La conception des chambres de combustion industrielles (chambres de combustion aéronautiques, fours industriels, etc.) requiert une prédiction fine des phénomènes physiques dominants. En particulier, l’interaction flamme turbulence aux échelles résolues et non-résolues, l’impact de la composition et du mélange des réactifs, l’impact des pertes thermiques et de la diffusion différentielle doivent être capturés fidèlement. C’est dans ce contexte que le modèle de combustion turbulente F-TACLES (Filtered TAbulated Chemistryfor Large Eddy Simulation) a été développé afin de coupler une méthode de chimie tabulée (FPI) avec le formalisme de la simulation aux grandes échelles(LES).Dans cette thèse, le modèle F-TACLES, initialement développé pour des écoulements adiabatiques, est étendu à la prise en compte des pertes thermiques. Un formalisme adapté à l’utilisation de bases de chimie tabulée calculées avec la diffusion différentielle est aussi proposé. Ces développements sont validés sur deux configurations : le brûleur TSF et le brûleur SWB.La modélisation de l’interaction flamme-turbulence est ensuite étudiée. Une étude de sensibilité du modèle de plissement de sous-maille de Charlette et al. (2002) à ses paramètres et sous-modèles est réalisée sur le brûleur SWB.En particulier, une méthode d’estimation dynamique des paramètres est aussi évaluée et montre d’excellents résultats. Une généralisation du formalisme de la LES pour les écoulements réactifs est ensuite proposée afin de prendre en compte explicitement les deux filtres mis en jeu dans les simulations : le filtre associé à l’écoulement et le filtre associé à la flamme. Deux stratégies de fermetures sont proposées en se basant sur des modèles existants (F-TACLES et TFLES). Le modèle obtenu, appelé modèle F2-TACLES, est ensuite validé et comparé avec F-TACLES sur la configuration semi-industrielle PRECCINSTA.Pour terminer, la capacité du modèle F-TACLES à capturer l’impact des pertes thermiques et de la composition des gaz frais sur la topologie de flammes est évaluée. Cette étude est réalisée sur une série de flammes CH4-H2-Air turbulentes en giration et prenant des formes différentes en fonction du niveau de pertes thermiques et de la composition des réactifs. / The design of industrial combustion chambers (aeronautical engines, industrial furnaces, etc.) require a fine prediction of the different governing phenomena. Flame-turbulence interaction at resolved and unresolved scales, impact of reactants composition and mixing process, impact of heat losses and differential diffusion have to be correctly captured in such configurations. For that purpose,the turbulent combustion model F-TACLES (Filtered Tabulated Chemistry forLarge Eddy Simulation) has been developed to couple tabulated chemistry with large eddy simulation (LES) formalism.In this thesis, the F-TACLES model, initially developed for unity Lewis number and adiabatic flows, is extended to account for heat losses. A formalism allowing the use of chemical databases (1-D premixed flames) computed with differential diffusion is also proposed. The extended model is validated on two different configurations: the TSF burner and the SWB burner. Modeling of flame-turbulence interaction is then studied. For unresolved flame turbulence interactions, a sensitivity analysis of the Charlette et al. (2002) sub-grid scale wrinkling model to its own parameters and sub-models is performed on the SWB burner. A dynamic estimation of the model parameter is also assessed and showed very promising results. For resolved flame-turbulence interactions, a generalized formalism of the LES of reactive flows is proposed in order to account explicitly for both flame and flow filters. Two closure strategies are proposed based on the F-TACLES and TFLES models. The F2-TACLESmodel is then validated and compared to the original formulation of the FTACLES model. This study is performed on the lean premixed semi-industrial PRECCINSTA burner.The ability of the extended F-TACLES model to capture the impact of both heat losses and fresh gas composition on the flame topology is assessed. This study is conducted on a CH4-H2-Air turbulent and swirling flame series. These flames exhibit very different shapes depending on the level of heat losses and fuel composition.

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Emerging integration of renewable energy has prompted a wide range of research on the use of energy storage to compensate for the added uncertainty that accompanies these resources. In the Electric Reliability Council of Texas (ERCOT), compressed air energy storage (CAES) has drawn particular attention because Texas has suitable geology and also lacks appropriate resources and locations for pumped hydroelectric storage (PHS). While there have been studies on incorporation of renewable energy, utilization of energy storage, and dispatch optimization, this is the first body of work to integrate all these subjects along with the proven ability to recreate historical dispatch and price conditions. To quantify the operational behavior, economic feasibility, and environmental impacts of CAES, this work utilized sophisticated unit commitment and dispatch (UC&D) models that determine the least-cost dispatch for meeting a set of grid and generator constraints. This work first addressed the ability of these models to recreate historical dispatch and price conditions through a calibration analysis that incorporated major model improvements such as capacity availability and sophisticated treatment of combined heat and power (CHP) plants. These additions appreciably improved the consistency of the model results when compared to historical ERCOT conditions. An initial UC&D model was used to investigate the impacts on the dispatch of a future high wind generation scenario with the potential to utilize numerous CAES facilities. For all future natural gas prices considered, the addition of CAES led to reduced use of high marginal cost generator types, increased use of base-load generator types, and average reductions in the total operating costs of 3.7 million dollars per week. Additional analyses demonstrated the importance of allowing CAES to participate in all available energy and ancillary services (AS) markets and that a reduction in future thermal capacity would increase the use of CAES. A second UC&D model, which incorporated advanced features like variable marginal heat rates, was used to analyze the influence of future wind generation variability on the dispatch and resulting environmental impacts. This analysis revealed that higher amounts of wind variability led to an increase in the daily net load ramping requirements which resulted in less use of coal and nuclear generators in favor of faster ramping units along with reductions in emissions and water use. The changes to the net load also resulted in increased volatility of the energy and AS prices between daily minimum and maximum levels. These impacts were also found to increase with compounding intensity as higher levels of wind variability were reached. Lastly, the advanced UC&D model was also used to evaluate the operational behavior and potential economic feasibility of a first entrant conventional or adiabatic CAES system. Both storage systems were found to operate in a single mode that enabled very high utilization of their capacity indicating both systems have highly desirable characteristics. The results suggest that there is a positive case for the investment in a first entrant CAES facility in the ERCOT market. / text

Le traitement des conditions aux limites et la modélisation fine des interactions de sous-maille ont été abordés dans cette thèse. La formulation caractéristique des conditions aux limites a été analysée et une nouvelle procédure 3D-NSCBC est proposée qui autorise la prise en compte de l’évolution de la vitesse et de la pression dans le plan des frontières, afin d’introduire le caractère tridimensionnel de l’écoulement dans les conditions limites. Des nouvelles formulations pour resoudre le couplage des ondes caractéristiques au niveau des arêtes et des coins ont été développées. Dans le cadre de la Simulation des Grandes Échelles, pour reproduire correctement la dynamique de la turbulence à la paroi et pour mieux prendre en compte l'anisotropie du tenseur des contraintes de sous-maille, un modèle structural fondé sur l'hypothèse de similarité est développé pour des écoulements modérément compressibles et validé sur la simulation d'un jet rond en impaction sur une paroi plane. / The treatment of boundary conditions and sub-grid scale interactions’ modeling, with particular attention to the asymptotic behavior near the wall, were addressed in this thesis. The characteristic formulation of boundary conditions has been analyzed and a novel procedure 3D-NSCBC is proposed, which, accounting for the evolution of velocity and pressure on the boundary planes, allows a better representation of the three-dimensional character of the flow at the boundary. New formulations to solve characteristic wave coupling on edges and corners are developed. Within the framework of the Large-Eddy Simulation, in order to give a correct reproduction of near-wall turbulence dynamics and in order to better account for the sub-grid scale stress tensor’s anisotropy, a structural model based on the similarity hypothesis has been developed for weakly compressible flows and validated on the simulation of a round jet impinging over a flat plane.

The increasing amount of renewable energy sources is applying more and more pressure on today’s power system. Additionally, plannable sources of energy, which are mostly non-renewable, are being decommissioned at a high rate to combat climate change. The decommissioning of non-renewable producers and the increasing number of intermittent sources of energy are causing an increasingly volatile power system. In addition to the lack of plannable production, the inertia from synchronously rotating machines is decreasing due to the lack of contribution from renewable sources. The inertia of a power system assists in slowing down large frequency changes. When a notably large difference between production and consumption occurs in a power system with low inertia, components which can quickly counteract these effects by supplying the system with active power, are needed. The low inertia can also cause problems to the synchronicity of the synchronously rotating machines in the system, namely the rotor angle stability. A lack of rotorangle stability can cause the synchronicity of the synchronously rotating machines to be questioned. Fast frequency response units supply the power system with active power for a short period of time to reduce the rate of change of frequency and frequency deviation, which in turn allows the self-regulating units more time to adjust their production. Furthermore, these units can improve rotor angle stability. Such units can consist of batteries which are both serially and parallel connected with their associated control unit. This thesis aims to, with the help of the power system analysis program PowerFactory, and its associated dynamic simulation tools, formulate a methodology which can be used in power system models to locate the best placement for fast frequency response units. The results show that the formulated methodology can be used to find the best position of fast frequency response units for frequency deviation-, rate of change of frequency- and rotor angle stability support.

No description available.