Topology and Shape optimization for CFD-Computational Fluid Dynamics

On this work a CFD optimization problem is treated from two different points of view -- In one hand, topology optimization using a homogenization method based on the Brinkmann penalization is presented, implemented using the finite elements method and optimized with a mesh adaptation step -- Secondly, a shape optimization method based on Hadamard boundary variation using differentiation with respect to the domain is developed, imple- mented and tested -- Finally, a coupling of both methods taking advantage of their own attributes is proposed and tested -- The expected results are obtaine

Discretized Miller approach to assess effects on boundary layer ingestion induced distortion

The performance of propulsion configurations with boundary layer ingestion (BLI) is affected to a large extent by the level of distortion in the inlet flow field. Through flow methods and parallel compressor have been used in the past to calculate the effects of this aerodynamic integration issue on the fan performance; however high-fidelity through flow methods are computationally expensive, which limits their use at preliminary design stage. On the other hand, parallel compressor has been developed to assess only circumferential distortion. This paper introduces a discretized semi-empirical performance method, which uses empirical correlations for blade and performance calculations. This tool discretizes the inlet region in radial and circumferential directions enabling the assessment of deterioration in fan performance caused by the combined effect of both distortion patterns. This paper initially studies the accuracy and suitability of the semi-empirical discretized method by comparing its predictions with CFD and experimental data for a baseline case working under distorted and undistorted conditions. Then a test case is examined, which corresponds to the propulsor fan of a distributed propulsion system with BLI. The results obtained from the validation study show a good agreement with the experimental and CFD results under design point conditions

Synthetic route to a pincer-tweezer precursor

Treball Final de Grau en Química. Codi: QU0943. Curs acadèmic: 2019/2020The concept of molecular tweezer became popular due to their application in host-guest chemistry in the early 90s by Whitlock and co-workers. [1] A molecular tweezer may be defined as a molecular receptor containing two polyaromatic interaction sites(IS) extended from a more or less rigid connector or spacer (S). [2] [...

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

Wetland Monitoring Using Unmanned Aerial Vehicles with Electrical Distributed Propulsion Systems

The inspection of wetlands in the Ecuadorian highlands has gained importance due to the environmental issues linked to the growth of human activities and the expansion of the agricultural and livestock frontiers. In this sense, unmanned aerial vehicles (UAVs) have been amply used in monitoring activities such as the supervision of threatened ecosystems, where cyclic measurements and high-resolution imagery are needed. However, the harsh operating conditions in the Andean highlands and sensitive ecosystem restrictions demand efficient propulsion configurations with low environmental impact. Electrical distributed propulsion (EDP) systems have surged as a forefront alternative since they offer benefits in both the propulsive and aerodynamic performance of fixed-wing UAVs. In this chapter, an EDP system is sized for a design point at the Andean operating conditions. Thereafter, two propulsion configurations were established based on off-the-shelf components, and their performance was characterized through analytical approaches. These results highlight the trends in power consumption and performance when the number of propulsors is increased. A significant contribution of this work is to exhibit important patterns in the performance of electric propulsion by using commercial components, and to set the operating limitations that can be further explored for analogous configurations in larger UAVs

Manual para la interpretación del perfil de resistividad obtenido al realizar el estudio de la resistividad del suelo a partir de las configuraciones del método de Wenner

Los datos de la resistencia del suelo son el factor clave en el diseño de un sistema de puesta a tierra, para un objetivo de funcionamiento específico. Todo suelo conduce corriente eléctrica, con algunos suelos teniendo una buena conductividad eléctrica mientras que la mayoría tiene conductividad eléctrica inferior. La resistencia del suelo varía extensamente en el mundo entero y cambia dramáticamente dentro de áreas pequeñas. La resistencia del suelo es influenciada principalmente por el tipo de tierra (arcilla, pizarra, etc.), contenido de agua, la cantidad de electrolitos (los minerales y sales disueltas) y finalmente, la temperatura. Al diseñar un sistema de aterramiento para un objetivo de funcionamiento específico, es necesario medir exactamente la resistividad del suelo del sitio donde el sistema de puesta a tierra será instalada. El diseño de sistema de puesta a tierra es un proceso de ingeniería que remueve la conjetura y el “arte” de poner a tierra. Permite que el aterramiento sea hecho de “manera correcta la primera vez”. El resultado es un ahorro en costos evitando los cambios de orden y las “mejoras” de la tierra. Existen diversas técnicas geofísicas, las cuales intentan distinguir o reconocer las formaciones geológicas que se encuentran en profundidad mediante algún parámetro físico, como por ejemplo en sísmica por la velocidad de las ondas o en prospección eléctrica por la resistividad, o en algún caso su inverso, la conductividad. Algunas de estas técnicas más modernas son muy precisas, pero actualmente se sigue utilizando los sondeos eléctricos verticales, dada por su sencillez y relativa economía del equipo necesario

Eficacia de un programa de educación experiencia, en habilidades sociales, del Equipo Femenino de Fútbol Real Academia de Pereira, 2016

El presente trabajo de grado, tuvo como propósito describir los efectos de un programa de educación experiencial, en las habilidades sociales de las jóvenes deportistas del equipo femenino Real Academia. Para dar cumplimiento a este objetivo, se planteó una investigación cuantitativa con un diseño metodológico cuasi-experimental sin grupo control, utilizando un cuestionario de inteligencia emocional como técnica de recolección de información y el análisis del contenido como técnica de análisis. Los sujetos fueron 11 mujeres de un equipo de fútbol femenino de la ciudad de Pereira y con rangos de edad entre los 18 y 35 años. Para la presentación de los resultados se tuvo en cuenta, el cuestionario para la medición de inteligencia emocional de Adriana mercado Tobías y Jimena mercado callejas,el cual está diseñado de la siguiente manera: 7 dimensiones (correspondientes a las 7 habilidades sociales), con un total de 120 ítems. Tales ítems fueron realizados con direccionalidad positiva y negativa con el ánimo de disminuir la aquiescencia. Para la sistematización de la información se utilizó el software SPSS. Los resultados de la investigación mostraron unadiferencia significativa en una de las 7 habilidades (AUTOCONTROL P<0,028), la investigación posee unas características innovadores para la utilización de nuevas metodologías en el campo de la recreación; a pesar de que los resultados estadísticos demostraron que solo se presentó una diferencia significativa, se pudo observar que las deportistas presentaron unos valores altos durante la aplicación de los test en cada habilidad social, encontrando modificaciones positivas entre una y la otra, dando lugar a la importancia de la formación deportiva y personal desde sus hogares que es fundamental para obtener un mejor desenvolvimiento en dichas habilidades; cabe resaltar que siguen siendo susceptibles a poder fortalecerse y mejorar las habilidades sociales, con programas que estén incluidos o hagan parte de los procesos de entrenamiento para así continuar obteniendo mejores resultados