Tesi sul tema "Véhicules automobiles – Simulation, Méthodes de"
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Crauser, Jean-Pierre. "Méthodologie statistique pour l'étude des cinématiques et des consommations de véhicules légers". Montpellier 2, 1988. http://www.theses.fr/1988MON20162.
Testo completoLaliberté, Mathieu. "Modélisation et simulation d'un véhicule servant à l'étude de l'arrimage direct dans le transport d'équipements hors normes". Thesis, Université Laval, 2004. http://www.theses.ulaval.ca/2004/22068/22068.pdf.
Testo completoHernández-Gress, Neil. "Système de diagnostic par réseaux de neurones et statistiques : application à la détection d'hypovigilance du conducteur automobile". Toulouse, INPT, 1998. http://www.theses.fr/1998INPT042H.
Testo completoMonet, Descombey Julien. "Modélisation numérique de multicouches poroélastiques pour une application automobile". Compiègne, 2009. http://www.theses.fr/2009COMP1811.
Testo completoThe present report is in line with an industrial thesis supported by the Roberval Laboratory of the University of Technology of Compiegne in partnership with the French car manufacturer Renault S. A. This thesis aims to develop, in an industrial environment, some methodologies intended for the improvement of the prediction of vibroacoustic calculations on large size coupled fluid-structure systems including poroelastic materials using commercial finite elements software especially dedicated for this purpose to perform the calculations. Acoustic and vibratory comfort within a passenger car is a very important field of research for the automotive industry, so much so that the awaited benefits are important in terms of sales. Because of a policy of reducing the number of prototypes, there has been strong interest from carmakers for numerical simulations for several years now. Moreover, recent upheavals (petroleum price, governmental penalties for polluting vehicles, economic crisis…) have radically changed customer behavior who now focus more on cheap, cleaner and more sober vehicles. The automotive industry has to adapt to this new demand by reducing vehicle weight, which makes it possible to decrease consumption and thus the polluting emissions. Soundproofing insulators are particularly targeted and new, more complex, solutions are proposed for testing. Numerical tools are now use to validate, even optimize, these new generations of insulators. The work presented in this thesis presents three research orientations: the finite elements modeling of these acoustical insulators made mainly of poroelastic materials, the use of commercial software as a computer aided design tool and the deployment of an improvement process for the numerical models while respecting the constraints inherent to a complex product developed in a rapidly changing industrial environment
Chabot, Franck. "Contribution à la conception d'un entraînement basé sur une machine à aimants permanents fonctionnant sans capteur sur une large plage de vitesse : application au véhicule électrique". Toulouse, INPT, 2000. http://www.theses.fr/2000INPT006H.
Testo completoAccari, Elie. "Contribution à la modélisation de comportement dynamique de véhicule par réseaux multicouches". Littoral, 2005. http://www.theses.fr/2005DUNK0134.
Testo completoOne of the major concerns of manufacturers is the embedding of intelligence in the vehicle controller boards, in order to assist the driver in his maneuvers, to add comforts and increase security. This work is a contribution to the diagnosis of the dynamic behaviour of automotive vehicles by neural network approach. The goal is to detect any dynamic abnormal behaviour or dangerous situation and to inform rapidly the pilot in order to return to a normal security domain. Usually, security systems must be fast and have reduced false and non detection error rates. The vehicle security state is obtained thanks to an online estimation of some important variables such as vertical reaction, yaw rate and wheel slip. Feedforward networks such as MLP and RBF networks are used for this purpose. In order to generate the training samples data-bases essential for the neural network estimators, we create slalom and velocity profile maneuvers on dry and wet roads. We validate the results on a double lane-profile on various adherence road types
Golay, Francis. "Caractérisation de l'émission acoustique des véhicules étendus par des sources ponctuelles équivalentes". Le Mans, 2010. https://tel.archives-ouvertes.fr/tel-00853308.
Testo completoKhoury, Elias. "Modélisation de la durée de vie résiduelle et maintenance prédictive : application à des véhicules industriels". Troyes, 2012. http://www.theses.fr/2012TROY0027.
Testo completoMaintenance has become in many fields such as the automotive field, a very important aspect due mostly to its economic dimension. In this context, we are interested in improving maintenance decision making in order to reduce its costs mainly. We focus specifically on the predictive maintenance approach using the residual useful lifetime (RUL) as a tool for decision support. The RUL integrates information about the state of a system and its environment in the past, present and future (prediction). At first, we consider degradation based failure models. We study and develop several models that can describe different behaviours of degradation and failure mechanisms. In particular we consider a case study on engine oil. For these different models, we propose methods to estimate the distribution of the RUL conditionally to the state of the system and its environment. Subsequently, we propose predictive maintenance strategies in several configurations and we show how the RUL can be used in decision making. The conducted studies show the benefit of using the RUL and allow us to quantify the resulting gain depending on the considered case and the way the RUL is used
Damon, Pierre-Marie. "Estimation pour le développement de systèmes d'aide à la conduite des véhicules à deux-roues motorisés". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLE034/document.
Testo completoThe road accident investigations are unanimous: Powered Two-Wheeled Vehicles (P2WV) users are the most vulnerable on the road. In France, for a travelled kilometer, a P2WV rider has 24 times more risk to be killed than a car driver. In addition to being "naked" vehicles highly exposed to dangers, P2WV are naturally unstable with a precarious stability. That is why vehicle loss of control is clearly identified as a recurring problem into accident causation. By analogy with the driving assistance systems developed for cars (ABS, ESP, etc.), most of these accidents could be avoided with solutions dedicated to P2WV.This PhD takes place in this context and proposed original estimation algorithms. Indeed, some P2WV dynamic information, necessary for detecting risk situations, are not measurable or they require the use of costly sensors. For both technical or economic reasons, the use of observation techniques turns out to be an adequate solution in the development of P2WV riding assistance systems. Such techniques allow to estimate the vehicle dynamics while reducing the number of sensors and overcoming the unmeasurability of some dynamics states.A first part of my work is dedicated to model-based observers. In this context, an unknown input observer, a non-linear Luenberger observer and an algebraic observer were proposed. Whereas, the second part deals with the estimation based on visual perception techniques. In this last, a first algorithm was proposed to estimate the P2WV position on the road while predicting the road geometry. Then, an extension of this work was developed to reconstruct the P2WV roll angle using only images. Finally, a vision-based risk function was studied to characterize the P2WV steering behavior.All along this manuscript, the effectiveness of the proposed solutions were demonstrated through validations with the advanced simulator BikeSim framework or on experimental data
Hamdad, Hichem. "Recherche d'une description optimum des sources et systèmes vibroacoustiques pour la simulation du bruit de passage des véhicules automobiles". Thesis, Le Mans, 2018. http://www.theses.fr/2018LEMA1032/document.
Testo completoCurrently, to put a vehicle on market, car manufacturers must comply to a certification test of exterior noise. The regulation of the United Nations Economic Commission for Europe, ECE R51-03, specifies permissible levels a rolling motor vehicle can emit. This regulation is applied since July 1st, 2016, to replace the old regulation ECE R51-02 (test method change and tightening of permissible levels). The drastic reduction in noise levels will be done in 3 steps: from 74 dB (A) under the old regulation to 68 dB (A) in 2024. Therefore, manufacturers as well as their suppliers will face a great challenge to achieve this goal. The objective of this thesis is to develop an aid to the modeling of the pass-by noise of a vehicle, as called for in regulatory testing. The goal is to predict and evaluate accurately the noise emissions earlier in the vehicle development cycle, i.e. before the industrialization stage. We must then seek a trade-off between accuracy of estimates, sensitivity to parameters, robustness of the method and numerical efficiency
Codani, Paul. "Integration des véhicules électriques dans les réseaux électriques : Modèles d’affaire et contraintes techniques pour constructeurs automobiles". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC073/document.
Testo completoElectric vehicles (EVs) penetration has been rapidly increasing during the last few years. If not managed properly, the charging process of EVs could jeopardize electric grid operations. On the other hand, Grid Integrated Vehicles (GIVs), i.e. vehicles whose charging and discharging patterns are smartly controlled, could turn into valuable assets for the electrical grids as distributed storage units.In this thesis, GIVs are studied from a technical, regulatory, and economics perspectives. First, the general framework for a smart grid integration of EVs is reviewed: application areas and benchmark scenarios are described, the main actors are listed, and the most important challenges are analyzed.Then, the emphasis is put on system wide services, and more particularly on frequency control mechanisms. The regulatory conditions enabling the participation of GIV fleets to this service are studied based on an intensive survey of existing transmission system operator rules. Several economics and technical simulations are performed for various market designs.Then, local grid services are investigated. A representative eco-district is modeled, considering various consumption units and distributed generation. A local energy management system is proposed; it is responsible for controlling the charging / discharging patterns of the GIVs which are located in the district in order to mitigate the overloading conditions of the eco-district transformer. Economic consequences are derived from this technical analysis.At last, some experimental results are presented. They show the behavior of two GIVs, including one with bidirectional capabilities. The experimental proof of concepts confirm the theoretical abilities of GIVs: they are very fast responding units (even considering the complete required IT architecture) and are able to follow grid signals very accurately
Ricot, Denis. "Simulation numérique d'un écoulement affleurant une cavité par la méthode Boltzmann sur réseau et application au toit ouvrant de véhicules automobiles". Ecully, Ecole centrale de Lyon, 2002. http://bibli.ec-lyon.fr/exl-doc/TH_T1909_dricot.pdf.
Testo completoThe industrial objective of this study is the prediction of sunroof buffeting. Firstly, an analytical model found in literature is modified and validated. For the numerical approach, the possibility to use the Lattice Boltzmann Method (LBM) for aeroacoustics simulations is studied. A two-dimensional solver is developed. A selective filter is added and a hybrid non-reflecting boundary condition is proposed. The LBM is a low-dissipative scheme : it is therefore possible to calculate simultaneously the aerodynamic and acoustic fluctuations of the flow. The numerical dispersion of the acoustic waves is also investigated. A direct simulation of the noise radiated by the flow over a rectangular cavity is presented. The LBM commercial code PowerFLOW is used for industrial simulations. The dissipation associated with the turbulence model is studied. The self-sustained oscillation of the flow past the Helmholtz cavity (Nelson, 1981) is computed in 2D and 3D
Beck, Léon. "Modélisation et caractérisation de l'endommagement jusqu'à la rupture de l'assemblage structurel soudé par points". Electronic Thesis or Diss., Reims, 2023. http://www.theses.fr/2023REIMS053.
Testo completoIn the automotive industry, the demand for complex and innovative products by customers is growing, which presents development challenges. Simulation allows testing of vehicle structures and components before physical construction, saving time and resources. This innovation allows the automotive industry to advance rapidly and push its boundaries. Mercedes-Benz is a leader in designing durable vehicles. An important part of car design involves digitally modelling the connections between metal sheets in the body structure, which is mainly done through spot welds. The number of spot welds varies from 3000 to more than 5000. Precise spot welds modelling allows accurate sizing of the sheets and spot welds in the early stages, resulting in time and cost savings in a vehicle’s design phase.The latest technical innovations in the simulation and assembly of sheet metal consider various thicknesses and types of materials. Up to day, the company's current model does not include such improvements in the evaluation of spot weld strength. The objective of the present work is, therefore, to develop a better model. The goal is to simulate the robustness of spot welds assemblies, while ascertaining their capacity to endure stresses and calculating failure.A first study has been carried out to explore the various spot weld models used in industry. Numerous models can be classified according to their geometric representations, in particular circular, square and linear models. Each of those representations has its own advantages and disadvantages. The models based on a circular representation stand out when it comes to very precise models. However, their complex representation makes them difficult to integrate into a body-in-white. The two other representations particularly caught our attention: one using hexahedral elements with a specific material map and, respectively, one using bar-type elements with a dedicated search zone for simple integration into the assembly. These two representations present advantages and disadvantages, particularly in terms of independence from the mesh and mechanical behaviour.The idea of this work is to merge the advantages from both these representations A cohesive type element with a hexahedral shape based on the use of 3D Timoshenko beam type formulation defining the height of the weld zone. The developments were carried out on ABAQUS. This method allowed us to obtain an elastic model of our structure to be built up from the four edges, as well as a function for measuring the failure of the spot weld.To calibrate this new element, several test cases have been identified and simulated, including KSII, shear and peel tests. These series of tests aimed to verify the adaptation of the element to configurations of materials and thicknesses. Further simulations with varying mesh sizes set in evidence a phenomenon of mesh dependency, as in the models previously analysed. Therefore, a solution has been developed to include a zone of shell elements around our new element, which reduces the influence of the mesh.This latter process allowed us to calculate our hybrid element on different body-in-whites to validate our model on complex structures. The conducted simulations provided a good representation of reality. Differences are still noticeable in places, which can be explained by the fact that the material map developed with the hybrid model has not been calibrated for all possible combinations.This research represents a notable step forward in spot weld modelling, with promising results for a further application in [the company’s model?]. The creation of a hybrid model that can adapt to different mesh sizes and controls all degrees of freedom is a substantial achievement. Nonetheless, the precision and robustness of spot weld behaviour modelling may be further enhanced for considering an industrial application
Guelmbaye, Ngarsandje. "Prévision de la demande d'essence au Canada". Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25910.
Testo completoTagne, Fokam Gilles. "Commande et planification de trajectoires pour la navigation de véhicules autonomes". Thesis, Compiègne, 2014. http://www.theses.fr/2014COMP2004/document.
Testo completoMy research focuses on trajectory planning and control of autonomous vehicles. This work is a part of an extremely ambitious project launched by the Heudiasyc laboratory about autonomous driving at high speed (longitudinal speed greater to 5m/s ~= 18 km/h). With regard to the control of autonomous vehicles at high speed, a lateral controler using higher-order sliding mode control is proposed. Given the implicit similarity between the sliding mode and the principle of immersion and invariance, two controllers using the principle of immersion and invariance have been subsequently proposed in order to improve the performance with respect to the sliding mode. The development of these new controllers shows very strong robust stability which leads us to study the intrinsic properties of the system. A study of the passivity properties of the system is also crried out, showing some interesting characteristics of the system. Hence, a robust passivity-based controller has been developed. Regarding the navigation, we have developed two navigation algorithms based on the tentacles method. Subsequently, a feasibility study of trajectory generation strategies for high speed driving is conducted. The outcome of the simulation proved that the algorithms gave out good results with respect to the expected ogjectives of obstacle avoidance and global reference path following. Control and motion planning algorithms developed were validated offline by simulation with real data. They have been also tested on a realistic simulator
Poisson, Céline. "Concevoir pour le développement de la conduite automobile : contribution pour la compréhension de l’activité et des genèses instrumentales des sujets et du véhicule autonome". Thesis, Paris 8, 2019. http://www.theses.fr/2019PA080061.
Testo completoThe development of the autonomous vehicle is at the heart of current industrial and political concerns: either economically, in terms of road safety, or for the development of sustainable forms of mobility. Since the launch of the Google Car in 2010 - a hallmark moment for the autonomous vehicle innovation - many car manufacturers, original equipment manufacturers, and research institutes have began to work on the subject. As a result, more and more research projects are emerging, often supported internationally by government authorities. It is in this context that our research has been conducted, funded by VEDECOM Institute.The autonomous vehicle whose control, partial or total, is managed by a computer. Our goal is to understand and document driver activity in a fully autonomous vehicle over a specified period. However, this type of vehicle is not yet on the market, and it is therefore impossible to observe its use in real-life situations. To overcome this paradox, we studied reference situations (assisted driving), and simulated situations (simulator and track).Based on the principles of the instrumental approach and the capable subject, we have developed knowledge on instrumental geneses related to the introduction of an autonomous vehicle, with an aim to provide perspectives for anthropocentric and developmental design of this technical device
Mousset, Stéphane. "Estimation de la vitesse axiale à partir d'une séquence réelle d'images stéréoscopiques". Rouen, 1997. http://www.theses.fr/1997ROUES048.
Testo completoChemineau, Léonard. "Développement d'une méthode d'éco-conception basée sur la modélisation et l'évaluation des filières de valorisation : application au secteur automobile". Phd thesis, Paris, ENSAM, 2011. http://www.theses.fr/2010ENAMA012.
Testo completoCar design is increasingly constrained by environmental and economic issues and regulation. For manufacturers, the 2000/53/CE and 2005/64/CE European directives impose vehicle effective recovery, as well as recoverability rates for new cars, and proof that recovery is performed with reliable technologies. Moreover, motor vehicles are effectively treated more than 13 years after a potential eco-design decision. Existing and prospective path knowledge is then obviously very important to make the right design choices. This paper proposes a new modelling method based on paths technical and economic reliability, treatment cost and final products value conservation assessment, capable of providing designers with eco-design generic advices, and integrated recoverability assessment tool, without recovery expert knowledge. The basic modelling object is the 'Flow', assessed according to technical and economic parameters. The proposed method enables flow linking through paths and trees, and makes it possible to produce eco-design specifications. Case studies are performed on automotive parts, and four possible eco-design approaches are studied. The proposed method could also be applied outside of the automotive world
Baffet, Guillaume. "Développement et validation expérimentale d’observateurs des forces du contact pneumatique/chaussée d’une automobile". Compiègne, 2007. http://www.theses.fr/2007COMP1695.
Testo completoEstimation of vehicle-dynamic variables is essential for safety enhancement, in particular for braking and trajectory-control systems. The aim of this thesis is to develop state observers for the estimation of variables linked to tire-road friction. Different estimation methods are proposed in order to reconstruct tire-road forces and vehicle sideslip angle. The estimation algorithms are constructed so as to be functional in critical driving situations, notably for weak lateral accelerations and road friction changes. In addition to estimation methods, this thesis presents a substantial number of observer evaluations, performed in simulations and in experiments. The estimation process was integrated in an experimental vehicle, and was tested in real time, particularly in relation to wheel force measurements
Chemineau, Léonard. "Développement d'une méthode d'éco-conception basée sur la modélisation et l'évaluation des filières de valorisation : application au secteur automobile". Phd thesis, Paris, ENSAM, 2011. http://pastel.archives-ouvertes.fr/pastel-00604000.
Testo completoRibes, Charles. "Caractérisation par méthode optique des débordements d'eau de pluie sur les vitres latérales d'un véhicule automobile". Poitiers, 2008. http://www.theses.fr/2008POIT2289.
Testo completoOverflow of rain water on side windows of a car leads to a degradation of the driving security and comfort. A lot of wind tunnel studies are necessary to avoid this phenomenon, and further developments of numerical simulation tools are still needed. In this thesis, we study the way rain water flows over the windshield, the A-pillar and the side windows of simplified bluff bodies and realistic cars through wind tunnel tests and numerical simulations. An optical measurement method for liquid film thickness based on induced fluorescence and an experimental protocol for full-scale wind tunnel tests were developed. An experimental data base is build with strictly controlled boundary conditions to study the most important parameters: - overflow zone's geometry (windshield gutter and A-pillar's shape) and its influence on local aerodynamic field and on water draining, - car's velocity, - water fluxes linked to rain intensity, - surface effects influence. A combined analysis of those results with aerodynamic simulations brings to light the main mechanisms of overflow (flow in the gutter and on the A-pillar) and water paths on the side windows. The comparison of the experimental data with results from a one equation surface film model enables to underline the lack of efficiency of this kind of modeling. Then ways of improvement of the simulation process are suggested
Yassine, Mohamad. "Multi-physics modeling of the intake line of an internal combustion engine". Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0005.
Testo completoThe competition among carmakers to introduce the most innovative solutions is growing day by day. Since few years, simulation is being used widely in automotive industries. Concerning the study of gas dynamics and pressure wave’s propagation in the intake system of an internal combustion engine, whichhave a significant effect on engine behavior, a precise modelling is needed in order to obtain good results. The main objective of the methodology presented in this PhD thesis, is to shorten the simulation time in order to study the behavior of an internal combustion engine, while conserving a good accuracy level. The pressure waves are studied using frequency approach. This latter is based on a transfer function, which links the relative pressure and the air mass flow rate upstream the intake valve. A multi-physics coupling model in the simulation code was established. The model validation was conducted using precision criterion on volumetric efficiency and on instantaneous pressure upstream of the intake valve. The results showed good accuracy level. In terms of computational time, the transfer function methodology is faster than the native one-dimensional non-linear code. This methodology can be an alternative method for modeling the intake geometry of an IC engine
Ketfi-Cherif, Ahmed. "Modélisation mathématique d'organes de véhicules automobiles à basse consommation : applications en simulation, estimation et commande". Paris 9, 1999. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=1999PA090037.
Testo completoDang, Thanh Thuy Van. "Méthodes pour l'analyse de cycle de vie des batteries lithium-ion des véhicules électriques". Paris, ENMP, 2011. http://www.theses.fr/2011ENMP0051.
Testo completoA framework enabling an application of Life Cycle Assessment approach to various technologies of Lithium-ion Electric Vehicles batteries is created. It encompasses all the life cycle of the product (Manufacturing – Use – End of Life). More precisely, a specific LCA database for Li-ion batteries is constructed and batteries life cycle is successfully modeled. Others difficulties are discussed and solved during this works, such as the choice of batteries functional unit, system modularity, uncertainties of the Use phase and of batteries' lifetime, allocation rules for batteries End of Life… A sensibility analysis is carried out and shows that LCA results strongly depend on chosen data and scenarios. Main conclusions obtained from the base case of our studies are: - Climate change potential of a battery is about 10 - 15 kg CO2 éq/kg of batteries. This amount takes into account the manufacturing and the end of life. Others environmental impacts are also quantified (regional impacts such as acidification, eutrophisation; human toxicity and ecotoxicity…). - Batteries LCA results are sensitive regarding to the choice of its materials, of the manufacturing processes and of the geographic parameters. - Materials recovery during the End of Life phase leads to environmental benefit for the global impacts of the batteries. However, it depends on the recycling process (pyrometallurgical and/or hydrometallurgical), as well as on the nature of recovered materials. - Batteries leasing scenario can help minimizing environmental impacts of Electric Vehicles park. In order to facilitate eco-conception of Li-ion batteries, a simplified LCA model is created, which reduces times and costs of future LCA studies while ensuring the same accuracy
Ribière-Tharaud, Nicolas. "Amélioration des méthodes de qualification des véhicules automobiles en CEM : applications aux faisceaux de câbles". Paris 11, 2001. http://www.theses.fr/2001PA112213.
Testo completoCharif, Omar. "Modelling and simulating individual's mobility : case study of Luxembourg and its greater region". Electronic Thesis or Diss., Compiègne, 2013. http://www.theses.fr/2013COMP2130.
Testo completoIn the last century, transport and in particular the use of private cars has emerged as a major source of CO2 emissions (second behinf energy production). Several cities in the world have put in place strategies to deal with this problem and to reduce its adverse enviromental impacts. Some strategies could not achieve their objectives, and had negative reactions from individuals. The ail of this PhD thesis is to propose a methodology and a platform for modelling and simulating people mobility systems. The developed plat form is, then, used to implement land use and transportation scenarios and strategies in a virtual world to study their impact on human behavior in terms of mobility. To develop this platform, we propose a hybrid model, combining cellular automata and multi-agent systems, capable of handling the complexity of the mobility system able to present it at various spatial ans temporal scales
El, Khoury Georges. "Etude et simulation de systèmes de climatisation adaptés aux véhicules hybrides". Paris, ENMP, 2005. http://www.theses.fr/2005ENMP1357.
Testo completoThis dissertation aims at analyzing the impact of the air-conditioning system on hybrid vehicles by using data of the additional fuel consumption due to MAC operation. Those data are obtained on roll benches (UTAC and CRF) and test benches (CEP and VALEO) dedicated to mobile air conditioning systems. Tests on Prius I show that energy savigs due to hybridization are compromised when the air conditioning system is driven by a mechanical compressor, which requires operation of the engine when the vehicle is stopped. Electrical and hybrid compressors have been tested. Air conditioning loops integrating those compressors are simulated via a set of MACLIB routines developed during this thesis in Matlab/Simulink language. MACLIB is then integrated in the ADVISOR simulator in order to evaluate additional fuel consumptions of the different air conditioning systems installed on a reference hybrid vehicle. Some simulations have been validated by tests performed on roll benches at UTAC, on the Prius II equipped with an electric compressor. Once MACLIB has been validated, comparative analyses of air conditioning systems either mechanical, or electrical, or hybrid (mechanical/electrical) installed on the reference vehicle, have been performed. Those analyses end by the evaluation of the annual additional fuel consumption of mobile air conditioning systems operating under two European climatic conditions
Esteves, Nicolas. "Modélisation thermique et aéraulique des alternateurs pour les simulations de l’espace sous capot d’un véhicule automobile". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI124.
Testo completoThe objective of the thesis is to create a thermal model of an alternator, with a quickly time run. This model will integrate the influence of the alternator inside an under-hood simulation. A simplify model able to simulate the aerodynamic and thermal behaviour has developed. It use a nodal approach to simulate the aerodynamic and thermal behaviour. Different algorithms and an user’s interface able to a quickly set up and a automatically implementation. Indeed, the nodal, approach was realized automatically by the model, the user inform the dimensions of the alternator, the materials characteristics and the thermal losses. Thanks to we have a model that use with any automobile alternator. The aerodynamic of the alternator is simulate with convection coefficient via the nodal approach. These coefficients are estimated with correlations based on Reynolds of the flow. The CFD simulation of the alternator identified these correlations. The CFD model has been validate with an aerodynamics tests. The model is checked and validate by thermal tests. It has an average error lower than 10% and work to any regime of the use. The time run is equal to 2 minutes. The modal has been integrate inside an under-hood simulation. A coupling methodology has been developed to allow the integration of the data, like the temperatures and the flowrate was estimate by the simplify model, inside an under-hood simulation. The under-hood simulation modelling the aerodynamic and thermal behaviour of the engine compartment. Therefore, the coupling methodology allow integrating the aerodynamic and thermal influence of the alternator inside the compartment. The work is actually in progress inside the numerical processes of the PSA group. Many perspectives are studied, to use the model on other under-hood elements, or other electric machine, like the electric engines used inside the hybrid vehicles
Charif, Omar. "Modelling and simulating individual's mobility : case study of Luxembourg and its greater region". Thesis, Compiègne, 2013. http://www.theses.fr/2013COMP2130.
Testo completoIn the last century, transport and in particular the use of private cars has emerged as a major source of CO2 emissions (second behinf energy production). Several cities in the world have put in place strategies to deal with this problem and to reduce its adverse enviromental impacts. Some strategies could not achieve their objectives, and had negative reactions from individuals. The ail of this PhD thesis is to propose a methodology and a platform for modelling and simulating people mobility systems. The developed plat form is, then, used to implement land use and transportation scenarios and strategies in a virtual world to study their impact on human behavior in terms of mobility. To develop this platform, we propose a hybrid model, combining cellular automata and multi-agent systems, capable of handling the complexity of the mobility system able to present it at various spatial ans temporal scales
Chateauroux, Élodie. "Analyse du mouvement d'accessibilité au poste de conduite d'une automobile en vue de la simulation : cas particulier des personnes âgées". Lyon, INSA, 2009. http://theses.insa-lyon.fr/publication/2009ISAL0037/these.pdf.
Testo completoThis study takes place in the context of Digital Human models used to test the ergonomics of environments such as automotives in the earliest stages of the design process. Yet, these tools do not take into account the aging of the population. The car ingress and egress motions are particularly problematic for seniors. This thesis aims at analysing car accessibly movements of elderly people in order to 1/ better understand their difficulties and 2/ simulate these motions using a digital human model. Eighteen elderly and 7 young subjects participated in the experiment. Ingress and egress motions were captured for four types of vehicle and discomfort ratings were collected by a questionnaire. As age effects differ from one person to another, the functional capacities were measured using clinical tests to draw a portrait of the abilities of each elderly subject. Results of these tests are used to define 3 groups of people: those who have a functional problem, those with “mediocre” capacities and those who have good capacities. Ingress and egress motions are analysed through the interaction between the subject and the environment in order to define the constraints linked to vehicle design. Two major strategies have been observed for the ingress and egress movements. The strategies “Sit First” and “Two Legs Out” are used by people with functional problems. The strategies “Right Leg First” and “Left Leg First” are the most observed ingress and egress strategies, regardless of functional capacities. These movements are decomposed into phases for which sub-strategies are defined. The interactions between the hands and the environmental seem to play an important role. Compensation mechanisms are observed in the movements of persons with functional problems. The discomfort questionnaires show that elderly subjects face more problems when exiting than when entering a car. Discomfort ratings are influenced by the functional abilities of subjects but the results are very heterogeneous. An explanation would be that these ratings also reflect the preferences of subjects in terms of car accessibility. An external examiner would then better assess the difficulties of elderly people. The captured movements are structured in databases in order to simulate the accessibility movements of elderly using the RPx software
Keita, Namamoudou Sidiki. "Étude de la dispersion de nanoparticules dans le sillage d’obstacles : cas d’un véhicule automobile". Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0205.
Testo completoIn this thesis, the study of the interactions between ultrafine particles emitted by the exhaust pipes and the wake flow generated by the emitting vehicle was carried out mainly using a numerical approach. An experimental campaign was conducted for validation purpose. The goal of the thesis is to understand the impact of exhaust particles on the surrounding environment on both the pedestrian and the passengers of the following vehicles. For this purpose, the fluid flow was resolved with an Eulerian type URANS model (Unsteady Reynolds Average Navier-Stokes) combined to the Lagrangian approach for the nanoparticles trajectories calculation. This thesis is conducted simultaneously with a collaborative project funded by ADEME (CAPTIHV) whose purpose is to assess the air quality of automotive car cabins, and particulate infiltration from the surrounding traffic in particular of ultrafine particles. The study of the dispersion of fine particles in turbulent flows requires a fine analysis of the turbulent structures that develop in such flows. Our numerical study therefore consisted, first, in analyzing this dispersion in the case of a classic wake flow downstream of a cylinder. This enabled us to characterize the interaction of solid carbon nanoparticles with vortical structures evaluating at the same time the impact of turbulence and Brownian diffusion. This allowed determining the influence of the main mechanisms influencing nanoparticles dispersion. In a second step, we replaced the cylinder configuration by a simplified geometry of a motor vehicle, Ahmed body configuration. Therefore, simulations with and without of particles presence have been conducted and have allowed to highlight the swirls structures and to characterize the particles dispersion through particle concentration profiles and the particles dispersion coefficients. The results of these simulations allowed us determining the important mechanisms / forces that can influence the dispersion of such particles in the wake of a ground vehicle; this facilitated the implementation and analysis of relatively more complex simulations of the aerodynamics of the square back Ahmed body in the presence of nanoparticles simulating soot from the exhaust gases. The interactions of ultrafine particles with vortical structures appearing in the wake of vehicles were evaluated from concentration profiles and transverse dispersion coefficients. The final step was a wind tunnel experimental campaign that allowed us to characterize the average and turbulent velocity fields as well as the particle concentration fields downstream of the vehicle to validate the numerical results
Keita, Namamoudou Sidiki. "Étude de la dispersion de nanoparticules dans le sillage d’obstacles : cas d’un véhicule automobile". Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0205/document.
Testo completoIn this thesis, the study of the interactions between ultrafine particles emitted by the exhaust pipes and the wake flow generated by the emitting vehicle was carried out mainly using a numerical approach. An experimental campaign was conducted for validation purpose. The goal of the thesis is to understand the impact of exhaust particles on the surrounding environment on both the pedestrian and the passengers of the following vehicles. For this purpose, the fluid flow was resolved with an Eulerian type URANS model (Unsteady Reynolds Average Navier-Stokes) combined to the Lagrangian approach for the nanoparticles trajectories calculation. This thesis is conducted simultaneously with a collaborative project funded by ADEME (CAPTIHV) whose purpose is to assess the air quality of automotive car cabins, and particulate infiltration from the surrounding traffic in particular of ultrafine particles. The study of the dispersion of fine particles in turbulent flows requires a fine analysis of the turbulent structures that develop in such flows. Our numerical study therefore consisted, first, in analyzing this dispersion in the case of a classic wake flow downstream of a cylinder. This enabled us to characterize the interaction of solid carbon nanoparticles with vortical structures evaluating at the same time the impact of turbulence and Brownian diffusion. This allowed determining the influence of the main mechanisms influencing nanoparticles dispersion. In a second step, we replaced the cylinder configuration by a simplified geometry of a motor vehicle, Ahmed body configuration. Therefore, simulations with and without of particles presence have been conducted and have allowed to highlight the swirls structures and to characterize the particles dispersion through particle concentration profiles and the particles dispersion coefficients. The results of these simulations allowed us determining the important mechanisms / forces that can influence the dispersion of such particles in the wake of a ground vehicle; this facilitated the implementation and analysis of relatively more complex simulations of the aerodynamics of the square back Ahmed body in the presence of nanoparticles simulating soot from the exhaust gases. The interactions of ultrafine particles with vortical structures appearing in the wake of vehicles were evaluated from concentration profiles and transverse dispersion coefficients. The final step was a wind tunnel experimental campaign that allowed us to characterize the average and turbulent velocity fields as well as the particle concentration fields downstream of the vehicle to validate the numerical results
Lecocq, Pascal. "Simulation d'éclairage temps réel par des sources lumineuses mobiles et statiques : outils pour la simulation de conduite". Université de Marne-la-Vallée, 2001. http://www.theses.fr/2001MARN0122.
Testo completoBergman, Carl Magnus. "Développement de méthodes numériques pour des écoulements hypersoniques non visqueux autour d'engins spatiaux". Toulouse, INPT, 1990. http://www.theses.fr/1990INPT058H.
Testo completoEl, kadri Khadija. "Contribution à la conception d'un générateur hybride d'énergie électrique pour véhicule : modélisation, simulation, dimensionnement". Besançon, 2006. http://www.theses.fr/2006BESA2036.
Testo completoThe work detailed in this thesis is part of a research project conducting at L2ES lab and supported an industry grant from DGA. The ECCE project aims at designing a mobile platform for assessing the different components of an electrical power train. The proposed study defines and evaluates a system using two main power sources which are integrated in a high performance heavy vehicle. The description and validation of hybrid generator were done using the simulations and benchmarks included in the platform featuring 120 kW. To understand and analyze how the system operates we developed a multi-blocks tool that models a vehicle with a focus on the two power sources. A model of the different components of the power train has been first defined. Then, several simulations have been used with the goal to highlight certain phenomena such as resonance as well as coupling related problems of energy sources. A special attention has been given to the storage system consisting of a battery. Part of the experiment we conducted was dedicated to the battery. Our goal was to master the protocol we used and to identify the different attributes of the underlying model. For the development of any electrical system and with the objective to conform to safety standards and procedures related to the high voltage used in the vehicle, we gave a special attention to electrical hazards. Some enhancements have been made related to the different procedures that regulate the usages of high voltage and that describe the consequences in terms of protection of the human personnel and equipments
Bouron, Pascal. "Méthodes ensemblistes pour le diagnostic, l'estimation d'état et la fusion de données temporelles". Compiègne, 2002. http://www.theses.fr/2002COMP1395.
Testo completoSet-membership methods for diagnosis, state estimation and data fusion The works presented in this thesis constitute a contribution to the use of set-membership methods the state estimation and fault detection and isolation. These methods are used in the actual context of localisation and dynamic diagnosis of a vehicle. After describing the system used in the analysis and defining dynamical model, we expose an adaptation of the classical diagnosis method based on analytical redundancy in the context of a bounded-error modelisation of the noises. This method has been validated with real data coming froID our demonstrator. The second original aspect of this work is the utilization of set-membership methods for state estimation. It has led to the elaboration of alternative methods to improve the mn times of Sallie algorithms. Finally, the development of a syntaxical analysis module allowed us to easily process the methods based on constraint propagation. We have validated these methods with actual data for the localization, and with simulated data for the estimation of the drift. Moreover, a comparison of the accuracy of the estimation with the Extended Kalman Filtering has been realized
Jandaud, Pierre-Olivier. "Étude et optimisation aérothermique d'un alterno-démarreur". Thesis, Valenciennes, 2013. http://www.theses.fr/2013VALE0018/document.
Testo completoThe goal of this thesis is the aero-thermal study and optimization of a starter-alternator used in hybrid cars. This kind of machines being more powerful than a regular alternator, their cooling is critical. The machine is modeled using lumped method in steady state which uses networks of thermal conductances. The inputs for the model are obtained using correlations from bibliography for the convective heat transfers and three dimensional CFD for the flow rates inside the machine. The numerical results are validated by experimental results with PIV for the fluid results and a machine fitted with thermocouples for the thermal part. In the second part, the thermal code is coupled with an optimization algorithm to obtain an optimal geometry of the machine from a thermal point of view. The method chosen is Particle Swarm Optimization (PSO). The parameters are the sizes of the end-windings, the positions of the fans and the cross section of the rotor channels. For different objectives, different optimal geometries are obtained. The last part of this work aims at the multi-objectives optimization of a heat sink located at the back of the machine. The heat sink has to be thermally efficient but should not affect the flow. Different shapes of fins are also studied
Egot, Stéphane. "Intégration des équipements électroniques dans la modélisation de l'architecture électrique des véhicules automobiles : application à la prédiction de compatibilité électromagnétique dans les phases amont de la conception". Lille 1, 2005. http://www.theses.fr/2005LIL10151.
Testo completoThis thesis deals with the elaboration and the evaluation of an integration methodology of electronic equipment in the EMC modeling of the electrical architecture in the early design phase of a vehicle. The proposed approach is based on dissociating the equipment modeling into two complementary parts involving the car manufacturer and the elctronic supplier. The feasibility of this modeling technique primarily required ton characterize the interaction between the equipment and the car body. Besides, the different factors having an influence on the validity of the model were examined as well as its needed level of precision. The latter issue was considered by taking into account the globality of the system, especially the variability brought by the random bundling of the cable harness. Finally the proposed method was evaluated by comparing statistical measurement and simulation results obtained on a realistic electronic sub-system
Vérant, Jean-Luc. "Etude de méthodes numériques et de modèles physico-chimiques pour des écoulements hypersoniques réactifs : application aux véhicules spatiaux". Aix-Marseille 1, 1990. http://www.theses.fr/1990AIX11314.
Testo completoMeneroux, Yann. "Méthodes d'apprentissage statistique pour la détection de la signalisation routière à partir de véhicules traceurs". Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC2061.
Testo completoWith the democratization of connected devices equipped with GPS receivers, large quantities of vehicle trajectories become available, particularly via professional vehicle fleets, mobile navigation and collaborative driving applications. Recently, map inference techniques, aiming at deriving mapping information from these GPS tracks, have tended to complete or even replace traditional techniques. Initially restricted to the construction of road geometry, they are gradually being used to enrich existing networks, and in particular to build a digital database of road signs. Detailed and exhaustive knowledge of the infrastructure is an essential prerequisite in many areas : for network managers and decision-makers, for users with precise calculation of travel times, but also in the context of the autonomous vehicle, with the construction and updating of a high definition map providing in real time electronic horizons, which can supplement the system in the event of failures of the main sensors. In this context, statistical learning methods (e.g. Bayesian methods, random tree forests, neural networks,...) provide an interesting perspective and guarantee the adaptability of the approach to different use cases and the great variability of the data encountered in practice.In this thesis, we investigate the potential of this class of methods, for the automatic detection of traffic signals (mainly traffic lights), from a set of GPS speed profiles. First, we are working on an experimental, high-quality dataset, for which we compare the performances of several classifiers on classical image recognition approaches and on a functional approaches stemming from the field of signal processing, aggregating and decomposing speed profiles on a Haar wavelet basis whose coefficients are used as explanatory variables. The results obtained show the relevance of the functional approach, particularly when combined with the random forest algorithm, in terms of accuracy and computation time. The approach is then applied to other types of road signs.In a second part, we try to adapt the proposed method on the case of observational data for which we also try to estimate the position of the traffic lights by regression. The results show the sensitivity of the learning approach to the data noise and the difficulty of defining the spatial extent of individual instances on a complex road network. We are trying to solvethis second issue using global image approaches based on a segmentation by convolutional neural network, allowing us to avoid the definition of instances. Finally, we are experimenting an approach leveraging spatial autocorrelation of individual instances using the graph topology, by modeling the study area as a conditional Markov field. The results obtained show an improvement compared to the performance obtained with non-structured learning.This thesis work has also led to the development of original methods for pre-processing GPS trajectory data, in particular for filtering, debiaising coordinates and map-matching traces on a reference road network
Philippe, Christophe. "Méthodologie de modélisation et d'évaluation d'applications réparties temps réel sûres de fonctionnement : application, dans le domaine automobile, à l'électronique embarquée et à l'informatique manufacturière". Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL090N.
Testo completoAutomotive electronic embedded systems, and control systems of vehicle manufacturing, are characterised by hard constraints of time and of dependability. We are interested in this document to the introduction of communication networks in these applications, and propose a methodology to assess such applications. This methodology pro vides a modelling formalism and a framework for assessment methods. The first part of the document justifies our work. After giving some necessary definitions (chapter 1), applications in both domains (embedded systems and manufacturing computer systems) are characterised and synthesised (chapter 2). The second part of the document presents the modelling and assessment methodologies. The modelling formalism integrates the notions of Application Model, Architectures (Functional 'Architecture, Resource Architecture, Operational Architecture), and properties (Characteristics and Constraints). The framework is able to integrate methods of characterics evaluation, of constraints verification, or of application models comparison. The third part of the document describes through examples, the conception, the integration in the framework, and the use, of assessment methods. The chapter 4 presents some temporal valuation methods of communication profiles (mainly based on CAN and ASI networks). The chapter 5 shows dependability assessment methods (ordinal assessment of faults, failure assessment of communication profiles, assessment of fault tolerance solutions based on replication). The fourth part describes a software tool implementing the methodology (chapter 6), and its application in a case study (chapter 7)
Mahmoudi, Madjid. "Corrélation entre essais de CEM sur table et essais sur véhicules d' équipements pour automobiles". Paris 6, 2005. http://www.theses.fr/2005PA066438.
Testo completoAit, El Menceur Mohand Ouidir. "Modélisation, analyse et simulation du mouvement d'entrée dans des véhicules automobiles à géométrie variable : application aux mouvements d'entrée des personnes âgées et/ou ayant des déficiences motrices". Valenciennes, 2009. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/9af8c69a-6673-4f19-a631-11a69e374902.
Testo completoThe difficulty from which suffer elderly and/or disabled people when entering or exiting an automobile vehicle can lead them to never use it again. The car manufacturers are conscious of this fact and they are more and more interested in these growing elderly and/or disabled populations prone to locomotor apparatus disorders and in this complex gesture requiring a precise coordination of the human body articular movements. An alternative to understand and predict this movement is to use the digital simulation. Works completed in this thesis fall under this context and concern the kinematic simulation of the vehicle entering movement of a humanoid (constituted of a head, a trunk, a basin and lower limbs) in variably-dimensioned vehicles by using real data resulting from the experimentation. To solve this "complex" problem, we propose a three stage methodological procedure. A first stage carries on the constitution of a base of movements that we name "exploitable" movements which are issued from the experimentation carried out on two variably-dimensioned vehicles. These "exploitable" movements are the result of digital processing applied to the measured entry movements. These processing allow, among others, to adapt the measured joint articulation angles to the humanoid in order to avoid possible collisions with the cockpit which would not have been noted during the experiments. A second stage relates to the automatically analysis and identification of the vehicle entering movement strategies. This stage proceeds in four phases and it allows the identification of 2 entry movement strategies and 6 sub–strategies. A third stage, made up of 4 phases as well, uses the assets resulting from stages 1 and 2 to simulate an entry movement of a subject of the base adopting a given sub-strategy in another vehicle of different geometry. The simulation of the entry movement of the same subject in another vehicle concerns an inverse kinematics problem solved by constrained nonlinear programming. Simulations, implying elderly and/or having prostheses people, make it possible to validate the suggested procedure for the two entry strategies. In spite of the differences with the measured movements, the simulated movements are in conformity with the sub-strategies adopted by the subjects during the experiments. Furthermore, the realized simulations make it possible to explain partly the changes of strategy operated by some subjects, during the experiments, when shifting from one vehicle to another. Finally, simulations on fictitious vehicles show the limits of the developed simulation tool. This work opens several prospects for research as well concerning the improvement of simulation, by considering for example the intra-individual differences of subjects or the dynamics of the movement, as the development of new ergonomic indices in order to consider discomfort associated with the simulated movements
Gidel, Samuel. "Méthodes de détection et de suivi multi-piétons multi-capteurs embarquées sur un véhicule routier : application à un environnement urbain". Clermont-Ferrand 2, 2010. http://www.theses.fr/2010CLF22028.
Testo completoIbambe, Gatsinzi Martine. "Etudes des performances radiofréquences d'antennes 5,8 GHz intégrées sur des véhicules automobilesApplications sécuritaires et communications à courte portée". Paris 11, 2008. http://www.theses.fr/2008PA112179.
Testo completoEvolution in technology allows automotive manufacturers and suppliers to propose more and more embedded electronic systems to make driving safer and easier. However, the number of road victims is still high. In this context, a study of the integration of a pre-crash radar operating at 5. 8GHz has been launched by Renault. This system is based on low cost components and allows the activation of either automatic braking to avoid any crash or restraint systems in case of an impending collision. Besides, to reduce the number of integrated antennas on vehicles, other applications, such as smart keyless and vehicle to vehicle communication systems can use the same radar antenna. The main objective of the proposed research work is to study the integration of 5. 8 GHz antennas on vehicles. In particular, simulations are performed to investigate the integration on numerical prototypes to make up for problems posed by the late availability of car prototypes and the reduction of cost in industry. For this purpose, we focused on the 4 following topics: 1) Simulation at higher frequencies and measurement to evaluate integration effects on antenna radiation. 2) Analysis of wave propagation in vehicular environments to quantify and qualify propagation channel in the 5. 8 GHz frequency band. 3) Study of radar signal propagation. The goal is to develop a method for echo signal analysis of the radar prototype by modeling and simulating the antenna and different targets in road environments. 4) Evaluation of antenna integration and wave propagation at 24 GHz. We have presented a study of a second type of pre-crash radar currently under investigation
Goubel, Clément. "Modélisation d’essais de choc sur dispositifs de retenue de véhicules : Application aux dispositifs mixtes acier-bois". Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10333/document.
Testo completoIn France, one third of the people dying on the roads are killed after impacting against ahazard. In 90% of the reported cases, these accidents result from loss of control. VehicleRestraint Systems (VRS) are specially designed to restrain an errant vehicle and to limitimpact severity.Before being installed on the roadsides, these devices have to be crash-tested according tostandards in order to evaluate their safety and deflexion performances.Tolerances exist on impact parameters (vehicle, vehicle mass, impact speed, impact angle,impact point …) and material’s mechanical characteristic uncertainties have an effect towardsdevice performances and have to be taken into account during numerical simulations.Steel-wood structures present an additional numerical challenge due to wood heterogeneityand its sensibility to environment variables such as temperature and moisture content.In order to assess the effect of this variability toward safety performances, three point bendingdynamic experiments on structural samples are performed and modelled.Finally, a complete model of a vehicle restraint system is built and validated according to realcrash test results thanks to a parametric method. This method takes into account the variabilityof the parameters associated to the failure modes of the structure. Once validated the model isused to assess the effect of wood mechanical properties modifications due to environmentvariable variations
Nauleau, Florent. "Méthode des frontières immergées pour la simulation aux grandes échelles de véhicules de rentrée hypersoniques". Electronic Thesis or Diss., Bordeaux, 2023. http://www.theses.fr/2023BORD0477.
Testo completoThe aim of this thesis is to develop a simulation code for the design of atmospheric reentry vehicles. The code used is an immersed boundary code, which considerably reduces the time required to generate complex meshes. Several implementations within the code reduce computation time while increasing accuracy. The study of complex phenomena developing around simulated objects will be aided by topological analysis, helping in the choice of numerical method to be used. From a numerical point of view, the design of an atmospheric reentry vehicle for its aerothermal performance often relies on computational codes using averaged Navier-Stokes equations (RANS) and body-fitted structured meshes. These two technologies enable us to obtain an averaged representation of the phenomena in a reasonable time. However, the use of an averaged field implies less control over the maximum stresses that could be applied to the vehicle, and the generation of these body-fitted meshes is extremely time-consuming. From a visualization point of view, traditional analysis methods are based on flow geometry and field-averaged quantities. Due to high Mach and Reynolds numbers and the geometric complexity of flows, these methods are often pushed to the limits of their applicability, or even rendered obsolete for vortex segmentation and comparison. The aim of this thesis is to provide some answers to the above-mentioned numerical and scientific visualization concerns. To improve immersed boundary methods, new Riemann solvers and high-order reconstruction schemes such as TENO and WENO have been integrated within a Direct Numerical Simulation (DNS) code. To reduce the mesh cost of DNS simulations, the Wall-Adapting Local Eddy-Viscosity (WALE) subgrid-scale model has been implemented. This model able Large Eddy Simulation (LES) to be carried out. In these simulations, the larger vortices are computed and the smaller ones modeled. Boundary layer capture, i.e. aerodynamic and thermal effects at the vehicle wall, is investigated by proposing wall models for hypersonic flows. These wall models will make it possible to reduce the number of cells and thus the computational cost of modeling the boundary layer. Topological data analysis is a particularly interesting emerging approach to apprehend the quantity and complexity of data generated in aerodynamics. This field, born of computer science and applied mathematics, proposes to extract, measure and compare structural information hidden within large volumes of complex data. Based on projection and dimension reduction techniques, these approaches extract features from data that are difficult to identify in geometric space, and complement the functionalities of high-performance visualization software such as Paraview. Topological analysis protocols have been proposed to compare and validate the new Riemann solvers and high-order reconstructions implemented in this thesis. These protocols have been applied to 2D turbulence, and have enabled us to select pairs of Riemann solvers and high-order reconstructions to reduce the computational cost of simulations while maintaining good accuracy in describing the phenomena studied
Amalric, Joël. "Contribution à l'étude de la planification de mission spatiale : développement du système expert SERVO pour la planification des missions de rendez-vous de l'avion spatial Hermès". Toulouse, INPT, 1991. http://www.theses.fr/1991INPT050H.
Testo completoCastric, Sébastien. "Méthodes de recalage de modèles et application aux émissions des moteurs diesel". Compiègne, 2007. http://www.theses.fr/2007COMP1696.
Testo completoSince some decades, European vehicles are subjected to normative laws about pollutant emissions. To face these constraints, car manufacturers have used more and more complex technologies especially for diesel engine cars. This situation has led to a complexification of engine tuning since the numbers of setting parameters has increased too. The present research work was made for the car manufacturer Renault SAS. It aims at proposing methods that allow readjusting models and applications over pollutant models of diesel engine. Renault decided to use techniques of design of experiments, modelling and optimization to solve the problem of diesel engine tuning for emissions. Even if this approach gave good results, it has some drawbacks. The tuning process is composed of loops. Each loop involves hardware changes in the engine. In this case, the model representing the engine’s behaviour, which is a LOLIMOT model, is not valid anymore. Considering that it is not possible to completely rebuild a model, a question appears: “How is it possible to readjust the model after an hardware change by doing as few tests as possible?” This PhD proposes some ways to solve this problem. The first one consists in using the bayesian theory. By using the initial model as an a priori, we created an algorithm permitting to readjust LOLIMOT models. In addition, we proposed a method derived from the first one, and, which aims at using the tuner knowledge about the engine as a prior knowledge. We tested our methods by simulation and owing to tests made on a 2L diesel engine, which was subjected to different hardware changes. In a second time, we considered that even if the Bayesian theory is able to take into account some knowledge, it does not take into account the hardware change characteristics. Thus, we decided to create a new model integrating physical parameters, like, for example, the number of holes in the injectors. We developed a model of diesel combustion. It simulates the evolution of thermodynamic variables inside the combustion chamber even for the multi injection case. Next, we adapted models of pollutants using these variables as inputs. We tested the whole model on prediction of cylinder pressure and pollutants over 2L diesel engine tests
Jaine, Thierry. "Simulation zérodimensionnelle de la combustion dans un moteur Diesel à injection directe". Orléans, 2004. http://www.theses.fr/2004ORLE2017.
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