Turbulence Transport in Rotor-Stator and Stator-Rotor Stages of Axial Flow Fans

Turbulence analysis in turbomachines is a complex task. The combination of different turbulence sources and transport mechanisms poses the question of determining adequate metrics to quantify turbulence levels and provide insight into the flow structure and its evolution. Apart from experimental measurement techniques, numerical techniques arise as a useful tool to characterize this type of flow, especially hybrid LES techniques that allow a highly accurate description of the transport of turbulent structures, while turbulence generation at solid boundaries is addressed using RANS schemes. In this chapter, recent developments concerning numerical simulation of rotor-stator and stator-rotor interactions in low-speed axial fans using LES techniques are presented. A post-processing framework is introduced to segregate the deterministic and turbulent components of the unsteady flow, allowing an accurate description of both phenomena. Hence, turbulent transport over the different stage rows of the axial fan can be accurately addressed. Following, LES capacities to simulate turbulence transport mechanisms such as breaking-up of turbulent eddies, stretching and dissipation of vorticity or identification and convection of coherent vortices are discussed. The ability of LES computations to disclose flow turbulence in rotor-stator environments at off-design conditions is specially illustrated

Turbulence structure around an asymmetric high-lift airfoil for different incidence angles

An exhaustive investigation of the structure of the turbulence around an asymmetric FX 63-137 wind turbine airfoil is carried out in this paper. Reliable hot-wire velocity measurements, made at the Xixon Aeroacoustic Wind Tunnel, are presented with the aim of analyzing the turbulent flow features. The probe was placed at two different positions along the streamwise direction, one over the airfoil and the other at the wake, both on the suction and pressure side. These measurements were performed in order to capture the evolution of the flow and its behavior at the wake. The experimental data were collected at a Reynolds number of 350000 for several incidence angles to explore their influence in the turbulence characteristics. The data processing from the dual hot-wire, capable of measuring two velocity components, allowed to achieve half set of the Reynolds stresses, the turbulence intensity and the degree of anisotropy. The boundary layer and wake size were estimated from the Reynolds stress components. In addition, the production term of the turbulence kinetic energy budget is calculated to visualize the unsteadiness energy inside the boundary layer. As a result of these analyses, it was observed that the transversal fluctuations were higher than the longitudinal ones. Besides, an alternative description of the turbulence structure is obtained when a frequency analysis of the motion is provided, disclosing a clear change in the spectra tendencies in the wake and boundary layer regions. This analysis, combined with the degree of anisotropy analysis, was helpful to define a transition zone between the clearly distinguishable instability zone and the free-stream zone. Finally, the integral length scale of turbulence was estimated from the area under the autocorrelation function of the velocity fluctuations. The combination of the results of this work have provided a wide description of the turbulent behavior of the flow around the airfoil and present a clearer physical picture of the phenomena.Gobierno del Principado de Asturias, beca predoctoral Severo Ochoa BP1306

Ludificación de la Historia de Veterinaria: Fase II

En esta convocatoria se ha aprovechado la experiencia del anterior proyecto y se ha continuado con la metodología de la ludificación o gamificación como herramienta de aprendizaje mejorando y adaptando más aun la metodología a los fines de docencia del grado. Se ha logrado incrementar la motivación entre el alumnado y se ha añadido un nuevo componente: el efecto integrador o identitario del alumnado, profesorado y PAS con la profesión y el centro. Los productos obtenidos como material audiovisual y textos y las representaciones se han expuesto en actos conmemorativos o celebraciones del centro. Por otro lado se ha incrementado el repositorio de material didáctico que con cada proyecto se elabora. En este nuevo proyecto se han realizado interpretaciones histórico-teatrales de personajes relevantes en la historia de la veterinaria, realizadas por los propios alumnos matriculados y profesores, abordando distintas problemáticas de profesionales o en diferentes períodos históricos. Entre los productos elaborados están los textos con los guiones elaborados, 9 videos con escenificaciones y 20 breves presentaciones de personajes. Otro de los productos finales en formato de video de 6,19 minutos de duración se ha presentado ante la comunidad universitaria en la Gala atrévete de la Facultad de Veterinaria de 2019, ante más de doscientos alumnos y profesores. Los productos y el proyecto han sido presentados dentro de una comunicación oral en el XXIV Congreso Nacional y XV Iberoamericano de Historia de la Veterinaria que tuvo lugar en Almería del 26 al 28 de octubre de 2018. El impacto del proyecto se ha podido verificar a lo largo de los meses de escenificación por el nivel de actividad de las redes sociales entre los alumnos y la asistencia de más profesores y alumnos incluso no involucrados, con deseo de aprender y ver esta nueva herramienta docente

CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

Aerodynamic Design of a Small-Scale Model of a Vertical Axis Wind Turbine

Wind tunnel testing of small-scale models is one of the most useful techniques to predict the performance of real-scale applications. In this work, the aerodynamic design and the construction of a small-scale model of a straight-bladed vertical axis wind turbine for wind tunnel testing has been performed. Using a double multiple streamtube model (DMST), different solidity values for the turbine and different airfoil geometries were compared to select the final design. Once an optimal design was selected, a numerical simulation using Computational Fluid Dynamics (CFD) was performed in order to obtain a more precise description of the flow field as well as the performance of the model. Future work will comprise the characterization of the model and the comparison of the experimental and numerical results

Proposal of an Optimized Airfoil Geometry for Vertical-Axis Wind Turbine Applications

In this work, an airfoil geometry optimized for vertical-axis wind turbine applications is presented. Different airfoil shapes have been analyzed with JavaFoil, a panel method software. Then, the results from the analysis have been used to optimize the performance of the proposed airfoil shape (UO-17-LDA). This airfoil presents a high lift-to-drag ratio and a delayed stall angle with respect to the original FX-63-137 airfoil, making it suitable for vertical-axis wind turbine applications. The practicality of JavaFoil for the comparison of different airfoil geometries has been verified, as it is capable of obtaining results for a wide number of flow conditions in small computational times and with a user-friendly interface. Nevertheless, the results diverge from the actual solution for high angles of attack (beyond stall)

Optimized design of aerodynamic airfolis for vertical axis wind turbines

Tesis con mención internacionalAbstract The current world context demands a change towards environmentally friendly energy sources. Luckily, the interest on renewable energy sources has been constantly increasing over the past years. Nowadays, wind energy represents one of the most economical options, employing a totally mature harvesting technology. Due to their higher energy output, horizontal-axis wind turbines have been traditionally the preferred option. Nevertheless, vertical-axis wind turbines are becoming relevant, specially in urban areas. Their advantages evidence the need of further research to overcome the main drawbacks that prevent their implantation. The main objective of this thesis is the development of scientific-technological knowledge applicable to the design of optimized vertical-axis wind turbines. As an ultimate goal, transfer of this knowledge is foreseen to small and medium-sized enterprises. Firstly, a literature survey about wind power extraction systems has been performed, focusing afterwards in vertical-axis wind turbines, their advantages, disadvantages and research interest. Then, the design and analysis techniques applicable to vertical-axis wind turbines have been reviewed. Afterwards, an analytical model based on streamtube theory has been developed to predict the performance of prospective turbine designs, being able to predict the whole power curve in computational times in the order of minutes. The model has been used to analyze the influencing parameters in the turbine performance, proposing optimal values of these parameters and the optimal characteristics that an airfoil should possess to be suitable for practical applications of these turbines. Subsequently, the focus has been set on Computational Fluid Dynamics models for the study of the aerodynamic performance and the flow field developed by both a vertical-axis wind turbine and an isolate typical turbine airfoil. Guidelines for the numerical simulation of both turbines and airfoils are provided. Additionally, the main flow unsteadiness generation mechanisms, flow field regions and instabilities have been identified. Insight into the loss of performance of these turbines due to fluid dynamics phenomena has been also provided. Finally, all the generated knowledge has been applied to the design of a small-scale turbine model, developing a procedure for the in-house fabrication of turbine blades and an experimental procedure to estimate the aerodynamic performance of the turbine. Hot-wire measurements have been performed in the turbine wake. The experimental results have verified the methodologies developed in this thesis. Finally, the main findings and implications of this study are discussed, and future research possibilities are outlined. El contexto global actual demanda un cambio hacia fuentes de energía más respetuosas con el medio ambiente. Afortunadamente, el interés hacia fuentes de energía renovables ha estado aumentando de forma continua durante los últimos años. Hoy en día, la energía eólica representa una de las opciones más económicas, al utilizar una tecnología de aprovechamiento totalmente madura. Debido a su mayor producción de energía, las turbinas eólicas de eje horizontal han sido tradicionalmente la opción preferida. Sin embargo, las turbinas de eje vertical están ganando importancia, especialmente en entornos urbanos. Sus ventajas evidencian la necesidad de realizar un esfuerzo en investigación para superar las dificultades que impiden su proliferación. El principal objetivo de esta tesis es el desarrollo de conocimiento científico-tecnológico aplicable al diseño de turbinas eólicas de eje vertical optimizadas. Como fin último, se plantea la transferencia de este conocimiento a pequeñas y medianas empresas. Primero se ha realizado una revisión del estado del arte respecto a los sistemas de extracción de energía eólica, para después centrarse en las turbinas eólicas de eje vertical, sus ventajas, desventajas y el interés de su investigación. Después, se han revisado las técnicas de diseño y análisis aplicables a estas turbinas. Posteriormente, se ha desarrollado un modelo analítico basado en la teoría de tubos de corriente para predecir las prestaciones de distintos diseños de turbinas, siendo capaz de predecir la curva de potencia completa en tiempos computacionales del orden de minutos. El modelo se ha utilizado para analizar los parámetros que influyen en las prestaciones de estas turbinas, proponiendo valores óptimos de dichos parámetros y las características óptimas que un perfil aerodinámico debería poseer para ser utilizado en aplicaciones relacionadas con este tipo de turbinas. Más adelante, se ha centrado la investigación en modelos de Dinámica de Fluidos Computacional para estudiar las prestaciones aerodinámicas y el campo fluido generado por una turbina eólica de eje vertical y un perfil aislado, típico de esta clase de turbinas. Se han proporcionado indicaciones para la simulación numérica tanto de turbinas como de perfiles. Además, se han identificado los principales mecanismos de generación de inestabilidades en el flujo y las regiones e inestabilidades en el campo fluido. También se ha proporcionado una visión acerca de la pérdida de rendimiento de estas turbinas debido a fenómenos fluidodinámicos. Finalmente, todo el conocimiento generado se ha aplicado al diseño de un modelo a escala reducida de una turbina, desarrollando un procedimiento para la fabricación de las palas de la turbina y un procedimiento experimental para estimar el rendimiento aerodinámico de la turbina. Se han realizado medidas de anemometría térmica en la estela de la turbina. Los resultados experimentales han servido para verificar las metodologías desarrolladas en esta tesis. Finalmente, se discuten los principales resultados e implicaciones de este estudio, esbozando posibles líneas de investigación futuras