Analysis of spray-wall impingement, fuel film spreading and vaporisation for reciprocating engine applications

The road transport is responsible of a considerable amount of pollutants emissions at the worldwide scale. To tackle this issue, many laws are trying to give a framework to reduce the emissions at the global scale. The law are always more restrictive, and they oriented the car manufacturers to the reduction of their gasoline engine size. This phenomenon, called downsizing, lead to the use of direct injection in order to improve the power/volume ratio of the engine. However, with direct injection the problem of particle emissions arose. Indeed, the liquid film generated during the injection process are responsible of inhomogeneities in the combustion chamber which lead to particles formation. In this context, the study of the fuel films in the combustion chamber is a major concern. To perform this study several experimental apparatus are designed in this thesis. A high-pressure 3-hole solenoid injector is used in order to generate liquid films. The generation and the spreading of the liquid films is observed and modelled. Then the thermal aspects of the spray impingement is studied, to characterise the local heat transfer. These thermal loss are delaying the evaporation of the liquid film, which will lead to inhomogeneities in the combustion chamber and particle generation. A modelling of the heat transfer is also proposed, finally the evaporation rate of alkanes films is proposed. Mono and multicomponents films are studied, these measures were used to calibrate a numerical model for the evaporation of thin liquid films on hot walls. Together with the previous experimental investigationsand models a test campaign on a real engine has been held. The objective is to confirm that, the results produced out of the engine are transposable to the engine (with careful attention). Conclusions on the different aspects are then presente

Spanish interpreters and the training, qualifications and requirements needed in order to work in the mental health domain

Tras varias conversaciones con profesionales de la salud mental, se hizo evidente la ausencia de intérpretes profesionales en el ámbito de la salud mental en España, acompañada de una falta de formación en salud mental, y de unas calificaciones y requisitos necesarios que no están especificados todavía en clínicas ni hospitales. La Teoría Fundamentada permite desarrollar una teoría que compensa las carencias de estudio sobre esta temática en España. Los resultados determinan que es necesaria una formación en salud mental para los intérpretes y que las clínicas y hospitales deben establecer unos requisitos mínimos para poder evitar el intrusismo laboral.After some discussions with mental health workers, it was clear to see the absence of interpreters in the mental health domain in Spain, followed by a lack of specific training, qualifications and requirements needed for interpreters in order to work in the field. Grounded Theory allows the development of a theory that offsets the lack of research in this topic in Spain. The results expose that the training in mental health, as well as some requisites to be able to work in clinics and hospitals as an interpreter, are essential, in order to avoid the unauthorised practice of the profession

A Genetic Algorithm to Schedule Workflow Collections on a SOA-Grid with Communication Costs

International audienceIn this paper we study the problem of scheduling a collection of workflows, identical or not, on a SOA grid. A workflow (job) is represented by a directed acyclic graph (DAG) with typed tasks. All of the grid hosts are able to process a set of task types with unrelated processing costs and are able to transmit files through communication links for which the communication times are not negligible. The goal is to minimize the maximum completion time (makespan) of the workflows. To solve this problem we propose a genetic approach. The contributions of this paper are both the design of a Genetic Algorithm taking the communication costs into account and the performance analysis

Comparison on OpenStack and OpenNebula performance to improve multi-Cloud architecture on cosmological simulation use case

With the increasing numbers of Cloud Service Providers and the migration of the Grids to the Cloud paradigm, it is necessary to be able to leverage these new resources. Moreover, a large class of High Performance Computing (HPC) applications can run these resources without (or with minor) modifications. But using these resources come with the cost of being able to interact with these new resource providers. In this paper we introduce the design of a HPC middleware that is able to use resources coming from an environment that compose of multiple Clouds as well as classical \hpc resources. Using the \diet middleware, we are able to deploy a large-scale, distributed HPC platform that spans across a large pool of resources aggregated from different providers. Furthermore, we hide to the end users the difficulty and complexity of selecting and using these new resources even when new Cloud Service Providers are added to the pool. Finally, we validate the architecture concept through cosmological simulation RAMSES. Thus we give a comparison of 2 well-known Cloud Computing Software: OpenStack and OpenNebula.Avec l'augmentation du nombre de fournisseurs de service Cloud et la migration des applications depuis les grilles de calcul vers le Cloud, il est nécessaire de pouvoir tirer parti de ces nouvelles ressources. De plus, une large classe des applications de calcul haute performance peuvent s'exécuter sur ces ressources sans modifications (ou avec des modifications mineures). Mais utiliser ces ressources vient avec le coût d'être capable d'intéragir avec des nouveaux fournisseurs de ressources. Dans ce papier, nous introduisons la conception d'un nouveau intergiciel HPC qui permet d'utiliser les ressources qui proviennent d'un environement composé de plusieurs Clouds comme des ressources classiques. En utilisant l'intergiciel \diet, nous sommes capable de déployer une plateforme HPC distribuée et large échelle qui s'étend sur un large ensemble de ressources aggrégées entre plusieurs fournisseurs Cloud. De plus, nous cachons à l'utilisateur final la difficulté et la complexité de sélectionner et d'utiliser ces nouvelles ressources quand un nouveau fournisseur de service Cloud est ajouté dans l'ensemble. Finalement, nous validons notre concept d'architecture via une application de simulation cosmologique RAMSES. Et nous fournissons une comparaison entre 2 intergiciels de Cloud: OpenStack et OpenNebula

Approaching the quantitative description of enantioselective adsorption by the density functional theory means

The applications of enantiopure organic compounds range from medicine to green agrochemistry. Their racemic or enantioselective synthesis permits their acquisition beyond the extraction from life forms. These procedures need chiral resolution steps to achieve the required degrees of enantiomeric purity, though. Many research endeavours are addressed at finding chiral materials able to separate the enantiomers by their selective adsorption upon. Transition metal chiral surfaces have been found to reach enantiomeric excess degrees of purity outperforming surfaces of naturally existing chiral materials. Future research can be driven by high-throughput computational screening, given the employed methodology is able to discern the subtle enantiomeric differences of free energies of adsorption. The capabilities of density functional theory methods are here evaluated on the textbook case of D/L-aspartic acid adsorption on chiral Cu(3,1,17)R&S metal surfaces. Results show that dispersive forces are a prerequisite to properly describe the enantioselective adsorption, whereas the inclusion of fundamental vibrational energy and adsorbate vibrational free energies are key ingredients to approach a quantitative description. Simulated X-ray photoemission and infrared spectra indicate that the adsorption conformations can be qualitatively recognized

Spreading model for wall films generated by high-pressure sprays

[EN] This paper presents a new model developed to predict the area of wall films that may develop in gasoline direct injection engines (GDI). In a always more restrictive legislation on gas emissions the injection process in internal combustion (IC) engines has been highlighted as a domain of great concern in order to satisfy these requirements. Many spray wall interactions models exist in literature and are included in different CFD tools. Most often they are based on the sum of single drop-wall impacts. The specificity of the present model lies in its simplicity and the way the film is treated globally. Here its propagation is predicted using a balance between the momentum given by the spray and the viscous shear stress. Jointly with the theoretical model, an experimental set-up has been built up, an optical measurement technique called Refractive Index Matching method is used to follow the development of the wall film. It has been found that the area of the wall film is proportional to the duration of injection, while the distance between the injector and the wall has not shown many influence on the evolution of area. The influence of the injection pressure has also been identified, when the pressure is doubled the radius of the film is multiplied by √3 2. Eventually the model predicts that film thickness decreases as fuel pressure rises.ANR and ANRT are acknowledged for their financial support.Lamiel, Q.; Lamarque, N.; Hélie, J.; Legendre, D. (2017). Spreading model for wall films generated by high-pressure sprays. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 138-145. https://doi.org/10.4995/ILASS2017.2017.4999OCS13814

Fan-C, a Frama-C plug-in for data flow verification

International audienceDO-178B compliant avionics development processes must both define the data and control flows of embedded software at design level, and verify flows are faithfully implemented in the source code. This verification is traditionally performed during dedicated code reviews, but such intellectual activities are costly and error-prone, especially for large and complex software. In this paper, we present the Fan-C plug-in, developed by Airbus on top of the abstract-interpretation-based value and dataflow analyses of the Frama-C platform, in order to automate this verification activity for C avionics software. We therefore describe the Airbus context, the Frama-C platform, its value analysis and related plug-ins, the Fan-C plug-in, and discuss analysis results and ongoing industrial deployment and qualification activities

Can one hear the shape of a drum?

Treballs Finals de Grau de Matemàtiques, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2023, Director: Francesc Xavier Massaneda Clares i Joaquim Ortega Cerdà[en] In this work we study Mark Kac’s classical problem “Can one hear the shape of a drum?” and some of its extensions. They are all inverse problems on characterizing the shape, or at least some geometrical information about the shape, of an Euclidean domain from its Dirichlet spectrum. As to the original problem, we answer it negatively by providing an example of two different shaped planar drums that have the same spectrum of frequencies. As to the extensions, we prove that the spectrum of frequencies of a planar drum characterizes its area. These results are straightforwardly generalized to higher dimensions. Finally, we comment variants of Kac’s problem for which there are positive results for the characterization of the shape of a drum from its spectrum

Millores aerodinàmiques d'un SEAT 132

Aquest projecte consisteix en l'estudi dels diferents elements i dispositius aerodinàmics que hauria d'incloure un vehicle de competició. Tots són importants i tenen una funció crucial dins l'aerodinàmica d'un vehicle de competició segons les condicions del circuit on competirà. Un cop realitzat l'estudi es proposarà un disseny d'algun d'aquests elements que existeixen