Innovative Propulsion Systems and CFD Simulation for Fixed Wings UAVs

Nowadays, mobile applications demand, in large extent, an improvement in the overall efficiency of systems, in order to diversify the number of applications. For unmanned aerial vehicles (UAVs), an enhancement in their performance translates into larger payloads and range. These factors encourage the search for novel propulsion architectures, which present high synergy with the airframe and remaining components and subsystems, to enable a better UAV performance. In this context, technologies broadly examined are distributed propulsion (DP), thrust split (TS), and boundary layer ingestion (BLI), which have shown potential opportunities to achieve ambitious performance targets (ACARE 2020, NASA N+3). The present work briefly describes these technologies and shows preliminary results for a conceptual propulsion configuration using a set number of propulsors. Furthermore, the simulation process for a blended wing body (BWB) airframe using computational fluid dynamics (CFD) OpenFOAM software is described. The latter is examined due to its advantages in terms of versatility and cost, compared with licensed CFD software. This work does not intend to give a broad explanation of each of the topics, but rather to give an insight into the state of the art in modeling of distributed propulsion systems and CFD simulation using open-source software implemented in UAVs

Scale-adaptive simulation of unsteady cavitation around a naca66 hydrofoil

Distances between consecutive aftershocks are analysed by means of mono- and multifractal theory with the aim of quantifying the complexity of the physical mechanism governing them, as well as their predictability and predictive instability. Hausdorff, Ha, and Hurst, H, exponents are determined by semivariograms and rescaled analysis, respectively. The exponent ß of the power law describing power spectral contents is also quantified. These three parameters permit a generation of fractional Gaussian noise, fGn, simulating distances. The complexity and predictive instability of physical mechanism generating the series of distances is quantified by means of the correlation dimension, µ*, the Kolmogorov entropy, ¿, and the Lyapunov exponents, ¿i, which are based on the reconstruction theorem formulation. Additionally, the multifractal detrended fluctuation analysis, MF-DFA, contributes with a different point of view to quantify the complexity of the series, in terms of fractal spectral width, W, spectral asymmetry, B, and the critical Hölder exponent, a0. By one hand, the MF-DFA is applied to the complete set of distances characterising the whole aftershock process. By the other hand, the MF-DFA is applied to segments of the series of distances with the aim of determining the evolution of the complexity since the mainshock up to the end of the stress relaxation process. Finally, an ARIMA multilinear regression process is applied to obtain some improvements, in comparison with fGn simulations, on the prediction of distances. The database for this analysis is obtained from the Southern California Seismic Network (SCSN) catalogue. Three series of aftershocks equalling to or exceeding magnitudes of 2.0, assuring seismic catalogue completeness, and associated with Landers (06/28/1992), Northridge (01/17/1994) and Hector Mine (10/16/1999) mainshocks are obtained. It is worth mentioning that common mono-multifractal behaviour for the three aftershocks series is not detected, whatever aftershock periods or segments of them are considered.Postprint (published version

Towards a National Innovation System in México Based on Knowledge

In the last years, the research in diverse disciplines has increased the importance of innovation studies at the national level. In this sense, this paper proposes the development of National Innovation Systems (NIS) and its application to the economy in Mexico. Considering the characteristics and limitations of the study region, the mentioned proposal of NIS it is necessary to integrate the study of Knowledge-Based Economies (KBE) approach to study of the different approaches developed about the NIS. In addition, we will analyze the studies about the science, technology and innovation in Mexico, and the availability of these indicators

Gogoetak 'hitzen ordena eta esaldien egitura informatiboaz' prosodiaren laguntzaz

El artículo trata de acercarse a la relación de la prosodia (entonación, duración, pausas, y sobre todo de las unidades básicas de entonación así definidas) con la denominada estructura informativa de la oración, y con diversas estrategias de focalización de sus componentes. Para ello se estudian comparativamente 127 enunciados unioracionales, espontáneos, de autopresentación de 127 hablantes de otras tantas localidades que representan la totalidad de zonas del habla vasca peninsular, así como alguna continental. Enunciados de tipologías y ordenamientos diferenciados, de una lengua de orden típico OV/XV,que se tratan de relacionar con las diversas estructuras prosódicas que ellos presentan. Con base en los diferentes datos, el artículo formula diversas hipótesis de trabajo, tanto particulares referentes a la lengua vasca, como más generales, a confirmar en estudios posteriores

Hitzen ordena eta esaldiaren egitura informatiboa. Gogoeta historiko zenbaiten berri labur. Antzinatea

Grekoen ekarpen linguistikoari buruzko sarrera labur baten ondoren (1), Grezian esaldiaren egituraren inguruan egindako lehen gogoeten berri ematen da (2), Platon eta Aristotelesen itzaletik, eta hausnarketa abiatzen da jada ordudanik nahasian ageri diren hiru ikuspegi, sintaktiko, semantiko, eta informatiboen ildotik. Ondoren, 3. eta 4. ataletan, antzinatetik zuzenean hitzen ordena edota, oro har, esaldiaren egitura informatiboaren inguruan egindako hainbat gogoeten berri ematen da. Gramatikaren ikuspuntutik (3), eta, batez ere, erretorikarenetik (4), beti, gaur egungo alor honetako kezkekin zerikusia izan lezaketen neurrian. Tarteka, euskararen inguruko konparaketaren bat ere, nola 3.5.1 atalean, esaldi amaierako aditzaren inguruko teoriez, latinaren nola euskararen kasuetan

Development of a code in python programming language to generate Ashby chart applied for materials selection

This study focuses on the development of a programming code to generate Ashby charts, which are used to optimize the mechanical design process in terms of reduction the materials selection time. The platform developed was carried out using python programming language and a database composed of 75 different types of materials that have been categorized in 7 regions (metals, ceramics, polymers, elastomer, natural, foams and composites) with their respective mechanical and thermal properties (Young's modulus, density, mechanical strength, thermal conductivity, thermal expansion and maximum service temperature). In order to perform the charts Ashby, the code first generates bubble diagrams in logarithm scale using the range of values of two desired properties, and then, these diagrams are grouped into regions through an envelope that is created using analytic geometry. For validation of the platform and the methodology, the obtained Ashby charts results were contrasted with charts provided by the CES Edupack 2017 software, from there the percentage of differences between the model developed and baseline charts were among of 2,8% to 15%. In consequence, the Ashby Charts obtained with the proposed code they are suitable for use in the selection of material.Este estudio se centra en el desarrollo de un código de programación para generar gráficos Ashby, que se utilizan para optimizar el proceso de diseño mecánico en términos de reducción del tiempo de selección de materiales. La plataforma desarrollada se llevó a cabo utilizando el lenguaje de programación python y una base de datos compuesta por 75 tipos diferentes de materiales que se han categorizado en 7 regiones (metales, cerámicas, polímeros, elastómeros, naturales, espumas y compuestos) con sus respectivas propiedades mecánicas y térmicas ( Módulo de Young, densidad, resistencia mecánica, conductividad térmica, expansión térmica y temperatura máxima de servicio). Para realizar los gráficos Ashby, el código primero genera diagramas de burbujas en escala de logaritmo usando el rango de valores de dos propiedades deseadas, y luego, estos diagramas se agrupan en regiones a través de una envolvente que se crea usando geometría analítica. Para la validación de la plataforma y la metodología, los resultados obtenidos de los gráficos de Ashby se compararon con los gráficos proporcionados por el software CES Edupack 2017, a partir de ahí, el porcentaje de diferencias entre el modelo desarrollado y los gráficos de referencia se encontraban entre el 2,8% y el 15%. En consecuencia, los gráficos de Ashby obtenidos con el código propuesto son adecuados para su uso en la selección de material

Influencia de la edad en el pronóstico del shock cardiogénico isquémico. Resultados de un tratamiento intervencionista temprano

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Cirugía. Fecha de lectura: 08-09-201

Proyecto artístico: “Vitu Valera”

Una de las mejores herramientas multisensoriales no solo de la comunicación, sino de la vida es la música. Desde que tengo uso de razón siempre he estado involucrado con esa expresión artística. A muy corta edad he tocado varios instrumentos y hoy tengo la suerte de poder vivir trabajando en la industria musical y de mi propio proyecto artístico. Creo firmemente que la música es una de las mejores profesiones para mejorar la vida en este planeta. He podido crear así un proyecto musical donde me permito combinar la música tradicional peruana y afrolatina con la música electrónica. Logro expresar a través de un show de música en vivo acompañado de instrumentos electrónicos y orgánicos mi arte que además tiene un concepto visual gracias al uso de proyección de imágenes. En este documento explico cómo a setiembre de 2022 logré desarrollar este proyecto, expongo una breve historia de mi carrera y muestro una serie de conclusiones acerca de lo aprendido durante los años de trayectoria artística

Implicit large eddy simulation of unsteady cloud cavitation around a plane-convex hydrofoil

The present paper focuses on the erosive cavitation behavior around a plane convex hydrofoil. The Zwart-Gerber-Belamri cavitation model is implemented in a library form to be used with the OpenFOAM. The implicit large eddy simulation (ILES) is applied to analyze the three dimensional unsteady cavitating flow around a plane convex hydrofoil. The numerical results in the cases under the hydrodynamic-conditions, which were experimentally tested at the high speed cavitation tunnel of the École Polytechnique Fédérale de Lausanne (EPFL), clearly show the sheet cavitation development, the shedding and the collapse of vapor clouds. It is noted that the cavitation evolutions including the maximum vapor length, the detachment and the oscillation frequency, are captured fairly well. Furthermore, the pressure pulses due to the cavitation development as well as the complex vortex structures are reasonably well predicted. Consequently, it may be concluded that the present numerical method can be used to investigate the unsteady cavitation around hydrofoils with a satisfactory accuracy. © 2015 Publishing House for Journal of Hydrodynamics.Postprint (author's final draft

Pumps as Turbines (PATs) by Analysis with CFD Models

[EN] Pumps as turbines (PATs) are the typical solution for electrification using micro hydropower plants (MHP) in the rural sector. Other engineering applications where lately the use of PATs have increased are irrigation, water supply, and energy recovery systems due to their availability, short delivery time, long service life, economic feasibility, construction, and maintenance advantages. However, selecting the suitable pump(s) is difficult because manufacturers only provide performance curves when operating in pump mode; therefore, there is no universal method to predict that issue. For this reason, theoretical, analytical, experimental, and numerical simulation research have been made to predict these curves and the PATs' performance. The present paper analyzes PATs with Computational Fluid Dynamics (CFD) based on advanced research. For this aim, information from a wide range of types of pumps with different rotation speeds was classified to examine case approaches, computational domains, mesh generation, boundary conditions, optimization of elements, and CFD package used to establish the effectiveness of this tool and to find characteristics which have not been enough investigated at present. Most studies used CFD simulations with ANSYS code and K-¿ turbulence closure model, which presented adequate results. Finally, this paper shows that numerical simulations with CFD analysis were successfully carried out to determine pump performance and predict curves in direct and reverse mode, improving certain components and conducting more profound research on certain specific issues.The authors gratefully acknowledge the financial support provided by Escuela Politécnica Nacional for the development of the project: PIS 19-06, PII-DIM-2019-06, and Process Simulation Laboratory of Mechanical Engineering FacultyPlua, F.; Hidalgo, V.; Cando, E.; Pérez-Sánchez, M.; López Jiménez, PA. (2022). Pumps as Turbines (PATs) by Analysis with CFD Models. International Journal on Advanced Science, Engineering and Information Technology (Online). 12(3):1098-1104. https://doi.org/10.18517/ijaseit.12.3.152901098110412