor de impresora 3D

Al llarg dels anys, les tecnologies de fabricació additiva per impressió 3D han evolucionat ràpidament fins a l’actualitat. La seva aplicació predominant es la fabricació de prototips o series molt curtes de peces. A més, amb el moviment Open-Source y la gran accessibilitat dels processos de fabricació per impressió 3D com el modelatge per deposició de filament fos han portat aquest tipus de tecnologia fins a aplicacions domèstiques a través de màquines a petita escala. En aquest treball de final de grau s’estudia el comportament tèrmic d’una de les peces clau per a la vida útil d’aquestes màquines: el dissipador de calor. Les impressores 3D arriben a temperatures molt elevades de fins a 250ºC que, en cas de no ser correctament regulada, poden provocar greus problemes al conjunt de la màquina reduint la seva vida útil i funcionalitat. Es per això que s’han realitzat anàlisis computacionals de tres models geomètrics diferents de dissipador per a trobar el més òptim: el que aconsegueixi dissipar més quantitat de calor, per a diferents fluxos d’aire refrigerant provinent d’un ventilador del que estan dotades les impressores 3D. A més, s’han realitzat proves experimentals per a validar els resultats computacionals, combinant finalment els resultats d’ambdues fases d’anàlisi

Enhancing Surface Topology of Udimet®720 Superalloy through Ultrasonic Vibration-Assisted Ball Burnishing

This contribution reports the effects of an ultrasonic-vibration assisted ball burnishing process on the topological descriptors of nickel-based alloy Udimet®720. This material is of high interest for the transportation industry, and specifically for the aeronautical sector. Despite the acknowledged necessity to finish this material to achieve excelling mechanical performances of parts, surface integrity enhancement by means of plastic deformation through ball burnishing has seldom been explored in previous references so far. In this paper, different surface descriptors are used to report how the topology changes after ultrasonic-assisted ball burnishing, and how burnishing conditions influence that change. The burnishing preload and the number of passes are the only influential factors on surface change, whereas the feed velocity of the tool and the strategy reveal not to be relevant on the result. Additionally, the extent to which the process successfully modifies the objective surfaces is highly divergent depending on the original scale of the treated surface. The assistance of the process with vibrations also shows that the resulting topologies are characterized by a periodical pattern of repetitive peaks and valleys that are extended on the surface with a higher frequency in comparison to the non-assisted process, which could influence in the functional deployment of workpieces treated through it, and could deliver an advantage with regard to its non-assisted homologous process