Thermal and hydraulic analysis of multilayered asphalt pavements as active solar collectors

The fulfillment of current environmental aims like reducing fossil fuel consumption or greenhouse gas emissions entails the development of new technologies that enable the use of cleaner, cheaper and renewable energies. Furthermore, the need to improve energy efficiency in buildings encourages scientists and engineers to find new ways of harvesting energy for later uses. The use of asphalt pavements as active solar collectors is introduced in this article. Several authors have studied the use of roads as an energy source before. However, a new technology is presented in which a multilayered pavement with a highly porous middle layer is used instead of a solar collector with an embedded pipe network. These collectors are fully integrated within the road infrastructure and may offer low cost solar energy for water heating. The paper includes a brief comment on the state-of-the-art. Then, a broad methodology is presented in which data, materials and procedures needed to run the tests are fully described. Finally, the results of the laboratory tests are stated and discussed. The prototype used in the laboratory provided excellent thermal efficiency. However, these good results contrast with the low flow rate levels registered during the tests. Thus, although this technology seems to be very promising, new experimental tests should be performed before an effective application is possible.This paper is based on the initial literature review for the Fenix Project. The development of the Fenix Project (www.proyectofenix.es) has been possible thanks to the financial contribution of the Center for Technological and Industrial Development (CDTI) within the framework of the Ingenio 2010 programme, through the CENIT Programme. The companies and research centers involved in the project wish to express their gratitude for the contribution

3D numerical modelling and experimental validation of an asphalt solar collector

Research about renewable technologies for thermal energy collection is crucial when critical problems such as climate change, global warming or environmental pollution are concerned. Transforming solar energy into thermal energy by means of asphalt solar collectors might help to reduce greenhouse gas emissions and fossil fuel consumption. In this paper, a laboratory-scale asphalt solar collector formed by different slabs has been characterized by applying numerical techniques. An experimental test where the thermal performance of the collector was determined for three values of heat exchange fluid flow rate was carried out for the validation of the numerical model. Then, the CFD model was used to analyse the thermal response of the collector according to the following parameters: flow rate, solar irradiance, size and thickness. Results show that increasing values of heat exchange fluid flow rate result in better thermal performances. Likewise, increasing values of irradiance and size of the collector lead to higher values of thermal performance, although other parameters should also be considered for the final design of the system. Finally, under the conditions here considered, the thickness of the collector turned out not to be as significant as expected in relation to its thermal response. The combination of experimental tests and CFD codes can be considered a powerful tool for the characterization of asphalt solar collectors without incurring significant costs related to experimental field tests.This project, with reference BIA2013-40917-R, is financed by the Ministry of Economy, Industry and Competitiveness and funded by the State General Budget and the European Regional Development Fund (FEDER)

Analysis of notch effect in 3D-printed ABS fracture specimens containing U-notches

In this paper a fracture assessment in additive manufactured acrylonitrile butadiene styrene (ABS) fracture specimens containing U-notches is performed. We performed 33 fracture tests and 9 tensile tests, combining five different notch radii (0 mm, 0.25 mm, 0.50 mm, 1 mm and 2 mm) and three different raster orientations: 0/90, 30/-60 and 45/-45. The theory of critical distances (TCD) was then used in the analysis of fracture test results, obtaining additional validation of this theoretical framework. Different versions of TCD provided suitable results contrasting with the experimental tests performed. Moreover, the fracture mechanisms were evaluated using scanning electron microscopy in order to establish relationships with the behaviour observed. It was demonstrated that 3D-printed ABS material presents a clear notch effect, and also that the TCD, through both the point method and the line method, captured the physics of the notch effect in 3D-printed ABS. Finally, it was observed that the change in the fracture mechanisms when introducing a finite notch radius was limited to a narrow band behind the original defect, which appeared in cracked specimens but not in notched specimens.This research received funding from the Spanish Ministry of Science and Innovation, grant PGC2018-095400-B-I00 “Comportamiento en fractura de materiales compuestos nano-reforzados con defectos tipo entalla”

Numerical investigation of truck aerodynamics on several classes of infrastructures

This paper describes the effect of different testing parameters (configuration of infrastructure and truck position on road) on truck aerodynamic coefficients under cross wind conditions, by means of a numerical approach known as Large Eddy Simulation (LES). In order to estimate the air flow behaviour around both the infrastructure and the truck, the filtered continuity and momentum equations along with the Smagorinsky–Lilly model were solved. A solution for these non-linear equations was approached through the finite volume method (FVM) and using temporal and spatial discretization schemes. As for the results, the aerodynamic coefficients acting on the truck model exhibited nearly constant values regardless of the Reynolds number. The flat ground is the infrastructure where the rollover coefficient acting on the truck model showed lowest values under cross wind conditions (yaw angle of 90º), while the worst infrastructure studied for vehicle stability was an embankment with downward-slope on the leeward side. The position of the truck on the road and the value of embankment slope angle that minimizes the rollover coefficient were determined by successfully applying the Response Surface Methodology

Sistema de aceleración del flujo del aire para aerogeneradores

Dispositivo de aceleración del flujo de aire de entrada a un aerogenerador, que comprende un difusor configurado para albergar un aerogenerador sustancialmente a la entrada de dicho difusor en la dirección del flujo del aire. Las superficies exterior e interior de dicho difusor presentan una pluralidad de hendiduras configuradas para transformar la capa límite laminar generada respectivamente en cada una de dichas superficies en capa límite turbulenta.Solicitud: 201201047 (17.10.2012)Nº Pub. de Solicitud: ES2514990A1 (28.10.2014)Nº de Patente: ES2514990B2 (24.03.2015

Dispositivo reductor de velocidad aplicable a vías de circulación

Dispositivo reductor de velocidad aplicable a vías de circulación; que comprende un cuerpo destinado a conformar un resalto en una vía de circulación con, al menos, un módulo (la) provisto de: - una estructura fija de soporte destinada a anclarse al pavimento; - una caja móvil; - un generador piezoeléctrico, montado en el interior de la caja móvil y - un circuito eléctrico; comprendiendo el generador piezoeléctrico una serie de piezoeléctricos dispuestos en voladizo sobre un perfil y conectados entre sí; provocando los movimientos de descenso y de ascenso de la caja móvil la flexión de los piezoeléctricos y la generación de una diferencia de potencial por parte de dichos piezoeléctricos.Solicitud: 201730572 (31.03.2017)Nº Pub. de Solicitud: ES2613752A1 (25.05.2017

Artificial reefs built by 3D printing: systematisation in the design, material selection and fabrication

The recovery of degraded marine coasts and the improvement of natural habitats are current issues of vital importance for the development of life, both marine and terrestrial. In this sense, the immersion of artificial reefs (ARs) in the marine environment is a way to stimulate the recovery of these damaged ecosystems. But it is necessary to have a multidisciplinary approach that analyses the materials, designs and construction process of artificial reefs in order to understand their true impact on the environment. For this reason, this paper presents the manufacture of artificial reefs by 3D printing, proposing designs with a combination of prismatic and random shapes, with different external overhangs as well as inner holes. For the definition of the artificial reef designs, criteria provided by marine biologists and the results obtained from a numerical simulation with ANSYS were taken into account, with which the stability of the artificial reefs on the seabed was analysed. Three dosages of cement mortars and three dosages of geopolymer mortars were studied as impression materials. The studies included determination of the rheological properties of the mortars, to define the printability, determination of the cost of the materials used, and determination of the mechanical strength and biological receptivity in prismatic specimens that were immersed in the sea for 3 months. To evaluate the environmental impact of the materials used in the production of the mortars, a Life Cycle Assessment (LCA) was carried out. In order to choose the mortars that encompassed the best properties studied, Multi-Criteria Decision Making (MCDM) was applied and the two best mortars were used for the manufacture of the artificial reefs. Finally, the advantages and disadvantages of the 3D printing process used were analysed. The results of the studies carried out in this research show that cement mortars have better characteristics for artificial reef applications using 3D printing, and that the technique applied for the manufacture of the artificial reefs allowed the digital models to be faithfully reproduced.This work has been co-financed by the European Regional Development Fund through the Interreg Atlantic Area Programme, under the project “Artificial Reef 3D Printing for Atlantic Area - 3DPARE” (EAPA_174/2016). Besides, the authors want to thank the following companies for their contribution: Solvay, for supplying the fly ash and sodium hydroxide; BASF, for providing the additives used in the research; Abonomar S.L., for providing the seashells sand; FCC ámbito, for providing the crushed recycled glass and Grupo Cementos Portland Valderribas (Mataporquera plant) for providing the cement

Producción y organización industrial (G996). Febrero 2014

Grado en Ingeniería en Electrónica Industrial y Automátic

Producción y organización industrial (G866). Febrero 2014

Grado en Ingeniería Eléctric

Analysis of the aerodynamic performance of a road vehicle in crosswind conditions around different infrastructures, and proposal to improve traffic safety

RESUMEN: En esta tesis doctoral se estudia la afección sobre los coeficientes aerodinámicos de un vehículo de carretera en condiciones de viento lateral de tres configuraciones características de perfiles del terreno y de tableros de viaductos. Además, se analiza la eficacia de tres modelos de barreras cortaviento instaladas en un terraplén con el fin de mejorar la estabilidad de los vehículos en dichas condiciones. Estos estudios se llevaron a cabo aplicando técnicas experimentales, mediante el ensayo en túnel aerodinámico, y numéricas, mediante la simulación por ordenador con el código de dinámica de fluidos computacional FLUENT. En base a ello, se desarrollaron modelos estadísticos que predicen los coeficientes aerodinámicos del vehículo analizado en función de parámetros representativos de la geometría de las infraestructuras. Así, se demuestra que la seguridad del tráfico bajo la acción del viento lateral puede ser mejorada desde el dimensionamiento y configuración de las distintas infraestructuras analizadas.ABSTRACT: The influence of three different structural configurations characteristic of terrain profiles and viaducts boards on the aerodynamic coefficients of a road vehicle in crosswind conditions is studied in this thesis. Besides, the performance of three models of wind fences installed on an embankment is analyzed with the purpose of improving vehicle stability under such conditions. These studies were carried out using experimental techniques, through wind tunnel testing and numerical, by computer simulation with the computational fluid dynamics code FLUENT. Consequently, statistical models that predict the aerodynamic coefficients of the vehicle analyzed, depending on parameters representing the geometry of the infrastructure were developed. Thus, it is demonstrated that the traffic safety under the action of crosswind can be improved by means of the sizing and configuration of the different infrastructures analyzed