Acoustic characterization of the compressor stage of an automotive turbocharger

Turbochargers are a key component of internal combustion engines in the automotive industry. They contribute to the downsizing trend and allow constructors to respect more and more severe emissions norms. However, the turbocharger behaves as an acoustic source in the air intake system, and has an influence in the acoustic waves travelling in it. The passive and active acoustic characteristics of the turbocharger can be used as a starting point for the design and development of acoustic devices in the air intake system, or as an input of acoustic 1D simulations of engine intake lines. In this paper both the active and passive acoustic behaviours of a compressor stage of two different automotive turbochargers were studied. The active acoustic effect of the compressor was studied by its characterization as an acoustic source. This is performed experimentally by the computation of the acoustic power at the inlet and outlet of the compressor. This power was obtained by performing plane wave decomposition with the beamforming method over all the working points of the compressor map. Using the pressure decomposition, the acoustic intensity is calculated and then the acoustic power. In this way the acoustic power delivered by the compressor on the air intake system is measured. The passive acoustic effect is studied by the measurement of the acoustic Transmission Loss (TL) of the compressor through the calculation of its scattering matrix under two port considerations. Using also the beamforming method to decompose the incident and reflected waves at the inlet and outlet of the compressor, the transmission coefficients in both upwards and downwards directions are computed. Experimentally the TL of a static turbocharger was measured and results were extrapolated by a model to obtain the TL of the compressor over different working points of the compressor map. Numerically, 3D acoustic simulations were performed in order to compare to the model results. Numerical and experimental results were compared, and a predictive model for TL is proposed. This model will be compared in the future to real TL measurements on a working turbocharger

ZONAS DE INUNDACIÓN QUEBRADA ZIPACHA, PAMPLONA MEDIANTE SOFTWARE HEC RAS

La modelación de fenómenos hidráulicos e hidrológicos es importante en diferentes regiones del mundo, y sobre todo en los cuerpos hídricos cercanos a zonas pobladas, generando la necesidad de estudiar el comportamiento de dichos cuerpos de agua, con el fin de implementar mecanismos base, que a futuro harán parte de los sistemas de alertas tempranas, y evitar la afectación de los habitantes cercanos. Debido a esto se implementó el software HEC_RAS versión 4.1.0 para modelar las zonas de inundación de la Q. Zipacha, donde levantaron 167 secciones transversales, y utilizaron los coeficientes de Manning, según las condiciones del área y caudales máximos de 1,05 m3/s, 0,83 m3/s y 0,69 m3/s a diferentes periodos de retorno 2, 5 y 10 años respectivamente, dando como resultado zonas inundables con poca consideración grave, presentes en la parte alta-media de la microcuenca Zipacha, esto se debe a las alta presencia de especies vegetales alrededor de dichas secciones, pequeña área de la sección transversal, generando acumulación de agua. En conclusión, los resultados no reflejan un riesgo para la zona de estudio ni para la población que habita en ella, siendo necesaria la vigilancia de estas zonas para evaluar su evolución y no permitir la acumulación de sedimentos de arrastre e incremento del volumen de las zonas inundables en esas zonas

Estrategias que impulsan el crecimiento sostenible de una empresa de autopartes

Después de aplicar una estrategia agresiva durante los últimos cuatro años con muy buenos resultados, las ventas de la empresa de autopartes, objeto de estudio de este trabajo, empezaron a desacelerarse. En el mercado, el valor de sus acciones no muestra un mayor repunte, la rentabilidad sobre la inversión representa el 12 % (muy por debajo del mercado) y la empresa aún no es considerada como un socio estratégico clave para los fabricantes de autos de lujo. Este negocio consiste en la fabricación de arneses y cableado para fabricantes de autos de lujo, localizados principalmente en Estados Unidos. Su propuesta de valor se basa en ofrecer productos innovadores con diseño personalizado para satisfacer las necesidades de los clientes, apostando por la innovación, la investigación y el desarrollo

O final dos reinos: Diálogos entre Tiwanaku e La Aguada

Este escrito pone de nuevo a dialogar las iconografías de Tiwanaku (altiplano del Titicaca, Bolivia) y La Aguada (Noroeste de la Argentina), a más de 40 años de los trabajos de Rex González y de Ponce Sanginés. Lo hace en un contexto enteramente diferente con un énfasis decolonial. Objetos, imágenes, información etnográfica y arqueólogos de ambos lados de una frontera entre "naciones", se ensamblan con la clara intención de cuestionar supuestos subyacentes muy profundos de la arqueología. Metodología: a partir de los caminos que plantean las imágenes y colores, se amarran en estos nudos también los humanos y las cosas, las experiencias chamánicas y los fenómenos meteorológicos, todos enlazados de modo relacional. Conclusiones: tras poner a dialogar a La Aguada y Tiwanaku, con base en nuestras trayectorias investigativas, la discusión desemboca en una reflexión acerca de las consecuencias presentes de naturalizar miradas segmentadas y funcionalistas de los mundos animales y vegetales en el pasado, que se originan en los subyacentes ontológicos de nuestra propia modernidad. Originalidad: el texto apunta a abordar la crítica decolonial a partir del estudio de casos concretos y a aportar a esos debates desde materialidades arqueológicas.This paper once again brings the iconographies of Tiwanaku (Titicaca high plateau, Bolivia) and La Aguada (Northwest of Argentina) into discussion, more than 40 years after the works of Rex González and Ponce Sanginés. It does so in an entirely different context with a decolonial emphasis. Objects, images, ethnographic information and archaeologists from both sides of a border between “nations” are assembled with the clear intention of questioning very deep underlying assumptions of archaeology. Methodology: Beginning with the paths posed by images and colors, these knots also bind humans and things, shamanic experiences and meteorological phenomena. Conclusions: After bringing La Aguada and Tiwanaku into dialogue, based on our research trajectories, the discussion leads to a reflection on the present consequences of naturalizing segmented and functionalist gazes of the animal and plant worlds in the past, which originate in the ontological underpinnings of our own modernity. Originality: The text aims to approach decolonial criticism from the study of concrete cases and to contribute to these debates on the basis of archaeological materiality.Fil: Marconetto, María Bernarda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Antropología de Córdoba. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Instituto de Antropología de Córdoba; ArgentinaFil: Villanueva Criales, Juan Eduardo. Museo Nacional de Etnografía y Folklore; Bolivi

Contribution à la modélisation d’un turbocompresseur automobile et sa caractérisation acoustique

In this thesis, methodologies to perform the acoustic passive and active characterization of two port systems are presented. These methods are based on plane wave decomposition made at the inlet and at the outlet of the system. This decomposition is made according beamforming technique. Once these methods were validated on simple geometries, they were then applied to the compressor stage of an automotive turbocharger. The active acoustic characterization is made by the measurement of the acoustic power and acoustic intensity in the compressor ducts on given working points, but also on complete compressor maps. This was performed on turbocharger benches, engine benches and a complete vehicle. The passive acoustic characterization is made by the calculation of characteristic matrices (transfer matrix, impedance matrix and scattering matrix). These matrices are then used to compute the acoustic transmission loss. Experiments were performed on a static turbocharger and compared to 3D finite elements simulations, as well as experiments on an operating turbocharger.Dans cette thèse, des méthodes de caractérisation acoustique passive et active de systèmes acoustiques à deux ports sont présentées, basées sur une décomposition d’ondes planes en entrée et sortie. Cette décomposition est réalisée par la méthode du beamforming. Ces méthodes mises en place et validées sur des géométries simples, sont ensuite employées pour caractériser l’étage compresseur d’un turbocompresseur de suralimentation automobile. La caractérisation acoustique active se fait par la mesure de la puissance et de l’intensité acoustique dans les conduits du compresseur, ceci pour des points de fonctionnement spécifiques, des cartographies compresseur complètes sont également élaborées. Les essais ont été menés sur banc turbo, banc moteur et sur véhicule complet. La caractérisation acoustique passive est abordée par le calcul de matrices du compresseur (matrice de transfert, matrice d’impédance et matrice de diffusion). Le calcul de la perte par transmission acoustique est déduit de ces matrices. Des essais ont été réalisés et comparés à des simulations éléments finis 3D sur un turbocompresseur statique comme sur un turbocompresseur opérationnel

Contribution to the modeling of an automotive turbocharger and its acoustic characterizations

Dans cette thèse, des méthodes de caractérisation acoustique passive et active de systèmes acoustiques à deux ports sont présentées, basées sur une décomposition d’ondes planes en entrée et sortie. Cette décomposition est réalisée par la méthode du beamforming. Ces méthodes mises en place et validées sur des géométries simples, sont ensuite employées pour caractériser l’étage compresseur d’un turbocompresseur de suralimentation automobile. La caractérisation acoustique active se fait par la mesure de la puissance et de l’intensité acoustique dans les conduits du compresseur, ceci pour des points de fonctionnement spécifiques, des cartographies compresseur complètes sont également élaborées. Les essais ont été menés sur banc turbo, banc moteur et sur véhicule complet. La caractérisation acoustique passive est abordée par le calcul de matrices du compresseur (matrice de transfert, matrice d’impédance et matrice de diffusion). Le calcul de la perte par transmission acoustique est déduit de ces matrices. Des essais ont été réalisés et comparés à des simulations éléments finis 3D sur un turbocompresseur statique comme sur un turbocompresseur opérationnel.In this thesis, methodologies to perform the acoustic passive and active characterization of two port systems are presented. These methods are based on plane wave decomposition made at the inlet and at the outlet of the system. This decomposition is made according beamforming technique. Once these methods were validated on simple geometries, they were then applied to the compressor stage of an automotive turbocharger. The active acoustic characterization is made by the measurement of the acoustic power and acoustic intensity in the compressor ducts on given working points, but also on complete compressor maps. This was performed on turbocharger benches, engine benches and a complete vehicle. The passive acoustic characterization is made by the calculation of characteristic matrices (transfer matrix, impedance matrix and scattering matrix). These matrices are then used to compute the acoustic transmission loss. Experiments were performed on a static turbocharger and compared to 3D finite elements simulations, as well as experiments on an operating turbocharger

The Transcriptomic Toolbox: Resources for Interpreting Large Gene Expression Data within a Precision Medicine Context for Metabolic Disease Atherosclerosis

As one of the most widespread metabolic diseases, atherosclerosis affects nearly everyone as they age; arteries gradually narrow from plaque accumulation over time reducing oxygenated blood flow to central and periphery causing heart disease, stroke, kidney problems, and even pulmonary disease. Personalized medicine promises to bring treatments based on individual genome sequencing that precisely target the molecular pathways underlying atherosclerosis and its symptoms, but to date only a few genotypes have been identified. A promising alternative to this genetic approach is the identification of pathways altered in atherosclerosis by transcriptome analysis of atherosclerotic tissues to target specific aspects of disease. Transcriptomics is a potentially useful tool for both diagnostics and discovery science, exposing novel cellular and molecular mechanisms in clinical and translational models, and depending on experimental design to identify and test novel therapeutics. The cost and time required for transcriptome analysis has been greatly reduced by the development of next generation sequencing. The goal of this resource article is to provide background and a guide to appropriate technologies and downstream analyses in transcriptomics experiments generating ever-increasing amounts of gene expression data

Seismic Risk of Weak First-Story RC Structures with Inerter Dampers Subjected to Narrow-Band Seismic Excitations

This study evaluates the seismic risk of weak first-story reinforced concrete (RC) structures retrofitted with inerter dampers at their ground level when subjected to narrow-band seismic excitations. The main advantages brought about by the ground-level inerters are the reductions in seismic demands (e.g., drifts, floor accelerations). This study shows that structures with inerters are reliable systems in terms of peak story drifts for large ground motions. For moderate ground-motion intensities, the opposite could occur, mainly for soft soil sites. The reliabilities of structures with inerter dampers at their ground level are in general higher for buildings under seismic intensities associated to limit state of incipient collapse, especially for low-height buildings. This could be reversed for intensities associated to the limit state of damage limitation. The findings of this study could guide practicing engineers to use inerter-based dampers in retrofitting ductile structures consisting of moment-resisting reinforced concrete (RC) frames subjected to narrow-band earthquake excitations in regions such as Mexico City

Tectonic DSAEK for the Management of Impending Corneal Perforation

Purpose. To report a case of severe corneal thinning secondary to dry eye treated with a tectonic Descemet stripping automated lamellar keratoplasty (DSAEK) and amniotic membrane graft. Methods. A 72-year-old man with a history of long standing diabetes mellitus type 2 and dry eye presented with 80% corneal thinning and edema on the right eye and no signs of infectious disease, initially managed with topical unpreserved lubrication and 20% autologous serum drops. Eight weeks after, the defect advanced in size and depth until Descemetocele was formed. Thereafter, he underwent DSAEK for tectonic purposes. One month after the procedure, the posterior lamellar graft was well adhered but a 4 mm epithelial defect was still present. A multilayered amniotic membrane graft was then performed. Results. Ocular surface healed quickly and reepithelization occurred over a 2-week period. Eight months after, the ocular surface remained stable and structurally adequate. Conclusion. Tectonic DSAEK in conjunction with multilayered amniotic graft may not only provide structural support and avoid corneal perforation, but may also promote reepithelization and ocular surface healing and decrease concomitant inflammation