Examinando por Materia "DINAMICA DE FLUIDOS"

Mostrando1 - 9 de 9
  • Artículo de Publicación Periódica
    A combined experimental-computational approach for spatial protection efficacy assessment of controlled release devices against mosquitoes (Anopheles)
    (2018-03) Bernier, Ulrich R.; Kline, Daniel L.; Abad Vázquez, Agustín; Perry, Melynda; Cohnstaedt, Lee W.; Gurman, Pablo; D'hers, Sebastián; Elman, Noel M.
    "This work describes the use of entomological studies combined with in silico models (computer simulations derived from numerical models) to assess the efficacy of a novel device for controlled release of spatial repellents. Controlled Release Devices (CRDs) were tested with different concentrations of metofluthrin and tested against An. quadrimaculatus mosquitoes using arm-in cage, semi-field, and outdoor studies. Arm-in-cage trials showed an approximate mean values for mosquito knockdown of 40% and mosquito bite reduction of 80% for the optimal metofluthrin formulation for a 15-minute trial. Semi-field outdoor studies showed a mean mortality of a 50% for 24 hour trial and 75% for a 48 hour trial for optimal concentrations. Outdoors studies showed an approximate mean mortality rate of 50% for a 24 hour trial for optimal concentrations. Numerical simulations based on Computational Fluid Dynamics (CFD) were performed in order to obtain spatial concentration profiles for 24 hour and 48 hour periods. Experimental results were correlated with simulation results in order to obtain a functional model that linked mosquito mortality with the estimated spatial concentration for a given period of time. Such correlation provides a powerful insight in predicting the effectiveness of the CRDs as a vector-control tool. While CRDs represent an alternative to current spatial repellent delivery methods, such as coils, candles, electric repellents, and passive emanators based on impregnated strips, the presented method can be applied to any spatial vector control treatment by correlating entomological endpoints, i.e. mortality, with in-silico simulations to predict overall efficacy. The presented work therefore presents a new methodology for improving design, development and deployment of vector-control tools to reduce transmission of vector-borne diseases, including malaria and dengue."
  • Artículo de Publicación Periódica
    Controlled release spatial repellent devices (CRDs) as novel tools against malaria transmission: a semi‑field study in Macha, Zambia
    (2018-11) Stevenson, Jennifer C.; Simubali, Limonty; Mudenda, Twig; Cardol, Esther; Bernier, Ulrich R.; Abad Vázquez, Agustín; Thuma, Philip E.; Norris, Douglas E.; Perry, Melynda; Kline, Daniel L.; Cohnstaedt, Lee W.; Gurman, Pablo; D'hers, Sebastián; Elman, Noel M.
    "The emergence of mosquitoes that can avoid indoor-deployed interventions, such as treated bed nets and indoor residual spraying, threatens the mainstay of malaria control in Zambia. Furthermore, the requirement for high coverage of these tools poses operational challenges. Spatial repellents are being assessed to supplement these vector control tools, but limitations exist in the residual effect of the repellent and the need for external power or heat for diffusion of the volatiles."
  • Proyecto final de Grado
    Desarrollo del modelo aerodinámico del Fórmula SAE 2012
    (2018) Scomazzon, Nicolás Andrés; Raffo, Federico; Zubiri, Juan Ignacio
    "El Fórmula SAE ITBA fue desarrollado y construido por alumnos de la Universidad a lo largo de los años. En las sucesivas etapas del proyecto se diseñaron los distintos componentes y sistemas del vehículo, pero nunca hasta el momento se había realizado un análisis aerodinámico. En base a ello, este trabajo busca mostrar cómo generar un modelo computacional que pueda ser utilizado para realizar el mencionado análisis y obtener conclusiones en cuanto a las cargas aerodinámicas y los distintos flujos de aire de interés que existen sobre el vehículo. Estos objetivos se buscarán cumplir mediante la implementación de un análisis Computational Fluid Dynamics (CFD)."
  • Tesis de maestría
    Evaluation of StarCCM+ to predict thermoacoustic instabilities using Large Eddy Simulation
    (2017) Indlekofer, Thomas; Ariatabar, Behdad; Bauer, Hans-Jörg; Hermeth, Sebastian
    "Self-sustained pressure and heat-release oscillations yielded by thermoacoustic coupling are a major problem of gas turbine operation and methods to predict them are needed. This work investigates the capabilities of Large Eddy Simulation (LES) in StarCCM+ to predict these instabilities in the academic Volvo bluff-body combustor. First, simplified cases are studied to assess boundary condition treatment and numerical accuracy of the methods available. The non-reactive operating point is predicted accurately, showing good agreement for velocity fields as well as the ability to predict the vortex shedding frequency in the intrinsically unsteady region of the recirculation zone. For a reacting-stable operating point the acceleration downstream of the bluff body is overpredicted and the flow fields are not predicted accurately. Low frequency oscillations of the unstable operating points are evidenced coincididing with experimental results and an acoustic analysis based on Comsol Multiphysics. Up to = 1:0 the coherence of the equivalence ratio and the magnitude of the instabilities is predicted qualitatively."
  • Tesis de maestría
    Experimental investigation of air entrainment by a vertical jet plunging into a liquid pool
    (2018) Büttner, Fabian; Schulenberg, Thomas; Gabriel, Stephan; Kuhn, Dietmar
    "The aim of the work is the investigation of the liquid flow field that is induced by the jet inside the receiving pool and the simultaneous observation of the gaseous phase. The applied meas-urement techniques were Particle Image Velocimetry (PIV) for analysing the liquid flow field and shadowgraph imaging, which enables a study of the dispersed air bubbles. Furthermore, all boundary conditions that influence the experiment were recorded."
  • Artículo de Publicación Periódica
    Influence of bottleneck lengths and position on simulated pedestrian egress
    (2017-01) Parisi, Daniel; Patterson, Germán
    "In this paper, the problem of pedestrian egress under di erent geometries is studied by means of two numerical models. The length of the bottleneck after the exit and the distance of the exit to the lateral wall of a squared room are investigated. Both models show that an increase in the bottleneck length increases the evacuation time by more than 20%, for any exit position. Hence, a bottleneck length tending to zero is the best choice. On the contrary, the results of moving the exit closer to the lateral wall are different in both models and, thus, its convenience cannot be stated. To unveil whether this layout modi cation is favorable, experimental data are required. Moreover, the discrepancy between models indicates that they should be validated considering several scenarios."
  • Artículo de Publicación Periódica
    Microfluidic device concept based on microoscillator dynamics at a liquid–liquid interface
    (2008) Allievi, Alejandro
    "Oscillating microbeams and microplates have been used extensively as sensing components for property detection in fluids. In liquids, their quality factor Q is drastically decreased, thus affecting a microsensor’s resolution. To improve the Q-factor, we present a novel concept based on the positive use of surface tension on a mechanical oscillator composed of a microbeam–microplate assembly suspended at a liquid–liquid interface in a microfluidic channel. An analytical model is developed to investigate rotational dynamics of such an assembly..."
  • Artículo de Publicación Periódica
    Rapid reconstitution packages (RRPs) for stable storage and delivery of glucagon
    (2019-06) D'hers, Sebastián; Abad Vázquez, Agustín; Gurman, Pablo; Elman, Noel M.
    "Current emergency injectors of glucagon require manual reconstitution, which involves several steps that may lead to dosage errors. Rapid reconstitution packages (RRPs) are new devices, designed using computational fluid dynamics (CFD) to optimize fluid mixing, integrating physical properties of active pharmaceutical ingredients (APIs), excipients and diluents. RRPs improve drug stability for long-term storage and ease of delivery. Device prototypes were manufactured using advanced stereolithography apparatus (SLA) 3D printing technology. Reconstitution of glucagon with RRPs was evaluated by highperformance liquid chromatography (HPLC) and optical spectroscopy methods. Enzyme-linked immunosorbent assays were performed to test in vitro activity. Experimental results showed that RRPs effectively reconstituted glucagon even after exposure to 60 °C for a 24-h period. RRPs exhibited improved performance at maintaining drug stability compared to lyophilized glucagon stored in a standard glass vial under the same temperature conditions. RRPs represent a portable platform for rapid reconstitution of lyophilized drugs, compatible with standard syringes available in any clinical setting. The RRP provides an alternative to manual reconstitution process, especially designed for medical emergencies."
  • Artículo de Publicación Periódica
    Simulating competitive egress of noncircular pedestrians
    (2017-04) Cruz Hidalgo, R.; Parisi, Daniel; Zuriguel, Iker
    "We present a numerical framework to simulate pedestrian dynamics in highly competitive conditions by means of a force-based model implemented with spherocylindrical particles instead of the traditional, symmetric disks. This modification of the individuals’ shape allows one to naturally reproduce recent experimental findings of room evacuations through narrow doors in situations where the contact pressure among the pedestrians was rather large. In particular, we obtain a power-law tail distribution of the time lapses between the passage of consecutive individuals. In addition, we show that this improvement leads to new features where the particles’ rotation acquires great significance."