Dissertations / Theses on the topic 'Chambre de combustion aéronautique'
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Arroyo, Callejo Gustavo. "Modélisation thermique avancée d’une paroi multiperforée de chambre de combustion aéronautique avec dilution giratoire." Thesis, Toulouse, ISAE, 2016. http://www.theses.fr/2016ESAE0008/document.
Ln the combustion chamber, temperatures up to 2000K are reached, which exceeds by far the melting point of the liner materials. ln order to protect the liner, cool air from the combustion chamber outer casing is injected into the combustor through a large number of sub-millimeter closely-spaced holes (effusion cooling). However, strict environmental legislation has led jet-engine manufacturers to consider techniques that reduce the quantity of air available for cooling. Therefore, cooling system must be carefully designed. However, the size of the holes makes detailed numerical simulations unaffordable. Aerothermal models that mimic effusion cooling behavior are a promising solution. On the Other hand, up to now, far too little attention has been paid to a novel effusion cooling technique (compound angle effusion cooling), where cold air injection is not aligned With the hot air flow direction. The aim of this dissertation is twofold: to establish an effusion cooling model and to investigate the flow field of compound angle effusion cooling
Godel, Guillaume. "Modélisation de sous-maille de la combustion turbulente : développement d'outils pour la prédiction de la pollution dans une chambre aéronautique." Phd thesis, INSA de Rouen, 2010. http://tel.archives-ouvertes.fr/tel-00557904.
Hervo, Loïc. "Simulation numérique de l’écoulement d’un mélange air et phase dispersée pour l’allumage d’une chambre de combustion aéronautique via un formalisme Euler Lagrange." Thesis, Toulouse, ISAE, 2017. http://www.theses.fr/2017ESAE0043/document.
The goal of this thesis is to contribute to the development and validation of numerical tools for the Large Eddy Simulation (LES) of the ignition of a turbulent multiphase flow in a combustion chamber. An energy deposition method that models the energy supplied by the spark plug to the flow was implemented in the CEDRE code. This method was validated on a simulation of the ignition of a purely gaseous laminar propane-air flow. Then, a LES of the non-reacting gas flow in the monosector combustor MERCATO was performed with the Navier-Stokes solver CHARME of the CEDRE code. The comparison between simulations and experiments demonstrates that the main flow field features are well reproduced. In order to simulate the non-reacting dispersed two-phase flow of the same configuration, a simplified injection method called FIMUR was implemented in the Lagrangian solver SPARTE of the CEDRE code. In this method, droplets are injected directly at the tip of the injector with velocities deduced from experimental correlations while the size distribution is directly obtained from experimental data. The comparison of the mean droplet velocity and diameter fields in the vicinity of the injector between simulations and experiments appears satisfactory. Finally, LES's of the ignition of the MERCATO were performed using the non-reacting two-phase flow simulations and the aformentioned energy deposition method. Depending on the instant of energy deposition, the simulations lead to successful or failed ignitions. The flame propagation in a successful ignition was analysed in order to attempt to determine the physical phenomena at play and to better understand them
Burguburu, Joseph. "Etude expérimentale de la stabilité d'une flamme dans une chambre de combustion aéronautique par recirculation de gaz brûlés et par ajout d'hydrogène." Phd thesis, INSA de Rouen, 2012. http://tel.archives-ouvertes.fr/tel-00771860.
Burguburu, Joseph. "Etude expérimentale de la stabilité d’une flamme dans une chambre de combustion aéronautique par recirculation de gaz brûlés et par ajout d’hydrogène." Thesis, Rouen, INSA, 2012. http://www.theses.fr/2012ISAM0010/document.
Environmental standards on aircraff NOx emissions are strict. Technics for reducing them have drawbacks. Two options are explored in this study to supress them. The first one is to fundamentally change the current combustion chamber architecture, to stabilize them by a cavity, the second, to dope fuel at idle.Little information on the mechanisms of stabilization and on the flame structure on Trapped Vortex Combustor is available. To remedy this, a TVC is built. The stabilizing ans destabilizing parameters are pointed out by the cold flow investigation and the temporally resolved study of the combustion. The impact of the flame structure on pollutant emissions is also considered.The second part of this stud, deals with the addition of pure hydrogen an of reformer gas in a conventional combustuion chamber. Despite a slight increase in NOx emissions, the addition of hydrogenated compounds reduces drastically CO emissions, increases the flame stability and reduces the LBO limit
Royer, Alex. "Amélioration des méthodes de calcul thermique par réseau de neurones dans les chambres de combustion aéronautiques." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0141.
Aeronautical combustion chambers are constrained environments operating at temperatures and pressures that have been steadily increasing over the last decades. Under these conditions, radiative heat transfer is significant and its influence on flame structure and wall temperatures is noticeable. It is therefore essential to be able to accurately model this transfer mode on very heterogeneous industrial cases and on mesh of several hundred million cells. Common resolution methods do not provide satisfactory accuracy in view of the growing needs. A fine resolution and the use of spectral gas models would be necessary but would imply a prohibitive consumption of computing resources.To overcome this problem, we propose in this work a new radiation modelling methodology based on Monte Carlo methods and Bayesian neural networks. The principle of the concept detailed in this manuscript starts with the sampling of reference points randomly drawn in the study domain. The radiative quantity of interest is computed at each of these points using a Monte Carlo method and a fine spectral model. The results of these calculations are then stored in a database on which a neural network is trained using a Levenberg-Marquardt algorithm. The Bayesian paradigm allows us to define the optimal topology of the network and to automatically adapt the set of parameters inherent to the network without user intervention. The trained network allows to reconstitute the flux or flux divergence fields within the domain. After a theoretical description of the notions used in this work, results on academic cases are presented in different configurations. We then demonstrate the ability of the developed method to model radiation in a participatory environment with very high accuracy and low computational costs
Guignard, Olivier. "Vers une modélisation combinée des échanges thermiques conductifs, convectifs et radiatifs dans des chambres de combustion aéronautiques." Ecully, Ecole centrale de Lyon, 2005. http://bibli.ec-lyon.fr/exl-doc/oguignard.pdf.
The temperature levels reached in modern jet engines threaten the mechanical hold-up of confining walls. Air bleeding is necessary, which deteriorates the global aerothermal efficiency. In order to optimize it, designers use more and more elaborate numerical descriptions. In order to reproduce interactions between the various significant heat transfer modes, the corresponding simulation codes must exchange their outputs. However "coupling" type approaches remain very expensive from a computing point of view. "Chaining" type techniques could allow to approach the termal properties of the flow at a reduce cost. A methodology for the determination of the convection coefficient for cooling films is examined. Theoretical study and a practical application allow to underscore the conceptual error this methodology is suffering from. An alternative methodology is proposed to correct this error
Duchaine, Florent. "Optimisation de Forme Multi-Objectif sur Machines Parallèles avecMéta-Modèles et Coupleurs. Application aux Chambres de Combustion Aéronautiques." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2007. http://tel.archives-ouvertes.fr/tel-00362811.
Le but de ces travaux de thèse est de fournir une méthodologie basée sur des considérations issues de l'optimisation multi-objectif pour développer un outil de conception automatisé qui intègre des codes de simulation numérique pour évaluer les configurations. En premier lieu, les études concernent l'automatisation des procédures de simulation en insistant sur les aspects de génération automatique de maillage. Ensuite, le problème des temps de restitution liés à l'utilisation conjointe de techniques d'optimisation et de codes de calcul coûteux en ressources informatiques est adressé en proposant un algorithme basé sur des méta-modèles. L'outil final est construit à partir d'un coupleur de codes parallèles, lui conférant ainsi des caractéristiques intéressantes de performance et de flexibilité. Finalement, après divers tests de validation et d'évaluation, une application sur une chambre de combustion industrielle montre les capacités de la méthode à identifier des configurations prometteuses.
Dorey, Luc-Henry. "Modélisation des phénomènes couples combustion-formation des suies-transferts radiatifs dans les chambres de combustion de turbine à gaz." Phd thesis, Ecole Centrale Paris, 2012. http://tel.archives-ouvertes.fr/tel-00731144.
Dufitumukiza, Jean Pierre. "Développement des techniques optiques pour la caractérisation in-situ de la suie dans des foyers de combustion à haute pression." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2023/2023ULILR010.pdf.
The growth of air traffic urges combustion research to get a detailed understanding of the physical and chemical processes occurring in the aircraft engine; the main objectives are 1) to improve the combustion process and 2) to lower gaseous and particulate emissions. A solution to the first issue lies in the combustion at higher pressure and temperature, but this can impact the second issue, particularly concerning the production of soot and NOx emissions. To find a solution, it is necessary to develop experimental tools applied in representative combustion conditions relative to those encountered in aircraft engines in order to capture complex phenomena occurring inside these engines. To do this, a semi-industrial aeronautical test rig equipped with suitable optical diagnostics implemented/available at ONERA Palaiseau offers a glimpse of information into these combustion processes. As a result, this research aims to develop and implement optical techniques for characterizing soot particles in aeronautical engine-relevant combustors. Laser-Induced Incandescence (LII) is the primary technique on which efforts are directed. This technique is based on Planck's law radiation model. LII technique is used due to its high sensitivity for detecting the soot volume fraction and flexibility for its implementation in various optical configurations. In addition, the coupling of LII with other optical techniques presents a high interest in understanding the mechanisms and parameters leading to soot formation. First, Laser-Induced Fluorescence (LIF) is added as a complementary technique to detect soot precursors known as Polycyclic-Aromatic Hydrocarbons (PAHs). Secondly, light scattering provides information on the distribution of unburnt liquid fuel droplets and possible soot particle localization inside the combustor. Thirdly, OH* chemiluminescence illustrates the reaction zone and heat release. Finally, the PAHs and soot transportation or interactions with the flow field are tackled via particle image velocimetry (PIV)
Lambert, Océane. "Solutions architecturées par fabrication additive pour refroidissement de parois de chambres de combustion." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI048/document.
Combustion chamber walls are perforated with holes so that a cooling air flow can be injected through them. The wall is cooled by convection and an insulating film is created on the hot surface (film cooling). This PhD thesis aims to use the possibilities of additive manufacturing to provide new architectured solutions that could enhance the internal heat exchanges, and lead to a higher cooling effectiveness.The first approach is to develop new designs of multiperforated walls by Electron Beam Melting (EBM) and Selective Laser Melting (SLM) used at the resolution limits of the processes. They are characterized by microscopy, X-ray tomography and permeability tests. Some aerothermal simulations help understanding the effects of these new designs on the flow and on heat exchanges. These results lead to a geometry adaptation.The second approach is to simultaneously manufacture an architectured part with dense and porous zones by EBM. Thanks to image analysis combined with large field EBSD, it is possible to investigate the mechanisms leading to the porous zones and to link them to permeability and porosity. The film cooling effect could be favoured by the orientation of pores towards the cooling flow. Therefore, a new powder-based manufacturing process named Magnetic Freezing, where metallic powders organize into an oriented structure thanks to a magnetic field, is developed.The various solutions studied during this thesis are tested on an aerothermal bench. They all show a more efficient and homogeneous cooling than the industrial reference. Some first tests on one of the selected solutions are performed on a combustion bench. This lighter and more permeable structure proves to be a solution as efficient as the industrial reference at a given flow rate. It should therefore be a more efficient solution for a given overpressure
Vignat, Guillaume. "Injection and combustion dynamics in swirled spray flames and azimuthal coupling in annular combustors." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASC024.
The deployment of low-emission technologies in aero-engines does not only require that new designs produce reduced amounts of pollutants, but also that their dynamical behavior (ignition, blow-off, and combustion instabilities) be compatible with the high safety standards prevailing in aeronautics. This research is focused on the latter aspect of combustor design. A transparent annular combustor equipped with 16 swirled spray injectors is used to represent at the laboratory scale the combustion chamber of a jet engine. This system is used in conjunction with a single sector rig to investigate dynamical issues.Theory, experimentation and large eddy simulation are combined to examine a range of items pertaining to the injector dynamics, flow structure, swirl number determination, spray characteristics, and coupling between injector flow and acoustic field. A database of injectors is introduced to investigate the impact of injection parameters on combustion dynamics. These injectors are examined under steady and unsteady conditions by combining laser diagnostics and high-fidelity simulations which allows the characterization of spray-specific behaviors of relevance to the dynamics of injection systems. One important result is that the presence of a liquid film formed on the wall of the injection unit gives rise to a multi-modal distribution of droplet velocities. A novel method is introduced to examine the space-time behavior of the flow and flame of a swirling injector submitted to axial modulations. A detailed investigation of the process by which convective perturbations couple with the acoustic field allows to examine the time lags that control combustion instability and sort out the respective roles of convection and droplet spray evaporation. High speed tomography relying on SnO2 particles provides major results on the Precessing Vortex Core structure and show its behavior under acoustic forcing. The impact of injector head loss on combustion instabilities is examined using several injection systems with similar levels of swirl. The head loss is shown to play a major role in the coupling between the flame and the upstream plenum. The previous results obtained in a single sector rig are used to guide experiments on the annular combustor. The focus is placed on high amplitude combustion oscillations coupled by a standing azimuthal mode inducing flame blow-off near the pressure nodal line. The deformation of the acoustic distribution is tracked using a novel expansion on azimuthal harmonics allowing the determination of the critical conditions leading to this phenomenon. New results are also presented about the transient dynamics of an injector during ignition and about lean blow out with a proof of concept extension of the LBO limit by nanosecond plasma discharges
Gullaud, Elsa. "Simulation et calcul des modes thermo-acoustiques des chambres de combustion aéronautiques." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20136/document.
Aeronautical engine constructors are using lean premixed regimes to deal with the necessity to cut down pollutant emissions. These regimes indeed help to prevent the emission of NOx but trigger on the other hand combustion instabilities. Numerical simulation (which can consist of LES or Helmholtz solvers for example) has proven to be a usefool tool to predict these instabilities at the design stage. Acoustic modes can be well predicted only if geometrical details are taken into account. Multiperforated plates which equip combustion chambers with the purpose of cooling the inner walls must for instance be taken into account in a numerical calculation. These plates consist of several apertures with a diameter smaller than 1 millimeter, which makes their meshing impossible. The objective of this thesis is to take into account perforated plates in the numerical simulation of the acoustics of combustion chambers. The homogeneous model for the acoust ic behaviour of a perforated plate derived by Howe in 1979 is used. Provided some hypotheses, this model can predict the acoustic behaviour of a plate under an acoustic excitation. Howe's model, derived in an incompressible flow, is here adapted to be used in the case where the perforated plate in located between the casing (cold air) of a combustion chamber and the inner chamber (filled with a hot mixture). The model is well suited to be implemented in an existing 3D Helmholtz solver, because it appears under the form of an impedance. The coding is validated by comparing numerical results to analytical results on simple geometries. First results allow to show the damping behaviour of perforated plates and its dependance to geometric parameters or the speed of the incoming flow though the apertures.Acoustic instabilities can also be apprehended with an acoustic energy approach. Since industrial chambers are equipped with several pairs of multiperforated plates, it is interesting to show which of them are the most efficient at damping purposes. An acoustic energy budget allows to predict the percentage of the total damping a particular plate is responsible for. In the presence of a flame, the acoustic energy budget can also give information on the contribution of the flame on the triggering or damping of the instability.An industrial chamber designed by Turbomeca for a helicopter is computed. The acoustic energy budget on a computation taking into account the active flame and the multiperforated plates allows to predict the stability of the modes of the chamber. The elements responsible for the behaviour of the instability can be identified. This work has been funded by SNECMA and the code used to implement the model is AVSP, it co-belongs to CERFACS and SNECMA
Delmas, Simon. "Simulation numérique directe d'un jet en écoulement transverse à bas nombre de Mach en vue de l'amélioration du refroidissement par effusion des chambres de combustion aéronautiques." Thesis, Pau, 2015. http://www.theses.fr/2015PAUU3035/document.
In this work we are interested in jet in crossflow in a generic configuration to the one used in effusion cooling for combustion chambers. Improved wall models with mass transfer requires a better knowledge of the interaction between the jets and the main flow. We therefore carried out the direct numerical simulation of a jet issuing from an inclined hole with or without gyration, for isothermal turbulent flow at low Mach number, in a compressible context. To achieved this, we worked with the continuous and discontinuous finite element library : AeroSol on hybrid grid. In particular we studied the stability of numerical flux for the unsteady compressible flow associated with discontinuous Galerkin method when the Mach number tends to zero. We were able to demonstrate unstable behavior when using explicit time discretization and we corrected them by providing a new flux. In a second time, we have performed the necessary development to achieve the calculations. We have been especially interested in the generation of a synthetic turbulent velocity field using the SEM method (Synthetic Eddy Method) that we have implemented in aerosol and validate. Thanks to the developed post-processing tools, we have conducted an analysis of our results. In the case without gyration, comparisons with experimental results and the results of RANS simulations we obtained on the Maveric test-bench configuration are encouraging. The mean flow of the jet is correctly reproduced. In the case with gyration, the expected behavior of successive deflection of the jet in both planes (injection plane and transverse plane of the flow) is reproduced and shows all the potential of the AeroSol library we helped to develop
Frenillot, Jean-Philippe. "Etude phénoménologique des processus d‟allumage et de stabilisation dans les chambres de combustion turbulente swirlées." Phd thesis, INSA de Rouen, 2011. http://tel.archives-ouvertes.fr/tel-00669522.
Lapeyre, Corentin. "Numerical study of flame stability, stabilization and noise in a swirl-stabilized combustor under choked conditions." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14493/1/Lapeyre.pdf.
Leyko, Matthieu. "Mise en œuvre et analyse de calculs aéroacoustiques de type SGE pour la prévision du bruit de chambres de combustion aéronautiques." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0082/document.
An important part of the noise generated by aero-engines is caused by the combustion. To decrease this source of noise, a precise comprehension of the underlying phenomenon is required. Two different mechanisms generating noise in aero-engines because of the combustion have been identified in the 1970’s: the direct mechanism that is directly related to the unsteady heat release, and the indirect one that is caused by the interactions between the turbine stages and the temperature fluctuations also produced by the combustion. Analytical methods and numerical simulations are used here both to show the importance of the indirect combustion noise compared with the direct one, and to provide some validity limits of compact nozzles analytical approaches. Three different configurations dealing with indirect noise are investigated: quasi-1- D nozzle, axisymmetric 2-D nozzle and 2-D turbine blade. Finally, an actual 3-D combustion chamber sector (SNECMA) is addressed with Large-Eddy Simulation. Fluctuations at the outlet of the combustor are used to compute the overall noise caused by the combustion (direct and indirect), by means of the investigated analytical models
Duchaine, Florent. "Optimisation de forme multi-objectif sur machines parallèles avec méta-modèles et coupleurs : application aux chambres de combustion aéronautiques." Phd thesis, Toulouse, INPT, 2007. http://oatao.univ-toulouse.fr/7706/1/duchaine.pdf.
Pecquery, François. "Développement d'un modèle numérique de prédiction des émissions d'oxydes d'azote pour la simulation aux grandes échelles de chambres de combustion aéronautiques." Phd thesis, INSA de Rouen, 2013. http://tel.archives-ouvertes.fr/tel-00949132.
Cuif, Sjöstrand Marianne. "Simulations Numériques Directes d’une méso-chambre de combustion : Mise en oeuvre et analyses." Thesis, Rouen, INSA, 2012. http://www.theses.fr/2012ISAM0022/document.
Meso-combustion can be defined as the combustion regime where the involved lenghts scales are close but slightly larger than the quenching distance of the flame, tipically smaller than a cm. By taking advantage of the high energetic density of liquid hydrocarbons, it would become possible to build small-sized combustion-based long-lived lighter electrical power systems. However combsution phenomena at these meso-scales have their own shortcomings. Indeed, by decreasing the system size, the usual phenomenological balance betwenne chemical reactions, mixing, turbulence and heat transfer is changed. In the present work, we focus on the DNS calculation of a cubic meso-combsution chamber of 8 x 10 x 8 mm3. This works presents the implementation of the numerical strategy used, with a specific attention to the no-slip wall compressible boundary condition. We then present an analysis of this particular reactive flow. The results are useful for future modeling of such a combustor
Foulon, Christian. "Etude numérique et expérimentale du comportement thermique d'une paroi multiperforée mince ; application au refroidissement pariétal des chambres de combustion de moteurs aéronautiques." Poitiers, 1999. http://www.theses.fr/1999POIT2334.
Guedot, Lola. "Développement de méthodes numériques pour la caractérisation des grandes structures tourbillonnaires dans les brûleurs aéronautiques : application aux systèmes d'injection multi-points." Thesis, Rouen, INSA, 2015. http://www.theses.fr/2015ISAM0017/document.
The reduction of pollutant emissions of aeronautical devices requires to optimize the design of the injection systems in the combustion chamber. The objective of this work is to improve the understandingof the flow dynamics in swirl stabilized burners. Large Eddy Simulation has become a major tool for the analysis of such flows. The steady increase in computational power enables to perform high-fidelity simulations, that generates a large amount of data, making it difficult to extract relevant information regarding the large scale phenomena. To this aim, massively parallel post-processing methods, suited for complex geometries, were developed in order to extract large-scale structures in turbulent flows. These methods were applied to simulations of spray flames in swirl burners, to get a better insight of how the large scale structures interact with the flame topology and the spray dynamics
Moreau, Denis. "Etude de mélange de jets gazeux dans une chambre de combustion." Rouen, 1988. http://www.theses.fr/1988ROUES043.
Kechabia, Rachid Alexandre. "Etude experimentale et numerique d'une chambre de combustion de laser chimique." Paris 6, 1992. http://www.theses.fr/1992PA066195.
Moreau, Denis. "Etude de mélange de jets gazeux dans une chambre de combustion." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37616639q.
Paulhiac, Damien. "Modélisation de la combustion d’un spray dans un brûleur aéronautique." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14495/1/paulhiac_partie_1_sur_2.pdf.
Nualas, Florence. "Fonctionnement en oxydation de matériaux composites céramiques (CMC) dans des environnements aéronautiques." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00993488.
Mazur, Marek. "Etude expérimentale du bruit de combustion dans un foyer de type aéronautique." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLC034/document.
Combustion noise has become an increasing contributor of overall aircraft engine noise. It consists of two major parts, direct and indirect combustion noise. The former is generated by the heat release fluctuations of the flame itself. The latter is generated by the temperature inhomogeneities in the burnt gases, which are accelerated in the turbine stages or nozzle following the combustion chamber.The aim of this work is to design and build a pressurized lean swirling combustor test bench, in order to quantify the two contributions.The combustor is thus supposed to generate high quantities of indirect combustion noise. The second aim is then to determine the contributions of direct and indirect combustion noise quantitatively and to gain insight about the sources of the two contributions. These analyses are conducted by different high-speed diagnostics, which were worked on during this work. These diagnostics allow to characterize the flow fields and flame dynamics, to put forward the combustion instability in the system and finally to quantify the direct and indirect combustion noise contributions
Florenciano, Merino Juan Luis. "Étude de la réponse d'un écoulement avec transfert pariétal de masse à un forçage acoustique : application au refroidissement des chambres de combustion aéronautiques." Thesis, Pau, 2013. http://www.theses.fr/2013PAUU3013/document.
This experimental and numerical study in the field of fluid mechanics deals with jets-in cross flow configurations that are relevant for the cooling of aero engine combustion chambers. Indeed, in presence of instabilities it is important to determine to which extent the film cooling is able to do its job of preserving the combustion chamber walls from the thermal load. The test facility MAVERIC has been upgraded in order to acoustically force the crossflow in which the jets are discharging. The strong sensitivity of the overall flow unsteady properties to the presence of the acoustic forcing has been clearly evidenced. The agreement between the experimental results and large-eddy simulations proved to be quite encouraging for a stationary acoustic wave whereas the case of a propagating acoustic wave investigated only numerically reveals also quite a significant change of the flow topology. In this context, the effect of the acoustic forcing on the wall thermal behavior has been analyzed thanks to the use of the fluid-solid coupled AVBP-AVTP solver
Emidio, Jean Manuel. "Refroidissement pariétal par multiperforations : Détermination de lois d'efficacité de refroidissement dans les conditions réelles de fonctionnement de chambres de combustion de turbines aéronautiques." Pau, 1998. http://www.theses.fr/1998PAUU3030.
The increase of turbomachines performances goes through the augmentation of pressures and working temperatures, therefore by high thermal stresses on hot parts, particularly on combustion chambers. Thermomechanical behaviour of these parts require the improvement of parietal cooling methods efficiency. The multiperforation cooling method, seems to present an important potential of optimisation as well on a conception way than on a realisation way. In order to predict the local temperature evolutions among a new cooled combustion chamber walls, it is necessary to know the wall heat transfer limit conditions in the film cooling. A new method for the calculation of local convective heat transfer coefficient and adiabatic wall temperature operating in real cases, and a modelisation of heat transfer on a multihole plate, including an optimal research by a Nelder Mead simplex method and a neural network has been developed in the "Laboratoire Aquitain de Recherche en Aérothermique"
Courtois, Raphaël. "Simulation aux grandes échelles de l'écoulement dans un chambre de combustion en forme de marche descendante." Châtenay-Malabry, Ecole centrale de Paris, 2005. http://www.theses.fr/2005ECAP1004.
The large Eddy Simulation (LES) has been used ti simulate the flow in a backward facing step combustor. The LES allows to investigate the unsteady phenomena and, in particular, the interaction of the flame with the flow. The use of LES for reacting flows is recent because is started in the middle of ninety’s. For that reason many validation studies continue to be undertaken. In this thesis, the experimental backward facing step chamber, named A3C, has been chosen. Many measurements have been carried out in the LAERTE (ONERA) and have given rise to important data basis in mean temperature (DRASC) and mean velocity (LDV). These results are compared with our LES simulations. The unsteady phenomena appearing in the simulations are also analysed. The AVBP code developed by the CERFACS has been used for these simulations. Initially, our study concerned the simplified case of non reactive flow. Twodimensional simulations have been first carried out to learn the use and the behaviour of the AVBP code. Then, more realistic tridimensional calculations have been carried out in order to validate the code. In a second time, the combustion has been introduced by the means of the thiskened flame model. Twodimensional simulations have been first undertaken in order to evaluate the reliability of such calculations. Then, tridimensional simulations have been achieved in order to take into account the influence of the tridimensional turbulence in front flame. These tridimensional simulationshave a very high coast and their interest is discussed
Fortier-Topping, Hugo. "Conception d'une chambre de combustion pour la microturbine à gaz SRGT-2." Mémoire, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/5417.
Erchiqui, Fouad. "Modelisation mathematique d'une chambre de combustion par la methode des plans imaginaires." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1987. http://theses.uqac.ca.
En tete du titre: Memoire presente a l'Universite du Queec a Chicoutimi comme exigence partielle pour l'obtention du grade de maitre es sciences appliquees. CaQCU Bibliogr.: ff. 60-61. Document électronique également accessible en format PDF. CaQCU
Champion, Jean-Louis. "Etude expérimentale des films pariétaux de refroidissement produits par une paroi multiperforée - cas des conditions de fonctionnement des chambres de combustion de moteurs aéronautiques." Poitiers, 1997. http://www.theses.fr/1997POIT2297.
Alizon, Franck Pascal. "Transferts de chaleur convectifs dans la chambre de combustion des moteurs à combustion interne : Influence de l'aérodynamique interne." Paris 6, 2005. http://www.theses.fr/2005PA066116.
Aligrot, Catherine. "Etude expérimentale et théorique du délai d'auto-inflammation de différents carburants dans une chambre de combustion à volume constant." Ecully, Ecole centrale de Lyon, 1994. http://bibli.ec-lyon.fr/exl-doc/TH_T1549_caligrot.pdf.
Cuif, Sjöstrand Marianne. "Simulations Numériques Directes d'une méso-chambre de combustion : Mise en oeuvre et analyses." Phd thesis, INSA de Rouen, 2012. http://tel.archives-ouvertes.fr/tel-00845259.
Bénard, Pierre. "Analyse et amélioration d'une chambre de combustion centimétrique par simulations aux grandes échelles." Thesis, Rouen, INSA, 2015. http://www.theses.fr/2015ISAM0018/document.
Designing a meso-scale combustion system remains a challenging scientific and technological issue. Increasing the surface-to-volume ratio promotes wall heat losses, reduces the residence time and turbulence intensity. The main objective of this thesis is to understand the physical phenomena involved in the centimetre-sized asymmetric whirl cubic burner of 8 x 10 x 8 mm3 (millimètre cube) and develop specific adapted numerical tools. The methane/air reactive flow is studied using detailed LES. While fuel and air are injected separately, combustion takes place in the premixed regime. However combustion is far from being complete, causing low combustion efficiency and significant emissions of pollutants. The second objective is to adapt in the best possible way the performances of this burner. Hydrogen enrichment of the fuel mixture showed significant efficiency enhancement and reduced pollutant emissions. Several other combustor geometries are also studied, paving the way for future improvement
Gosselin, Pierre. "Prédiction du transfert thermique pariétal pour la chambre de combustion d'une turbine à gaz." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0015/NQ47570.pdf.
Lengyel, Igor. "Caractérisation des échelles de longueur turbulentes dans la chambre d'un moteur à combustion interne." Ecully, Ecole centrale de Lyon, 1995. http://www.theses.fr/1995ECDL0015.
The aim of this work is to study the behaviour of turbulence length scales in an internal combustion engine. This is achieved by using both theoretical and experimental approaches. The theoretical approach is based one-dimensional compression and expansion stroke modelling ; the evolution of turbulent ccharacteristics during these strokes of the engine cycle is deduced by using different statistical models of variable complexity (one-point and two-point models). At first we use a one-point homogeneous turbulence model in the presence of a one-dimensional compression (or expansion). The evolution of the characteristic times of different physical mechanisms predicted by this model justify the application of the rapid distortion theory (RDT) during the expansion stroke. The anisotropy of the integral length scales is deduced from the two-point model. The experimental approach consists of the direct measurement of the spatial correlation coefficient of velocity fluctuations by two-point Laser Doppler Anemometry. The spatial resolution analysis shows the limitations of the experimental set-up for the Taylor length scale measurement. Measurements are made of two different integral length scales at different points in the chamber during the induction, compression and expansion strokes. The influence of different parameters (engine velocity, compression ratio, swirl) is studied. Good agreement between experimental and theoretical (RDT) results is obtained during the expansion stroke. Wall effects at the end of compression stroke are also analysed. Different filtering methods are compared with the ensemble average method in order to remove cyclic fluctuations. Comparisons are made in a particular case where cyclic fluctuations are clearly linked to a large scale motion (swirl precession) superimposed on the turbulent field
GOBIN, BENOIT. "Modelisation tridimensionnelle de la chambre de combustion et du circuit de refroidissement des moteurs." Nantes, 2000. http://www.theses.fr/2000NANT2047.
Lacoste, Deanna. "Etude expérimentale de la combustion de mélanges stratifiés globalement pauvres en chambre à volume constant." Poitiers, 2002. http://www.theses.fr/2002POIT2331.
This experimental study deal with a stratified fuel / air gaseous mixture combustion in a constant volume parallelepipedic chamber. The fuel composition is: 95% propane and 5% acetone. The stratification is obtained by an injection of pure fuel (using a planar injector) in the combustion chamber which is initially full of air at atmospheric pressure. The ignition is obtained by an electrical spark at the centre of the combustion chamber. The optical diagnostics used during this study are: P. L. I. F. , using acetone as a tracer, Tomography and P. I. V. , using oil droplets as tracers. Simultaneous measurements of the fuel / air ratio, the velocity in the unburned gases and the location of the flame front have been carried out. The stratification influence on the flame front propagation has been shown
Tremoulière, Gérard. "Contribution à l'étude des transferts thermiques dans la chambre de combustion d'un moteur Diesel : Analyse hors moteur du jet pariétal en combustion." Lyon 1, 1985. http://www.theses.fr/1985LYO19027.
Etude theorique et experimentale d'un jet de methane en incidence normale sur une paroi chaude
Legier, Jean-Philippe. "Simulations numériques des instabilités de combustion dans les foyers aéronautiques." Toulouse, INPT, 2001. http://www.theses.fr/2001INPT029H.
Rouvreau, Stéphane. "Etude expérimentale de la structure moyenne et instantanée d'un film produit par une zone multiperforée sur une paroi plane : application au refroidissement des chambres de combustion des moteurs aéronautiques." Poitiers, 2001. http://www.theses.fr/2001POIT2287.
Delorme, Thierry. "Pyrométrie polychromatique appliquée à l'analyse de la combustion et de la production des suies et des NOx dans une chambre de combustion diesel." Ecully, Ecole centrale de Lyon, 1993. http://bibli.ec-lyon.fr/exl-doc/TH_T1557_tdelorme.pdf.
Fabert, Emilie. "Analyse des écoulements dans un ensemble "roue directrice de sortie, diffuseur, tête de chambre de combustion"." Ecully, Ecole centrale de Lyon, 2009. http://www.theses.fr/2009ECDL0016.
The studied facility concerns a set of "outlet guide vane, diffuser, combustion chamber". This should realize a good recovery of static pressure under different feeding and bleed conditions. In deed, the reduction of the axial dimensions and the decrease of losses are a major issue in the design of new engines, and the improvement of performance of such devices can be achieved only through an understanding of phenomena occurring in these elements. It is also essential to take into account their interactions. This experimental study offers the possibility to perform detailed and comprehensive measures of the influence of upstream and downstream conditions on a combustor diffuser by testing modular configurations with more and more complex option settings (bypass flow). Some tested configurations can generate incident flows with several levels of turbulence. The isovalue maps of aerodynamic magnitudes and parietal pressure survey can be obtained between the different sections for all tested configurations. Parietal visualizations are possible within the diffuser. This study will also review the results gained with the pressure probe mainly used, and corrections to the flow angles will be proposed on the basis of laser measurements. These stereoscopic PIV measurements are performed in a configuration to overcome the problems of optical access and will be validated by the establishment of a criterion based on continuity
Miron, Petre. "Etude expérimentale des lois de parois et du film de refroidissement produit par une zone multiperforée sur une paroi plane. : Application au refroidissement des chambres de combustion des moteurs aéronautiques." Pau, 2005. http://www.theses.fr/2005PAUU3030.
The optimisation of turbocraft combustion chamber cooling systems is nowadays one of the main challenges engineers have to deal with. The current work presents an experimental aerodynamic study of the multiholed cooling technique on a 10:1 scale flat plate. A great deal of attention has been paid during the development of the test rig to obtain clearly identified boundary conditions that are necessary to perform a relevant comparison between the present experimental results and related numerical simulations. LDA velocity measurements allowed to investigate the blowing rate and Reynolds number influence on the film cooling evolution in the middle and downstream the perforated zone. The kidney shape and the contra rotating pair vortex are investigated and then friction velocity and friction coefficient are experimentally estimated in the multiperforated region. Depth jet penetrations and film cooling thickness correlations are elaborated. Finally, all experimental results will be used to evaluate and validate future codes needed to simulate flows over multiperforated walls
Trouillet, Philippe. "Spectroscopie d'absorption appliquée à l'étude de la formation des oxydes d'azote dans une chambre de combustion à volume constant." Poitiers, 2000. http://www.theses.fr/2000POIT2253.
Devroe, Sebastien. "Etude de la combustion du charbon pulvérisé et de la formation des oxydes d'azote dans les grands foyers à chauffe tangentielle." Valenciennes, 1999. https://ged.uphf.fr/nuxeo/site/esupversions/b6ef6d88-6f13-449b-93ef-c890860834a6.
This work presents a study of combustion and NOx formation is tangentially boiler plant. It’s developed with Alstom-energy and ADEME’s support. The bibliography shows the importance of the turbulent flow simulation for a good prediction of combustion. And so, the study of the flow is uncoupled from the combustion. So in first, two cold scale models are studied. One represents totally a 600 MWe tangentially boiler unit (scale 1/20), the second one simulates a tangentially burner with square coaxial injectors. The measurements are compared with different turbulent models available in finite volume computer program Fluent. A specific flow at the nozzle of the burner named “snake’s tongue” was putted in light. In second part, the reacting flows in 3 tangentially fired boilers (1 natural gas, 2 pulverized coal) are presented. The calculated results are compared with furnaces observations. Finally, NOx are calculated for the three furnaces and different firing configurations. Thermal NOx are validated with the natural gas results. After an adjustment of the Fuel-NOx model, the calculations are in good agreement for the two furnaces and different loads with measurements