À l'ère de la mondialisation, les entreprises opèrent dans un marché de plus en plus concurrentiel. Les entreprises cherchent à offrir un produit ou un service de performance élevée afin de faire face à la compétition. Quels sont donc les facteurs clés de succès qui assurent une meilleure performance du produit? L'objectif de la présente recherche est d'identifier les facteurs clés de succès qui influencent la performance d'un produit dans un contexte de collaboration touristique réussie. Une revue de la littérature a permis de dresser une liste des facteurs clés qui influencent la réussite des projets. Ces facteurs, transférés à un contexte de performance de produit, ont été regroupés en trois dimensions: « les facteurs liés aux relations », « les facteurs liés à l'environnement» et « les facteurs liés au produit et service ». Cette dernière dimension se compose de trois construits: la nouveauté du produit, le financement ainsi que la planification et l'objectif du projet. Afin de pouvoir répondre aux objectifs de la recherche, une enquête par questionnaire web a été réalisée auprès des organisations opérant dans le secteur touristique et appartenant au secteur public et privé. L'étude repose sur 256 questionnaires. Les analyses des données ont fait ressortir que les facteurs liés aux relations, les facteurs liés à l'environnement ainsi que la planification et l'objectif du projet sont ceux qui influencent le plus la performance du produit réalisé dans le cadre de projets de collaboration touristique. Dans le cadre de cette recherche, le financement ne s'est pas avéré un facteur d'influence pour la performance du produit touristique. Cette étude a permis de valider certains facteurs clés de succès dans un contexte de collaboration touristique. Elle permet ainsi aux responsables des projets de collaboration dans le secteur touristique de se focaliser sur les facteurs qui assurent une meilleure performance du produit final réalisé dans un contexte de projet de collaboration réussie. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Facteurs clés du succès, Performance du produit, Collaboration, Tourisme.

Les Chambres de bois met en scène les personnages de Lia, Catherine et Michel qui rappellent respectivement les figures mythiques de Lilith, d'Ève et de Narcisse. Dans ce récit d'Anne Hébert, la genèse semble réécrite alors que Catherine pénètre dans l'univers des chambres de bois, paradis perdu de Michel et Lia, où elle tente de trouver sa place entre ce frère et cette sœur qui cherchent à racheter la faute originelle. Sa survie réside dans la fuite hors de ce monde édénique, et ce mémoire explore les motifs qui justifient ce départ tant sur le plan des personnages que sur celui de la constitution du récit. Chaque chapitre définit un des trois protagonistes hébertiens pour saisir comment il se pose dans le récit et dans les différents univers que celui-ci met en place. Ces considérations amènent une première réponse à l'inévitable départ de Catherine : l'héroïne s'établit à travers la concrétude de la réalité et ne peut cohabiter avec Lia et Michel qui incarnent le rêve et l'absence de réalité. Cette impossibilité à partager le même espace se déploie aussi à travers la constitution des personnages. Alors que la deuxième section du mémoire démontre que Catherine répond aux exigences du personnage mimétique et romanesque; le premier et le troisième chapitres voient comment, en s'y soustrayant, Michel et Lia se définissent plutôt comme personnages poétiques et non romanesques. Cette distinction fondamentale permet non seulement d'associer chacun des protagonistes à une figure mythique et d'ainsi lire le récit hébertien comme une genèse réécrite et réactualisée, mais aussi d'expliquer la fuite nécessaire de Catherine hors des chambres de bois. Ce faisant, ce mémoire explique pourquoi il convient de lire ce texte d'Anne Hébert non pas comme roman mais comme récit poétique, et de conclure que la signification profonde de celui-ci se trouve dans l'exploration de l'intertexte biblique et mythique. ______________________________________________________________________________

El estudio de la medida de la salinidad del océano junto con la humedad del terreno constituyen dos de las aplicaciones más importantes dentro del mundo de la teledetección que no han sido estudiadas hasta la fecha. Concretamente esta tesis se va a centrar en la primera de ellas. La concentración salina de los océanos está ligada al clima y, en consecuencia su conocimiento a nivel global en cada instante puede representar un buen índice de referencia a la hora de realizar las predicciones climáticas, ya que es un indicador de las corrientes marinas, y de la diferencia entre evaporación y precipitación. En el mes de mayo de 1999 la Agencia Espacial Europea (ESA) seleccionó la misión SMOS (Soil Moisture and Ocean Salinity) con el fin de realizar estudios en ambos campos, utilizando un radiómetro de apertura sintética bidimensional en banda L (MIRAS; Microwave Imagin Radiometer by Aperture Synthesis) instalado en un satélite que se prevé será puesto en órbita a principios del año 2007.Con objeto de mejorar los modelos de emisión del mar en banda L y de estudiar la recuperación de la salinidad mediante medidas radiométricas multiangulares, la ESA aprobó el experimento WISE (WInd and Salinity Experiment) que se realizó a lo largo de dos campañas, durante los últimos meses de los años 2000 y 2001 en la plataforma petrolífera Casablanca, situada 50 Km mar adentro frente a las costas de Tarragona. En dichas campañas participaron cinco grupos de científicos de diferentes países (España, Francia y Estados Unidos).La finalidad de los experimentos fue el estudio de la temperatura de brillo del mar teniendo en cuenta la influencia de su estado provocado por el viento, la espuma, el mar de fondo, etc. Para ello se utilizó un radiómetro de apertura real tipo Dicke completamente polarimétrico, diseñado y construido en la UPC (Universitat Politècnica de Catalunya) a tal efecto.La tercera campaña, FROG (Foam, Rain, Oil slicks and GPS reflectometry) fue patrocinada por el Ministerio de Ciencia y Tecnología y se realizó durante la primavera del año 2003, junto a la desembocadura del Río Ebro. Ésta consistió en determinar la contribución en la variación de la temperatura de brillo debida a algunos de los efectos ya mencionados tales como: la espuma, la lluvia y las manchas de aceite. Las medidas de la temperatura de brillo se realizaron variando la concentración salina a voluntad, desde 0 psu hasta 38 psu y, estudiando separadamente cada uno de estos efectos.

Computational fluid dynamics (CFD) has been widely applied to simulate turbulent flows in an urban environment. The two basic methodologies in CFD that have been applied here are a Reynolds-averaged Navier-Stokes (RANS) modeling and a large-eddy simulation (LES). The nature of the flow in a built-up urban area consisting of an arbitrary aggregation of buildings is dominated by unsteady large-scale turbulent structures. Recognizing that RANS is unable to correctly capture these turbulent structures while LES is associated with high computational costs, a hybrid RANS/LES methodology that combines the computational efficiency of RANS with the predictive accuracy of LES can be a promising simulation approach for the application to urban flows. In the non-zonal approach of hybrid RANS/LES methodology, a single generalized turbulence model is used in the entire computational domain. This model can function as a RANS turbulence closure model or as a LES subgrid scale model, depending on the local grid resolution or flow properties. A variant of non-zonal approaches, referred as partially resolved numerical simulation (PRNS) in this study, obtains the generalized turbulence model from the rescaling of a conventional RANS model through the incorporation of a resolution control function (F_R). The resolution control function F_R is used to characterize the degree of modeling required to represent the unresolved scales of motion. A new generalized functional form for F_R in PRNS is proposed in this thesis. The predictive performance of PRNS is compared with unsteady RANS (URANS) and LES computations, for a plane channel flow, and for fully-developed and developing flows over a matrix of cubes resembling a group of buildings. It is demonstrated that PRNS behaves similarly to LES, in terms of the predictions of the mean flow and turbulence, but outperforms URANS in general. This indicates PRNS is a promising approach for the simulation of complex turbulent flows in an urban environment.

This thesis has been a part of Forsmarks Kraftgrupp AB's evaluation of a turbulence model used in simulation of turbulent flow called PRNS (Partially Resolved Numerical Simulation). This model has promising properties and may be of use in saving computational resources. The purpose of this thesis was to analyze this model and compare it with industrially applied models such as k-omega SST and LES (Large Eddy Simulations). PRNS works as a hybrid of the k-omega SST and DNS (Direct Numerical Simulation) where a constant, RCP (Resolution Control Parameter) with a value between 0 and 1 are selected. This constant is then used in the calculations and determines the behavior of the simulation. When RCP is set to zero the equation are the same as for a DNS simulation and when RCP is set to one the equations for k-omega SST is solved. In this report four different PRNS models have been used, three where RCP was given a constant value (0.1, 0.4 and 0.6). In the fourth model RCP is calculated from the flow field variables The models have been compared to an experiment from 2008 and simulations have been made to resemble the experiment. In the experiment a Particle Image Velocimeter (PIV) was used as method of measurement. From the experimental report data such as velocity (U), turbulent kinetic energy (k) and standard deviation (URMS) have been obtained and have formed the basis for comparison. The models have been simulated in two different software programs: OpenFOAM and Fluent. The data have thereafter been post processed in the software programs MatLab and ParaView, to be compared with experimental data. The results of the simulations have shown that PRNS models generally show a good accordance with experimental data. In particular, PRNS models with constant RCP have shown good results, however, there are some discrepancies. The PRNS model with varying RCP has in most cases showed the largest deviation from experimental data but also a deviation from the other models, including the reference models. Due to the design of the mesh (coarse) further evaluation of the PRNS models will be needed. First, simulate with a finer mesh, but also more complex geometries should be simulated in order to sort out PRNS strengths and weaknesses and thus determine if the model can be used in the daily work at Forsmarks Kraftgrupp AB.

Computational fluid dynamics (CFD) has been widely applied to simulate turbulent flows in an urban environment. The two basic methodologies in CFD that have been applied here are a Reynolds-averaged Navier-Stokes (RANS) modeling and a large-eddy simulation (LES). The nature of the flow in a built-up urban area consisting of an arbitrary aggregation of buildings is dominated by unsteady large-scale turbulent structures. Recognizing that RANS is unable to correctly capture these turbulent structures while LES is associated with high computational costs, a hybrid RANS/LES methodology that combines the computational efficiency of RANS with the predictive accuracy of LES can be a promising simulation approach for the application to urban flows. In the non-zonal approach of hybrid RANS/LES methodology, a single generalized turbulence model is used in the entire computational domain. This model can function as a RANS turbulence closure model or as a LES subgrid scale model, depending on the local grid resolution or flow properties. A variant of non-zonal approaches, referred as partially resolved numerical simulation (PRNS) in this study, obtains the generalized turbulence model from the rescaling of a conventional RANS model through the incorporation of a resolution control function (F_R). The resolution control function F_R is used to characterize the degree of modeling required to represent the unresolved scales of motion. A new generalized functional form for F_R in PRNS is proposed in this thesis. The predictive performance of PRNS is compared with unsteady RANS (URANS) and LES computations, for a plane channel flow, and for fully-developed and developing flows over a matrix of cubes resembling a group of buildings. It is demonstrated that PRNS behaves similarly to LES, in terms of the predictions of the mean flow and turbulence, but outperforms URANS in general. This indicates PRNS is a promising approach for the simulation of complex turbulent flows in an urban environment.

The prediction of transient phenomena inside Liquid Rocket Engines (LREs) has not been feasible until now because of the many challenges posed by the operating conditions inside the combustion chamber. Especially, the departure from ideal gas because of the cryogenic injection in a high-pressure chamber is one of the ma jor hurdle for such simula- tions. In order to begin addressing these issue, a real-gas model has been implemented in a massively parallel flow solver. This solver is capable of performing Large-Eddy Simula- tions (LES) in geometrical configurations ranging from an axisymmetric slice to a 3D slice up to a full 3D combustor. We present here the results from an investigation of unsteady combustion inside a small-scale, multi-injectors LRE. Both thermally perfect gas (TPG) and real gas (RG) approaches are evaluated for this LOX-GH2 system. The Peng-Robinson cubic equation of state (PR EoS) is used to account for real gas effects associated with the injection of cryogenic oxygen. Realistic transport properties are computed but simplified chemistry is used in order to achieve a reasonable turnaround time. Results show the impor- tance of the unsteady dynamics of the flow, especially the interaction between the different injectors. The role of the equation of state is assessed and the real gas model, despite a limited zone of application, seems to have a strong influence on the overall chamber behav- ior. Although several features in the simulated results agree well with past experimental observations, the prediction of heat flux using a simplified flux boundary condition is not completely satisfactory. This work also reviews in details the state of our knowledge on supercritical combustion in a coaxial injector configuration, stressing issues where numeri- cal modeling could provide new insights. However, many developments and improvements are required before an LES modeling of such a flow is both feasible and valid. We finally propose a comprehensive roadmap towards the completion of this goal and the possible use of CFD as a design tool for a modern liquid rocket engine.

The work presented in this dissertation concerns continued development, validation and verification of the partially averaged Navier-Stokes (PANS) method - a variable resolution closure model for turbulence. Linear eddy viscosity models (LEVM), which are popular because of their simplicity and affordability in terms of computational cost have fundamental deficiencies and cannot be trusted to accurately represent turbulence in realistic complex flows. The more high fidelity approaches such as large eddy simulations (LES) and direct numerical simulations (DNS) are out of realm of engineering applicability because of their high requirements in computing power. PANS, a variable resolution approach considered in this study, lies between LEVM and LES in terms of computational cost and is designed to prudently utilize the available computing power to improve accuracy. This dissertation presents the various studies performed to characterize the PANS fluctuations and extend the model for use in various wall bounded flows. The road map towards our goal includes: (i) Comparing a-priori and a-posteriori eddy viscosity values to establish whether PANS is capable of producing the pre-specified level of reduction. (ii) Investigating the scaling of PANS fluctuations for different levels of prescribed resolution and establishing if the fluctuations abide by known turbulence scaling laws. (iii) Extending PANS to k-w formulation which is better suited for wall-bounded shear flows, and (iv) Modifying the present LEVM to yield reasonable behavior in the rapid distortion limit where the turbulence is elastic in nature which ultimately affects PANS performance. Results reported in this dissertation illustrate that the PANS closure yields reliable and predictable reduction in the modeled viscosity. The accuracy of the simulations improve as the effective damping is reduced by lowering the specified viscosity providing credibility to the PANS method as a bridging model that performs as intended.

Gas turbine engines are the main propulsion source for world wide aviation and are also used for power generation. Even though they rely mainly on fossil fuel and emit climate active gasses, their importance is not likely to decrease in the future. But more efficient ways of using finite resources and hence reducing emissions have to be found. Thus, the interest to improve engine efficiency is growing. Considering the efficiency of the underlying thermodynamic cycle, an increase can be achieved by raising the turbine inlet temperature or compression ratio. Due to the complex nature of the underlying flow physics, however, the aero-thermal processes are still not fully understood. For this reason, one needs to perform research at high spatial and temporal resolution, in turn creating the need for effective means of postprocessing the large amounts of data. This dissertation addresses both sides of the problem - using high-scale, high resolution simulations as well as effective post processing techniques. As an example for the latter, a temporal highly resolved data set from wall pressure measurements of a transonic compressor stage is analyzed using proper orthogonal decomposition. The underlying experiments were performed by collaborators at Technical University Darmstadt. To decompose signals into optimal orthogonal basis functions based on temporal correlations including temperature, a formal mathematical framework is developed. A method to rank the reduced order representations with respect to heat transfer effectiveness is presented. To test both methods, a Reynolds-averaged Navier-Stokes (RANS) simulation and large eddy simulation (LES) are performed on turbulent heat transfer in a square duct with one single row of pin fins. While the LES results show closer agreement to experiments, both simulations unveil flow parts that do not contribute to heat transfer augmentation and can be considered wasteful. From the most effective mode, a wall contour for the same domain is derived and applied. In the wall contoured domain, energy in wasteful modes decreased, heat transfer increased and the temperature fluctuations at the wall decreased. Another stagnating boundary layer flow is examined in a direct numerical simulation of a first stage stator vane. Elevated levels of free stream turbulence and integral length scale are generated to simulate the features of combustor exit flow. The horseshoe vortex dynamics cause an increase in endwall heat transfer upstream of the vane. The link between energy optimal orthogonal basis functions and flow structures is examined using this data and the reduced order heat transfer analysis shows high energy modes with comparatively low impact on turbulent heat transfer. The analysis further shows that there are multiple horseshoe vortices that oscillate upstream of the blade, vanish, regenerate and can also merge. There is a punctual correlation of intense vortex dynamics and peaks in the orthogonal temperature basis function. For all data considered, the link between the energy optimal orthogonal basis functions and flow structures is neither guaranteed to exist nor straightforward to establish. The orthogonal expansion locks onto flow parts with high fluctuating kinetic energy - which might or might not be the ones that are looked for. The heat transfer ranking eliminates this problem and is valid independently of how certain basis functions are interpreted.

Numerical simulations were performed to study the turbulent mixing of a scalar species in straight tube, single and double elbow flow configurations. Different Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) models were used to model the turbulence in the flow. Conventional and dynamic Smagorinsky sub-grid scale models were used for the LES simulations. Wall functions were used to resolve the near wall boundary layer. These simulations were run with both two-dimensional and three-dimensional geometries. The velocity and tracer gas concentration Coefficient of Variations were compared with experimental results. The results from the LES simulations compared better with experimental results than the results from the RANS simulations. The level of mixing downstream of a S-shaped double elbow was higher than either the single elbow or the U-shaped double elbow due to the presence of counter rotating vortices. Penetration of neutralized and non-neutralized aerosol particles through three different types of tubing was studied. The tubing used included standard PVC pipes, aluminum conduit and flexible vacuum hose. Penetration through the aluminum conduit was unaffected by the presence or absence of charge neutralization, whereas particle penetrations through the PVC pipe and the flexible hosing were affected by the amount of particle charge. The electric field in a space enclosed by a solid conductor is zero. Therefore charged particles within the conducting aluminum conduit do not experience any force due to ambient electric fields, whereas the charged particles within the non-conducting PVC pipe and flexible hose experience forces due to the ambient electric fields. This increases the deposition of charged particles compared to neutralized particles within the 1.5” PVC tube and 1.5” flexible hose. Deposition 2001a (McFarland et al. 2001) software was used to predict the penetration through transport lines. The prediction from the software compared well with experiments for all cases except when charged particles were transported through non-conducting materials. A Stairmand cyclone was designed for filtering out large particles at the entrance of the transport section.