142 research outputs found
Streakline-based closed-loop control of a bluff body flow
A novel closed-loop control methodology is introduced to stabilize a cylinder wake flow based on images of streaklines. Passive scalar tracers are injected upstream the cylinder and their concentration is monitored downstream at certain image sectors of the wake. An AutoRegressive with eXogenous inputs mathematical model is built from these images and a Generalized Predictive Controller algorithm is used to compute the actuation required to stabilize the wake by adding momentum tangentially to the cylinder wall through plasma actuators. The methodology is new and has real-world applications. It is demonstrated on a numerical simulation and the provided results show that good performances are achieved.Fil: Roca, Pablo Daniel. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; ArgentinaFil: Cammilleri, Ada. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; ArgentinaFil: Duriez, Thomas Pierre Cornil. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; ArgentinaFil: Mathelin, Lionel. Centre National de la Recherche Scientifique. Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur; FranciaFil: Artana, Guillermo Osvaldo. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Toward Shape Optimization of Soft Robots
International audienceIn this paper we present our work on shape optimization for soft robotics where the shape is optimized for a given soft robot usage. To obtain a parametric optimization with a reduced number of parameters, we rely on an approach where the designer progressively refines the parameter space and the fitness function until a satisfactory design is obtained. In our approach, we automatically generate FEM simulations of the soft robot and its environment to evaluate a fitness function while checking the consistency of the solution. Finally, we have coupled our framework to an evolutionary optimization algorithm, and demonstrated its use for optimizing the design of a deformable leg of a locomotive robot
Caractérisation de la croissance transitoire de perturbations 3D stationnaires introduites par des générateurs de vortex dans une couche limite. Application au contrôle d'un écoulement décollé.
Nous étudions expérimentalement l’influence
de Générateurs de Vortex (GV) sur les propriétés d’une couche limite sur plaque plane
ainsi que sur un écoulement décollé. Nous caractérisons l’évolution spatiale des
perturbations 3D stationnaires dans une couche limite sur plaque plane en fonction du
nombre de Reynolds et de l’espacement des GVs. Nous caractérisons ensuite l’influence de
ces perturbations sur l’écoulement décollé sur une paroi courbe
Ventilator output splitting interface ‘ACRA’: Description and evaluation in lung simulators and in an experimental ARDS animal model
The current COVID-19 pandemic has led the world to an unprecedented global shortage of ventilators, and its sharing has been proposed as an alternative to meet the surge. This study outlines the performance of a preformed novel interface called’ACRA’, designed to split ventilator outflow into two breathing systems. The’ACRA’ interface was built using medical use approved components. It consists of four unidirectional valves, two adjustable flow-restrictor valves placed on the inspiratory limbs of each unit, and one adjustable PEEP valve placed on the expiratory limb of the unit that would require a greater PEEP. The interface was interposed between a ventilator and two lung units (phase I), two breathing simulators (phase II) and two live pigs with heterogeneous lung conditions (phase III). The interface and ventilator adjustments tested the ability to regulate individual pressures and the resulting tidal volumes. Data were analyzed using Friedman and Wilcoxon tests test (p < 0.05). Ventilator outflow splitting, independent pressure adjustments and individual tidal volume monitoring were feasible in all phases. In all experimental measurements, dual ventilation allowed for individual and tight adjustments of the pressure, and thus volume delivered to each paired lung unit without affecting the other unit’s ventilation—all the modifications performed on the ventilator equally affected both paired lung units. Although only suggested during a dire crisis, this experiment supports dual ventilation as an alternative worth to be considered.Fil: Otero, Pablo Ezequiel. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Cátedra de AnestesiologÃa y AlgiologÃa; ArgentinaFil: Tarragona, Lisa. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Cátedra de AnestesiologÃa y AlgiologÃa; ArgentinaFil: Zaccagnini, Andrea Silvia. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Cátedra de AnestesiologÃa y AlgiologÃa; ArgentinaFil: Verdier, Natali. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Cátedra de AnestesiologÃa y AlgiologÃa; ArgentinaFil: Ceballos, Martin. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Cátedra de AnestesiologÃa y AlgiologÃa; ArgentinaFil: Gogniat, Emiliano. Sociedad Argentina de Terapia Intensiva.; ArgentinaFil: Cabaleiro, Juan Martin. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; ArgentinaFil: D'adamo, Juan Gastón Leonel. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; ArgentinaFil: Duriez, Thomas Pierre Cornil. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; ArgentinaFil: Garcia Eijo, Pedro Manuel. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; ArgentinaFil: Artana, Guillermo Osvaldo. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de IngenierÃa. Departamento de IngenierÃa Mecánica. Laboratorio de Fluidodinámica; Argentin
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