Open Access
Experimental measurement of the thermal conductivity of fused deposition modeling materials with a DTC-25 conductivity meter
(MDPI, 2023) Rodríguez García, Antonio; Fuertes Bonel, Juan Pablo; Oval Trujillo, Añaterve; Pérez Artieda, Miren Gurutze; Ingeniería; Ingeniaritza
The expansion and low cost of additive manufacturing technologies have led to a revolution in the development of materials used by these technologies. There are several varieties of materials that can be used in additive manufacturing by fused deposition modeling (FDM). However, some of the properties of these materials are unknown or confusing. This article addresses the need to know the thermal conductivity in different filaments that this FDM technology uses, because there are multiple applications for these additive manufacturing products in the field of thermal insulation. For the study of thermal conductivity, the DTC-25 commercial conductivity measurement bench was used, where the tests were carried out on a set of seven different materials with 100% fabrication density—from base materials such as acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA), to materials with high mechanical and thermal resistance such as thermoplastic polyurethane (TPU), polyether ether ketone (PEEK), and high-performance polyetherimide thermoplastic (ULTEM), to materials with metal inclusions (aluminum 6061) that would later be subjected to thermal after-treatments. This study shows how the parts manufactured with aluminum inclusions have a higher thermal conductivity, at 0.40 ± 0.05 W/m·K, compared to other materials with high mechanical and thermal resistance, such as TPU, with a conductivity of 0.26 ± 0.05 W/m·K.
Open Access
High fidelity CFD models comparison to potential flow method in the simulation of full scale floating platform under free decay tests
(Elsevier, 2025-05-01) Gil Liberal, Miguel; Armañanzas Goñi, Javier; Torres Salcedo, Alexia; Fuertes Bonel, Juan Pablo; Campaña, Guillén; Méndez López, Beatriz; León Iriarte, Javier; Ingeniería; Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
The use of simulation models based on potential flow is widespread in the wind industry for the simulation of floating wind turbines. However, these analytical models have shortcomings in correctly representing the behavior of Floating Offshore Wind Turbines (FOWTs) under extreme wind and wave conditions. High fidelity Computational Fluid Dynamics (CFD) simulations aim to develop models where the fluid-structure interaction is more accurately modeled, allowing to correctly predict the behavior of wind turbines and thus to redesign structural components and save costs. In this paper, two different CFD simulation models are developed and compared, including different turbulence models (Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES)), numerical methodologies (Navier-Stokes and Lattice-Boltzmann method) and mooring models (Quasi-Static and Dynamic). Different free decay Load Cases (LC) are performed in XFlow and OpenFOAM, and the damping ratio and natural period of the system are analyzed with different mooring arrangements (Multi-Point Mooring (MPM) and Single-Point Mooring (SPM)), comparing all results with respect to a potential flow model (HydroDyn). A maximum error of 3.3 % in natural period and 1.6 % error in damping factor is obtained, small enough to validate the results of CFD models. Vorticity is also analyzed to understand the differences between both CFD models. Finally, the stress of the mooring lines is computed, which allows validating the mooring system model implemented in XFlow by means of external functions.
Open Access
Designing multifunctional protective PVC electrospun fibers with tunable properties
(MDPI, 2020) Rivero Fuente, Pedro J.; Rosagaray Burdaspar, Iker; Fuertes Bonel, Juan Pablo; Rodríguez Trías, Rafael; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA1929
In this work, the electrospinning technique is used for the fabrication of electrospun functional fibers with desired properties in order to show a superhydrophobic behavior. With the aim to obtain a coating with the best properties, a design of experiments (DoE) has been performed by controlling several inputs operating parameters, such as applied voltage, flow rate, and precursor polymeric concentration. In this work, the reference substrate to be coated is the aluminum alloy (60661T6), whereas the polymeric precursor is the polyvinyl chloride (PVC) which presents an intrinsic hydrophobic nature. Finally, in order to evaluate the coating morphology for the better performance, the following parameters-such as fiber diameter, surface roughness (Ra, Rq), optical properties, corrosion behavior, and wettability-have been deeply analyzed. To sum up, this is the first time that DoE has been used for the optimization of superhydrophobic or anticorrosive surfaces by using PVC precursor for the prediction of an adequate surface morphology as a function of the input operational parameters derived from electrospinning process with the aim to validate better performance.
Open Access
Analysis of tribological properties in disks of AA-5754 and AA-5083 aluminium alloys previously processed by equal channel angular pressing and isothermally forged
(MDPI, 2020) Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; Puertas Arbizu, Ignacio; Salcedo Pérez, Daniel; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Ingeniería; Ingeniaritza
In the present study, the wear behaviour of two aluminium alloys (AA‐5754 and AA‐5083) is analysed where these have been previously processed by severe plastic deformation (SPD) with equal channel angular pressing (ECAP). In order to achieve the objectives of this study, several disks made of these alloys are manufactured by isothermal forging from different initial states. The microstructures of the initial materials analysed in this study have different accumulated deformation levels. In order to compare the properties of the nanostructured materials with those which have not been ECAP‐processed, several disks with a height of 6 mm and a diameter of 35 mm are manufactured from both aluminium alloys (that is, AA‐5754 and AA‐5083) isothermally forged at temperatures of 150 and 200 °C, respectively. These thus‐manufactured disks are tested under a load of 0.6 kN, which is equivalent to a stress mean value of 18 MPa, and at a rotational speed of 200 rpm. In order to determine the wear values, the disks are weighed at the beginning, at 10,000 revolutions, at 50,000 revolutions and at 100,000 revolutions, and then the volume‐loss values are calculated. This study was carried out using specific equipment, which may be considered to have a block‐on‐ring configuration, developed for testing in‐service wear behaviour of mechanical components. From this, the wear coefficients for the two materials at different initial states are obtained. In addition, a comparison is made between the behaviour of the previously ECAP-processed aluminium alloys and those that are non‐ECAP‐processed. A methodology is proposed to determine wear coefficients for the aluminium alloys under consideration, which may be used to predict the wear behaviour. It is demonstrated that AA‐5754 and AA‐5083 aluminium alloys improve wear behaviour after the ECAP process compared to that obtained in non‐ECAP‐processed materials.
Open Access
Modelización y estudio experimental y mediante CFD de un ventilador para alumnos de Grado en Ingeniería Mecánica y de Tecnologías Industriales
(Dykinson, 2021) Fuertes Bonel, Juan Pablo; Torres Salcedo, Alexia; Rivero Fuente, Pedro J.; Armañanzas Goñi, Javier; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
El trabajo planteado en esta comunicación tiene como principales objetivos por un lado, el conocimiento del funcionamiento un ventilador y por el otro, el empleo de softwares propios del diseño (CAD) y de la Mecánica de Fluidos (CFD). Con esto, se busca que el alumno amplíe y afiance sus conocimientos de una máquina fluidomecánica vista en el aula y también, que aprecie la importancia que tiene en ingeniería el trabajo multidisciplinar. Se ha escogido un ventilador, ya que por un lado, su modelización en CAD es más sencilla frente a otras máquinas hidráulicas, como puede ser una bomba centrífuga, y por el otro, porque dentro de las asignaturas de los distintos grados, el estudio del ventilador se realiza en menor profundidad, que el de las máquinas hidráulicas. El trabajo del alumno consta de tres partes diferenciadas: experimentación, diseño y simulación mediante CFD. En la experimentación, el objetivo es que el alumnado pueda manipular un ventilador en el laboratorio contrastando lo visto en teoría con la realidad, y que mediante una toma de datos establecida previamente, se familiarice con su funcionamiento. El siguiente paso consiste en diseñar en CAD la máquina y de esta manera, que puedan poner en práctica lo aprendido en asignaturas anteriores, en cuanto a diseño en CAD se refiere. Por último, y como complemento a las clases sobre CFD, que se imparten en la asignatura donde está programado este trabajo, se pide que el alumnado sea capaz de simular el funcionamiento del ventilador experimentado.
Open Access
Study and optimization of the punching process of steel using the Johnson-Cook damage model
(MDPI, 2024) Claver Alba, Adrián; Hernández Acosta, Andrea; Barba Areso, Eneko; Fuertes Bonel, Juan Pablo; Torres Salcedo, Alexia; García Lorente, José Antonio; Luri Irigoyen, Rodrigo; Salcedo Pérez, Daniel; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
Sheet metal forming processes are widely used in applications such as those in the automotive or aerospace industries. Among them, punching is of great interest due to its high productivity and low operating cost. However, it is necessary to optimize these processes and adjust their parameters, such as clearance, shear force or tool geometry, to obtain the best finishes and minimize crack generation. Thus, the main objective of this research work is to optimize the punching process to achieve parts that do not require subsequent processes, such as deburring, by controlling the properties of the starting materials and with the help of tools such as design of experiments and simulations. In the present study, tensile tests were performed on three steels with different compositions and three sample geometries. The information obtained from these tests has allowed us to determine the parameters of the Johnson-Cook damage criteria. Moreover, punching was performed on real parts and compared with simulations to analyze the percentage of burnish surface. The results obtained show that the methodology used was correct and that it can be extrapolated to other types of die-cutting processes by reducing the percentage of surface fractures and predicting the appearance of cracks. Furthermore, it was observed that clearance has a greater influence than processing speed, while the minimum percentage of the burnish area was observed for the minimum values of clearance.
Open Access
Design and experimentation of a hydrokinetic turbine for electricity generation in closed pipes
(World Scientific and Engineering Academy and Society, 2024) Armañanzas Goñi, Javier; Alcalá, Marina; Fuertes Bonel, Juan Pablo; León Iriarte, Javier; Torres Salcedo, Alexia; Gil Liberal, Miguel; Ingeniería; Ingeniaritza
In the present research work, a device for electrical energy generation to be used in water pipelines has been designed, simulated, and tested. To achieve this, a study of the most influential parameters involved in the experiment has been carried out and both, the turbine model and the geometry of the experimental test pipe, have been selected through CFD simulations. Next, the Design of Experiments (DOE) has been used to obtain the configuration with a higher energy extraction from running water. Finally, the turbine and the test pipe section have been manufactured by 3D printing and the experimental tests have been carried out with the optimal configuration to validate the results obtained in the CFD simulations. To simulate the exchange of energy between the water and the turbine, the CFD software SIMULIA XFlow has been used.
Open Access
Experimental and FEM analysis of wear behaviour in AA5083 ultrafine-grained cams
(MDPI, 2020) Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; Fuertes Bonel, Juan Pablo; León Iriarte, Javier; Salcedo Pérez, Daniel; Puertas Arbizu, Ignacio; Ingeniería; Ingeniaritza
Severe plastic deformation (SPD) processes have attracted a great deal of both scientific and technological interest over the last few years as a consequence of the improvements that are possible to obtain in the microstructure and mechanical properties of the materials manufactured through the use of these kind of processes. However, the practical applications of such materials to obtain mechanical components are significantly fewer. As a direct consequence, the same thing has been observed in the development of studies that show the in-service behaviour of the mechanical components developed in this way. Since one of the industrial objectives of these SPD processes is to obtain functional parts, it is necessary to carry out studies to fill this gap. Therefore, in this study, an analysis of the wear that cams undergo when manufactured from an AA5083 aluminium-magnesium alloy is carried out. The cams were isothermally-forged from materials with and without previous SPD processing by equal channel angular pressing (ECAP). Subsequently, the wear behaviour of these cams was analysed by using specific equipment, which may have been considered to have a block-on-ring configuration, developed for testing in-service wear behaviour of mechanical parts. From this comparative wear study with cams, it is shown that previously-processed materials by ECAP have a better wear performance. Moreover, finite element modelling (FEM) simulations were also included to predict wear in the cams processed in this way. A good agreement between FEM and experimental results was obtained. It is this aspect of performing the wear tests on functional and real mechanical components, and not on laboratory samples, which makes this present research work novel.
Open Access
Modeling experimental parameters for the fabrication of multifunctional surfaces composed of electrospun pcl/zno-nps nanofibers
(MDPI, 2021) Rivero Fuente, Pedro J.; Fuertes Bonel, Juan Pablo; Vicente Gómara, Adrián; Mata Ruiz, Álvaro; Monteserín, María; Rodríguez Trías, Rafael; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA1929
In this work, a one-step electrospinning technique has been implemented for the design and development of functional surfaces with a desired morphology in terms of wettability and corrosion resistance by using polycaprolactone (PCL) and zinc oxide nanoparticles (ZnO NPs). The surface morphology has been characterized by confocal microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (WCA), whereas the corrosion resistance has been evaluated by Tafel polarization curves. Strict control over the input operational parameters (applied voltage, feeding rate, distance tip to collector), PCL solution concentration and amount of ZnO NPs have been analyzed in depth by showing their key role in the final surface properties. With this goal in mind, a design of experiment (DoE) has been performed in order to evaluate the optimal coating morphology in terms of fiber diameter, surface roughness (Ra), water contact angle (WCA) and corrosion rate. It has been demonstrated that the solution concentration has a significant effect on the resultant electrospun structure obtained on the collector with the formation of beaded fibers with a higher WCA value in comparison with uniform bead-free fibers (dry polymer deposition or fiber-merging aspect). In addition, the presence of ZnO NPs distributed within the electrospun fibers also plays a key role in corrosion resistance, although it also leads to a decrease in the WCA. Finally, this is the first time that an exhaustive analysis by using DoE has been evaluated for PCL/ZnO electrospun fibers with the aim to optimize the surface morphology with the better performance in terms of corrosion resistance and wettability.
Open Access
CES EduPack: una herramienta informática para motivar e inspirar el conocimiento de las aleaciones metálicas en alumnos de Ingeniería
(Dykinson, 2021) Armañanzas Goñi, Javier; Torres Salcedo, Alexia; Fuertes Bonel, Juan Pablo; Rivero Fuente, Pedro J.; Ingeniería; Ingeniaritza
La Ingeniería de los Materiales se puede definir como la rama de la Ciencia que estudia la composición y la estructura de los materiales, así como de la forma en que estos factores se relacionan con sus propiedades o su comportamiento en servicio. Debido a ello, la base de la Ingeniería de los Materiales se basa en establecer una relación directa entre la estructura (bien cristalina o amorfa) y su correspondencia con las propiedades finales de distinta índole tales como físicas, mecánicas, ópticas, químicas o térmicas. Este conocimiento resulta de gran interés por tres motivos principales. El primero es que te permite conocer las características de los materiales y te sirve de ayuda para el estudio de aplicaciones específicas. En segundo lugar, se puede conocer en mayor medida los efectos asociados a los distintos procesos de fabricación y relacionarlos con una microestructura específica. Por último, en tercer lugar, permite a un Ingeniero saber utilizar el material más adecuado en función de las condiciones de servicio en un campo de aplicación determinado.