A predominant amount of energy needed in the industrial sector is in the form of heat. A significant number of industries in the world still relies on fossil fuels for meeting their heat requirements. A transition to renewable energy for heating needs is at a snail's pace due to fossil fuel lock-in, cost superiority of conventional fuels, and less government support for renewable technology for thermal requirements. The dairy industry is one of the sectors that need heat energy for its production process. This study deals with a techno-economic analysis on the integration of parabolic trough collectors in the dairy industry. The thesis finds the barriers for solar-thermal collectors to evolve in the dairy sector and the viewpoint of the dairy industry towards the acceptance of solar thermal for meeting their thermal needs. From a literature review, it is observed that the need for dairy product will increase in the coming year. To meet the demand, the production process has to be increased. For sustainable production, companies have to rely on environment-friendly energy sources to meet the thermal demand. In the thesis work, it was also found that for several solar fractions, the LevelizedCost of Heat (LCoH) of solar-assisted heating system is less than the LCoH of the fossil-fueled conventional boiler. Therefore, it is economically viable to integrate solar thermal collectors in the dairy industry. The project also compares the LCoHof solar-assisted heating system when solar integration is done at a) feed water heating, b) direct steam generation, and c) process integration. The effect of integration point on the solar fraction, LCoH, and carbon mitigation potential is presented for a real case dairy unit in Dubai. The simulations are performed using a dynamic simulation tool. Results show that minimum LCoH and solar fraction are achieved for process integration. The process integration results in up to 90 % of the solar fraction. Through process integration, the LCoH of the conventional boiler can be reduced by 60%.

La Simulation aux Grandes Echelles (SGE) est de plus en plus utilisée dans les processus de développement et la conception des réacteurs aéronautiques industriels. L'une des raisons pour ce besoin résulte dans la capacité de la SGE à fournir des informations instantanées d'un écoulement turbulent augmentant la quantité des prédictions de la composition des gaz d'échappement. Ce manuscrit de thèse aborde deux sujets récurrents de la SGE. D'une part, les schémas numériques pour la SGE nécessitent certaines propriétés, notamment une précision élevée avec une diffusivité faible pour ne pas nuire aux modèles de turbulence. Afin de répondre à ce pré requis, une famille de schémas d'intégration temporelle d'ordre élevée est proposée, permettant de modifier la diffusion numérique du schéma. D'autre part, la SGE étant intrinsèquement instationnaire, elle est très consommatrice en temps CPU. De plus, une géométrie complexe prend beaucoup de temps de simulation même avec les super calculateurs d'aujourd'hui. Dans le cas particulier d'intérêt et souvent rencontré dans les applications industrielles, l'approche bas-Mach est constitue une alternative intéressante permettant de réduire le coût et le temps de retour d'une simulation LES. L'impact et la comparaison des formalismes compressible et incompressible sont toutefois rarement quantifiés, ce qui est proposé dans ce travail pour une configuration représentative d'un brûleur swirlé industriel mesuré au CORIA / Large-Eddy Simulation (LES) becomes a more and more demanded tool to improve the design of aero-engines. The main reason for this request stems from the constraints imposed on the next generation low-emission engines at the industrial development level and the ability for LES to provide information on the instantaneous turbulent flow field which greatly contributes to improving the prediction of mixing and combustion thereby offering an improved prediction of the exhaust emission. The work presented in this thesis discusses two recurring issues of LES. For one, numerical schemes for LES require certain properties, i.e. low-diffusion schemes of high order of accuracy so as not to interfere with the turbulence models. To meet this purpose in the context of fully unstructured solvers, a new family of high-order time-integration schemes is proposed. With this class of schemes, the diffusion implied by the numerical scheme become adjustable and built-in. Second, since fully unsteady by nature, LES is very consuming in terms of CPU time. Even with today's supercomputers complex problems require long simulation times. Due to the low flow velocities often occurring in industrial applications, the use of a low-Mach number solver seems suitable and can lead to large reductions in CPU time if comparable to fully compressible solvers. The impact of the incompressibility assumption and the different nature of the numerical algorithms are rarely discussed. To partly answer the question, detailed comparisons are proposed for an experimental swirled configuration representative of a real burner that is simulated by LES using a fully explicit compressible solver and an incompressible solution developed at CORIA

Recursos Educacionais Abertos (REA) podem ser definidos como materiais de ensino, aprendizagem e pesquisa, em qualquer meio de armazenamento, que estão amplamente disponíveis por meio de uma licença aberta que permite reuso, readequação e redistribuição sem restrições ou com restrições limitadas. Atualmente, diversas instituições de ensino e pesquisa têm investido em REA para ampliar o acesso ao conhecimento. Entretanto, os usuários ainda têm dificuldades de encontrar os REA com os mecanismos de busca atuais. Essa dificuldade deve-se principalmente ao fato dos mecanismos de busca na Web serem genéricos, pois buscam informação em qualquer lugar, desde páginas de vendas até materiais escritos por pessoas anônimas. De fato, esses mecanismos não levam em consideração as características intrínsecas de REA, como os diferentes padrões de metadados, repositórios e plataformas existentes, os tipos de licença, a granularidade e a qualidade dos recursos. Esta dissertação apresenta o desenvolvimento de um mecanismo de busca na Web especificamente para recuperação de REA denominado SeeOER. As principais contribuições desta pesquisa de mestrado consistem no desenvolvimento de um mecanismo de busca na Web por REA com diferenciais entre os quais se destacam a resolução de conflitos em nível de esquema oriundos da heterogeneidade dos REA, a busca em repositórios de REA, a consulta sobre a procedência de dados e o desenvolvimento de um crawler efetivo para obtenção de metadados específicos. Além disso, contribui na inclusão de busca de REA no cenário brasileiro, no mapeamento de padrões de metadados para mecanismos de busca na Web e a publicação de uma arquitetura de um mecanismo de busca na Web. Ademais, o SeeOER disponibiliza um serviço que traz um índice invertido de busca que auxilia encontrar REA nos repositórios dispersos na Web. Também foi disponibilizada uma API para buscas que possibilita consultas por palavras chaves e o uso de palavras booleanas. A forma de validação em mecanismos de busca na Web, como um todo, e de forma quantitativa e específica por componentes foi feita em grau de especialidade. Para validação de qualidade foram considerados 10 participantes com grupos distintos de escolaridade e área de estudo. Os resultados quantitativos demonstraram que o SeeOER é superior em 23.618 REA indexados em comparação a 15.955 do Jorum. Em relação à qualidade o SeeOER demonstrou ser superior ao Jorum considerando a função penalizada e o score utilizada nesta pesquisa. / Open Educational Resources (OER) has been increasingly applied to support students and professionals in their learning process. They consist of learning resources, usually stored in electronic device, associated with an open license that allows reuse, re-adaptation and redistribution with either no or limited restrictions. However, currently the Web search engines do not provide efficient mechanisms to find OER, in particular, because they do not consider the intrinsic characteristics of OER such as different standards of metadata, repositories and heterogeneous platforms, license types, granularity and quality of resources. This project proposes a Web search engine, named SeeOER, designed to recover OER. Main features of SeeOER are: schema-level con ict resolution derived from the heterogeneity of OER, search for Brazilian OER repositories, query considering data provenance and the development of an effective crawler to obtain specific metadata. In addition, our project contributes to the inclusion of the search OER research issues in the Brazilian scenario, to the mapping of metadata standards to Web search engine. In addition, SeeOER provides a service which internally has an inverted index search to find the OER which is different from traditional Web repositories. We also provide an API for queries which make it possible to write queries based on keywords and boolean. The validation of the search engine on the Web was both qualitative and quantitative. In the quantitative validation it was observed in level of specialty of the search engines components. In conclusion, the quality and quantitative results experiments showed that SeeOER is superior in OER indexed 23,618 compared to 15,955 the Jorum. In relation to the quality SeeOER shown to be superior to Jorum 27 points considering the metric used in project.

The present work deals with the numerical solution of dynamic contact and fracture problems. The contact problem is a Signorini problem with or without Coulomb friction. The fracture problem uses a cohesive zone model with a prescribed crack path. These problems are characterized by a non-regular boundary condition and can be formulated with evolutionary variational inequations or differential inclusions. For the numerical solution, we combine, as usual in solid dynamics, a finite element discretization in space and time-integration schemes. For the contact problem, we begin by comparing the main methods proposed in the literature. We then focus on the so-called modified mass method recently introduced by H. Khenous, P. Laborde et Y. Renard, for which we propose a semi-explicit variant. In addition, we prove a convergence result of the space semi-discrete solutions to a continuous solution in the frictionless viscoelastic case. We also analyze the space semi-discrete and fully discrete problems in the friction Coulomb case. For the dynamic fracture problem, using a fully explicit scheme is impossible or not robust enough. Therefore, we propose time-integration schemes where the boundary condition is treated in an implicit way. Finally, we present and analyze augmented Lagrangian methods for static fracture problems

Recursos Educacionais Abertos (REA) podem ser definidos como materiais de ensino, aprendizagem e pesquisa, em qualquer meio de armazenamento, que estão amplamente disponíveis por meio de uma licença aberta que permite reuso, readequação e redistribuição sem restrições ou com restrições limitadas. Atualmente, diversas instituições de ensino e pesquisa têm investido em REA para ampliar o acesso ao conhecimento. Entretanto, os usuários ainda têm dificuldades de encontrar os REA com os mecanismos de busca atuais. Essa dificuldade deve-se principalmente ao fato dos mecanismos de busca na Web serem genéricos, pois buscam informação em qualquer lugar, desde páginas de vendas até materiais escritos por pessoas anônimas. De fato, esses mecanismos não levam em consideração as características intrínsecas de REA, como os diferentes padrões de metadados, repositórios e plataformas existentes, os tipos de licença, a granularidade e a qualidade dos recursos. Esta dissertação apresenta o desenvolvimento de um mecanismo de busca na Web especificamente para recuperação de REA denominado SeeOER. As principais contribuições desta pesquisa de mestrado consistem no desenvolvimento de um mecanismo de busca na Web por REA com diferenciais entre os quais se destacam a resolução de conflitos em nível de esquema oriundos da heterogeneidade dos REA, a busca em repositórios de REA, a consulta sobre a procedência de dados e o desenvolvimento de um crawler efetivo para obtenção de metadados específicos. Além disso, contribui na inclusão de busca de REA no cenário brasileiro, no mapeamento de padrões de metadados para mecanismos de busca na Web e a publicação de uma arquitetura de um mecanismo de busca na Web. Ademais, o SeeOER disponibiliza um serviço que traz um índice invertido de busca que auxilia encontrar REA nos repositórios dispersos na Web. Também foi disponibilizada uma API para buscas que possibilita consultas por palavras chaves e o uso de palavras booleanas. A forma de validação em mecanismos de busca na Web, como um todo, e de forma quantitativa e específica por componentes foi feita em grau de especialidade. Para validação de qualidade foram considerados 10 participantes com grupos distintos de escolaridade e área de estudo. Os resultados quantitativos demonstraram que o SeeOER é superior em 23.618 REA indexados em comparação a 15.955 do Jorum. Em relação à qualidade o SeeOER demonstrou ser superior ao Jorum considerando a função penalizada e o score utilizada nesta pesquisa. / Open Educational Resources (OER) has been increasingly applied to support students and professionals in their learning process. They consist of learning resources, usually stored in electronic device, associated with an open license that allows reuse, re-adaptation and redistribution with either no or limited restrictions. However, currently the Web search engines do not provide efficient mechanisms to find OER, in particular, because they do not consider the intrinsic characteristics of OER such as different standards of metadata, repositories and heterogeneous platforms, license types, granularity and quality of resources. This project proposes a Web search engine, named SeeOER, designed to recover OER. Main features of SeeOER are: schema-level con ict resolution derived from the heterogeneity of OER, search for Brazilian OER repositories, query considering data provenance and the development of an effective crawler to obtain specific metadata. In addition, our project contributes to the inclusion of the search OER research issues in the Brazilian scenario, to the mapping of metadata standards to Web search engine. In addition, SeeOER provides a service which internally has an inverted index search to find the OER which is different from traditional Web repositories. We also provide an API for queries which make it possible to write queries based on keywords and boolean. The validation of the search engine on the Web was both qualitative and quantitative. In the quantitative validation it was observed in level of specialty of the search engines components. In conclusion, the quality and quantitative results experiments showed that SeeOER is superior in OER indexed 23,618 compared to 15,955 the Jorum. In relation to the quality SeeOER shown to be superior to Jorum 27 points considering the metric used in project.

On s'intéresse à la résolution numérique de problèmes de contact et de fissuration en dynamique. Le problème de contact envisagé est le problème de Signorini avec ou sans frottement de Coulomb. Quant au problème de fissuration, il s'agit d'un modèle de zone cohésive avec trajet de fissuration pré-défini. Ces problèmes se caractérisent par la présence d'une condition aux limites non-régulière et se formulent comme des inéquations variationnelles d'évolution ou des inclusions différentielles. Pour les résoudre numériquement, nous combinons, comme il est courant en dynamique des solides, une discrétisation en espace par éléments finis et des schémas d'intégration en temps (de types différences finies). Pour le problème de contact, nous commençons par comparer les principales méthodes proposées dans la littérature. Nous étudions ensuite plus particulièrement la méthode dite de masse modifiée récemment introduite par H. Khenous, P. Laborde et Y. Renard. Nous en proposons une variante semi-explicite. Par ailleurs, nous prouvons un résultat de convergence des solutions semi-discrètes en espace vers une solution continue dans le cas d'un problème de Signorini sans frottement et d'un matériau viscoélastique. Nous analysons également les methodes semi-discrètes en espace et totalement discrètes dans le cas d'un problème de Signorini avec frottement de Coulomb. Pour le problème de fissuration dynamique, la non-régularité de la condition aux limites rend impossible ou peu robuste l'utilisation de schémas totalement explicites. Nous proposons donc des schémas où cette condition aux limites est traitée de façon implicite. Enfin, nous présentons et analysons des méthodes de lagrangien augmenté pour la résolution numérique du problème de fissuration en statique / The present work deals with the numerical solution of dynamic contact and fracture problems. The contact problem is a Signorini problem with or without Coulomb friction. The fracture problem uses a cohesive zone model with a prescribed crack path. These problems are characterized by a non-regular boundary condition and can be formulated with evolutionary variational inequations or differential inclusions. For the numerical solution, we combine, as usual in solid dynamics, a finite element discretization in space and time-integration schemes. For the contact problem, we begin by comparing the main methods proposed in the literature. We then focus on the so-called modified mass method recently introduced by H. Khenous, P. Laborde et Y. Renard, for which we propose a semi-explicit variant. In addition, we prove a convergence result of the space semi-discrete solutions to a continuous solution in the frictionless viscoelastic case. We also analyze the space semi-discrete and fully discrete problems in the friction Coulomb case. For the dynamic fracture problem, using a fully explicit scheme is impossible or not robust enough. Therefore, we propose time-integration schemes where the boundary condition is treated in an implicit way. Finally, we present and analyze augmented Lagrangian methods for static fracture problems

Cette thèse traite des équations de Maxwell en domaine temporel. Le principal objectif est de proposer des méthodes de type éléments finis d'ordre élevé pour les équations de Maxwell et des schémas d'intégration en temps efficaces sur des maillages localement raffinés. Nous considérons des méthodes GDDT (Galerkine Discontinues en Domaine Temporel) s'appuyant sur une interpolation polynomiale d'ordre arbitrairement élevé des composantes du champ électromagnétique. Les méthodes GDDT pour les équations de Maxwell s'appuient le plus souvent sur des schémas d'intégration en temps explicites dont la condition de stabilité peut être très restrictive pour des maillages raffinés. Pour surmonter cette limitation, nous considérons des schémas en temps qui consistent à appliquer un schéma implicite localement, dans les régions raffinées, tout en préservant un schéma explicite sur le reste du maillage. Nous présentons une étude théorique complète et une comparaison de deux méthodes GDDT localement implicites. Des expériences numériques en 2D et 3D illustrent l'utilité des schémas proposés. Le traitement numérique de milieux de propagation complexes est également l'un des objectifs. Nous considérons l'interaction des ondes électromagnétiques avec les tissus biologiques qui est au cœur de nombreuses applications dans le domaine biomédical. La modélisation numérique nécessite alors de résoudre le système de Maxwell avec des modèles appropriés de dispersion. Nous formulons une méthode GDDT localement implicite pour le modèle de Debye et proposons une analyse théorique et numérique complète du schéma. / This work deals with the time-domain formulation of Maxwell's equations. The main objective is to propose high-order finite element type methods for the discretization of Maxwell's equations and efficient time integration methods on locally refined meshes. We consider Discontinuous Galerkin Time-Domain (DGTD) methods relying on an arbitrary high-order polynomial interpolation of the components of the electromagnetic field. Existing DGTD methods for Maxwell's equations often rely on explicit time integration schemes and are constrained by a stability condition that can be very restrictive on highly refined meshes. To overcome this limitation, we consider time integration schemes that consist in applying an implicit scheme locally i.e. in the refined regions of the mesh, while preserving an explicit scheme in the complementary part. We present a full theoretical study and a comparison of two locally implicit DGTD methods. Numerical experiments for 2D and 3D problems illustrate the usefulness of the proposed time integration schemes. The numerical treatment of complex propagation media is also one of the objectives. We consider the interaction of electromagnetic waves with biological tissues that is of interest to applications in biomedical domain. Numerical modeling then requires to solve the system of Maxwell's equations coupled to appropriate models of physical dispersion. We derive a locally implicit DGTD method for the Debye model and we achieve a full theoretical and numerical analysis of the resulting scheme.