Examinando por Autor "Ladino Ospina, Jair Alexander"

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    Biomechanical modeling of deglutition
    (Universidad del Valle, 2018) Ramírez Parra, Nicolás; Ladino Ospina, Jair Alexander; Hermant, Nicolás
    Swallowing is a physiological process whose malfunction a effects the human quality of life, e.g. malnutrition, dehydration or asphyxia, and has been studied using in vivo approaches. However, advances in computational capacity have encouraged the production of more accurate computational models of offering advantages such as flexibility and reduced experimental costs. Hence, this work proposed the numerical solution of a 2D sagittal swallowing model with physiological accurate tongue's dorsum dynamics based on real time magnetic resonance imaging (RT-MRI) of a healthy young adult. The work designed a full factorial set of simulations and with a second order Box Behnken' surface response design, dimensional relationships were established between food bolus' rheology, swallowing speed, output flow rate, force and shear force over the tongue. Moreover, a dimensionless model was also proposed and exponential behaviors of pressure and friction coefficients as a function of Reynolds numbers were found with an exponential relationship. Such results are intended to predict swallowing flow conditions based on bolus' rheology and the speed of the swallowing event, and also serve as a first validation for more complex models that use other representation techniques. As validation approaches, the work addressed three indirect validations.
  • Miniatura
    PublicaciónAcceso abierto
    BIOMODE : Biomechanical Modeling of Deglutition.
    (Universidad del Valle, 2019-03-07) Collazos Pino, Argemiro; Ladino Ospina, Jair Alexander; Casanova, Gonzalo Fernando; Pierre Hermant, Nicolas; Ramírez Parra, Nicolás; García Posada, Mauricio; Blandón, Juan Camilo; Terán, Leonel Albeiro; Grupo de investigación en Fatiga y Superficies GIFS; Grupo de Investigación en Mejoramiento Industrial GIMI
    Deglutition or swallowing is the process in which, coordinate motion of several muscles transport the food bolus, from the oral cavity to the low esophageal sphincter. This process is composed by several stages such as food bolus preparation, propulsion, pharyngeal and esophageal stages. In general, any physiological or pathological affection to this coordinated process is known as dysphagia, and it is associated with stroke survivors, Parkinson, multiple sclerosis, and in general aged related diseases. Dysphagia severely affects the life quality of the patient and can cause death, mainly to the effects of food bolus aspiration (aspiration pneumonia). This research was done in collaboration with GIPSA-LAB, who work under the macro project “eSwallHoome”, funded by the French Agence Nationale de la Recherche (FANR) The research has as the main objective to study and explain the mechanisms of breathing and swallowing via in vivo, in vitro and in simulacra approaches. The project Biomechanical modeling of deglutition (Biomode) is focused on modeling the behavior of food bolus during the swallowing process. This project aimed to contribute to the understanding of the physical phenomena underlying swallowing. Particularly, this project developed tongue’s elastic models and simplified models related with the interaction of a liquid, Newtonian food bolus and the oral cavity during the oral propulsion stage. The approach of the study was both experimental and computational. The highlights of the project included: 1. Mechanical models of tongue’s motion and deformation based on hyperelastic muscle’s properties. 2. Numerical tools for the simulation of large displacement models coupled with nonlinear elastic materials that would potentially describe the fluid structure interaction during oral propulsion stage and also compare the results with experimental data taken from a simplified bench and 3. Generation of simplified dimensionless models of oral propulsion stage based on the interaction between a Newtonian fluid food bolus and the physiological accurate tongue’s dynamics, responsible for oral propulsion. During the project, GIPSA-Lab/TIMC-IMAG laboratories from Grenoble and Nicolas Hermant from Universidad del Valle, developed a full 3D nonlinear elastic model using finite element method and high displacement models of human tongue biomechanics. Also, a basic fluid structure interaction with Newtonian fluid and a nonlinear latex membrane with high displacement model was implemented in ANSYS® Workbench. Finally, two novel simplified dimensionless models for estimation of fluid/tongue interaction load as function of flow regime and fluid food bolus properties were proposed.
  • Miniatura
    PublicaciónAcceso abierto
    Diseño estructural y aerodinámico de un túnel de viento subsónico con capacidad modular para funcionamiento en régimen transónico y supersónico
    (Universidad del Valle, 2017) Mondragón Duque, Daniela; Valdes Ortiz, Jairo Antonio; Ladino Ospina, Jair Alexander
    La industria aeroespacial es un sector de aplicación de varios campos de la ingeniería, donde se combinan los procesos de sistematización, uso de materiales y aplicación de leyes físicas con el fin de proponer múltiples soluciones a diferentes necesidades. Un aspecto que motiva al desarrollo de esta industria en Colombia es el apoyo en gran medida al desarrollo de la nación, no solo por la cantidad de nuevos empleos que pueden ser generados, de todos los niveles de formación, sino también por la variedad de áreas de conocimiento que son necesarias para su ejercicio y desarrollo de tecnologías implicadas. El proyecto propone el diseño un túnel de viento trisónico tipo blowdown, el cual opera en un rango de velocidades 0,3 a 4 Mach, hace parte de un trabajo de investigación que pretende desarrollar un equipo con características modulares que permita abarcar todo el rango de operación propuesto. El diseño del Túnel de Viento Trisónico de Univalle (TWT-UV) aborda un desarrollo aerodinámico teórico para definir las propiedades de operación en rango subsónico y supersónico, con ello se definen las propiedades de diseño y selección de los elementos cámara de pruebas, cono de contracción, difusor, cámara de estabilización, válvula reguladora de presión (PRV), sistema de abastecimiento y demás accesorios necesarios para su funcionamiento. Las características modulares del túnel se refieren a que presenta diferentes configuraciones de acuerdo a la velocidad a la cual se vaya a experimentar. El diseño del TWT-UV es una propuesta adecuada a las necesidades actuales y la construcción final de la idea brindará a la Universidad del Valle una herramienta para el apoyo de los proyectos de investigación actuales (Verificación de Simulación), para el desarrollo de nuevos proyectos de investigación y formación en el área aerodinámica; y al Clúster Aeroespacial del Valle del Cauca, una herramienta investigativa ineludible para impulsar el sector aeroespacial en el departamento y el país. En general contar con esta herramienta abre la posibilidad a alcanzar nuevos logros en investigación y desarrollo, buscando también producir conocimiento de calidad en esta área y haciendo la práctica actual más consiente y progresista.
  • Miniatura
    PublicaciónAcceso abierto
    Geometry optimization of a francis turbine for efficiency, cavitation and erosion using computational fluid dynamics
    (Universidad del Valle, 2018) Aponte Núñez, Rubén Darío; Rodríguez Pulecio, Sara Aida; Ladino Ospina, Jair Alexander
    In recent years, the application of numerical computational models based on computational fluid dynamics (CFD) to industrial problems has been increasing; Today CFD is used to optimize and develop equipment and processes in many types of industry including the energy industry. The main advantage of the solutions with CFD is in the obtaining of the operating conditions and the analysis of internal and external flows, which experimentally is very difficult and expensive to achieve. This document presents the results of the research project of a master's degree in engineering with an emphasis in mechanical engineering where the geometry that minimizes the erosive wear by hard particle and cavitation for the different operating regimes maintaining the efficiency of the 10MW Francis turbine of the Amaime hydroelectric plant was obtained. To achieve this, a Simplified Virtual Laboratory (SVL) methodology was implemented, consisting of the use of Computational Fluid Dynamics and an optimization technique. First, the simulation of the current geometry of the turbine was carried out to characterize and verify, with experimental data, that the model represents the current operating conditions; this required to generate 3D CAD geometries by means of planes and reverse engineering using three-dimensional scanning of complex elements of the turbine such as blades. Second, it was required to optimize the geometry of the runner blades, guide vanes, covers and labyrinths by the combined use of factorial design of experiments, artificial neural networks (ANN) and optimization techniques by genetic algorithms.