Dissertations / Theses on the topic 'Mesures avion'
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Gerthoffert, Jonathan. "Prévision des performances de freinage des avions sur les pistes contaminées à partir des mesures de frottement." Thesis, Ecole centrale de Nantes, 2017. http://www.theses.fr/2017ECDN0018.
Aircraft braking performances depends strongly on runway surface conditions. Water on runway can severely degrade these performances. Airport operators have to inform aircraft crews about runway surface conditions to allow pilots performing landing distance calculations. Friction measuring devices are a widely used tool to characterize runway surface conditions. However, friction results are highly scale-dependent (in terms of mass, speed, tire dimension and pressure…), which are significantly different between ground friction device and aircraft. Ground friction measurements are therefore not representative of aircraft braking performances. The methodology developed in this thesis consists in the construction of a transfer function between the friction measuring device and the aircraft from a modeling of force within the tire/runway contact area. A physical model, the so-called Brush model, has been adapted to wet and flooded runways. A specific model has been developed to describe water effect ontire/runway contact area and force distribution within this contact area. The applicability of this model to a ground friction measuring device and one aircraft has been experimentally validated. Finally, the complete methodology has been validated using experimental data from the Joint Winter Runway Friction Measurement Program (JWRFMP) and data obtained in this thesis
Brocchi, Vanessa. "Caractérisation de sources de pollution troposphérique en régions méditerranéenne et ouest-africaine par mesures in situ en avion et modélisation." Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2021/document.
The study of tropospheric pollution includes the study of trace gases coming from various anthropogenicsources that can impact scales ranging from local to global. To characterise this pollution, it is necessary tobe able to measure with precision pollutant concentrations. Within the frame of European projects, threeairborne campaigns in the Mediterranean Basin, in West Africa and in Malaysia were conducted to measuredifferent types of pollutants thanks to, among others, an infrared laser spectrometer, SPIRIT, able to rapidlymeasure on-line small variations in NO2 and CO. The data sets of these trace gases (and others) have beencombined with a Lagrangian model of particle dispersion, FLEXPART, to fingerprint different sources of localand regional air pollution. Thus, this thesis presents the measurements and the modelling work undertakenin order to define the sources of pollution of each region. It has been shown that the Mediterranean Basinwas impacted, in the mid to upper troposphere during summer, by biomass burning emissions coming fromSiberia and the Northern American continent. West African and Malaysian regions are also impacted bybiomass burning emissions transported from central Africa in the first case, and from local fires in thesecond. In addition, those regions are influenced by emissions coming from oil exploitation and maritimetraffic. FLEXPART was used in order to identify the origin of the pollution peaks measured during thecampaigns. It has been shown that atmospheric conditions, which define the injection height of the oilplatform plume, and also the emission flux are key parameters in the characterisation of the measurementsby the model
Krysztofiak, Gisèle. "Transport et chimie d'espèces soufrées et bromées dans la haute troposphère et basse stratosphère diagnostiqués par des mesures sous ballon et en avion et par modélisation." Phd thesis, Université d'Orléans, 2013. http://tel.archives-ouvertes.fr/tel-01004398.
Jaffeux, Louis. "Automatic Classification Tool for Optical Array Probes to Understand Ice Cloud Mechanisms." Electronic Thesis or Diss., Université Clermont Auvergne (2021-...), 2023. http://www.theses.fr/2023UCFA0155.
The objective of the thesis is to identify the ice growth processes occurring in clouds by using morphological data provided by the shapes of the ice particles and crystals. To accomplish this task, classification tools were developed during this thesis using innovative machine learning on 2D images from two fast imaging probes routinely mounted onboard research aircraft: the 2DS and PIP probes. This set of tools, namely convolutional neural networks (CNN) developed for both imaging probes, was evaluated and used to analyze data gathered during the ICE GENESIS Swiss Jura campaign. First, ice particle morphological and microphysical properties were extracted from the whole data. Then, the extraction of cloud properties allowed to study microphysical processes and cloud structures. Other measurements made onboard the ATR-42 during the campaign were used, notably reflectivity and MDV from the vertically pointing w-band radar RASTA, total water content from the CVI-Snow, supercooled droplets observations from the CDP-2, and humidity measurements from the WVSS-2 hygrometer. The potential of the classification tools was thereby explored, and significant contributions were achieved within the ICE GENESIS project. Microphysical interpretation of morphological data was proposed for a significant part of the ICE GENESIS data set. In addition, a conceptual scheme was developed combining the knowledge from the literature, new intuitions, and the theory of dissipative structures in order to study consumption of water vapor and precipitation formation in deep stratiform ice clouds using quantitative morphological information. This framework was mainly developed with the overall goal, to extract information from observed in situ observations, beyond a state of the art extraction of microphysical properties (crystal number and mass size distributions, without morphological distinction). The realism of the framework was confronted to an exceptional case study from the ICE GENESIS campaign, observed on the 30th of January 2021
Paris, Jean-Daniel. "Transport des polluants et variabilité atmosphérique du CO2 en Sibérie : Apport des mesures in situ aéroportées." Phd thesis, Université de Versailles-Saint Quentin en Yvelines, 2008. http://tel.archives-ouvertes.fr/tel-00358602.
Kubica, François. "Conception de lois de commande pour un avion souple." Toulouse, ENSAE, 1995. http://www.theses.fr/1995ESAE0017.
Chusseau, Maylis. "Contribution à la réduction du bruit d'hélice sur avion monomoteur à pistons." Toulouse 3, 1995. http://www.theses.fr/1995TOU30018.
Hemadou-Artigues, Claude. "Calcul des charges en vol dues aux perturbations atmosphériques par la méthode Statistical Discrete Gust." Toulouse, INSA, 1992. http://www.theses.fr/1992ISAT0021.
Bartoux, Benoît. "Assemblage par la mesure et assemblage simultané à N éléments." Amiens, 2009. http://www.theses.fr/2009AMIE0114.
This thesis is concerned with the industrial problem of the measuring assembly process, and more precisely with the simultaneous assembly of N elements. The production in aeronautics deserves a great quality for processes. Hence we need a continuous improvement both for measuring tools (laser trackers for instance), either for algorithms devoted to proceed to the measures. The usual softwares do not take into account the whole panel of tolerances. The drawbacks are a loss of quality which is not suitable for the quality for the quality of the new planes. Our algorithm allows us to take into account these constraints. To begin with, we describe the framework to model the industrial problem. In the second part, we introduce the algorithms developed during this thesis. Eventually we detail these methods on “toy cases” suggested by the quality service of AIRBUS Méaulte and we will apply them on a real case: the assembly problem of the section 12 of the A380
Doué, Nicolas. "Modélisation de l'évaporation de gouttes multi-composants." Toulouse, ENSAE, 2005. http://www.theses.fr/2005ESAE0018.
Cremezi, Cora. "Etude de la propagation du son dans l'atmosphère : application au bruit des avions en phase d'approche et de decollage." Le Mans, 2000. http://cyberdoc.univ-lemans.fr/theses/2000/2000LEMA1003.pdf.
This work deals with outdoor sound propagation in case of a high source, and particularly with aircraft take off and landing. In case of a receiver near the ground, since the sound angle incidence on the ground is small, high source sound propagation is quite well like the ground source case. Some elements of meteorology and theoretical and experimental results on main phenomena are mentioned, as the basis of our study. An overview of principle outdoor sound propagation models shows the advantages of parabolic equation methods, and particularly, the GF-PE one. Its numerical development is explained, and comparisons of simulations with benchmarks give encouraging results. These simulations allow to give a more adapted modelisation of phenomena like refraction. The GF-PE method is then introduced in a simple modelisation of the source movement, and an experimentation alIows to validate the complete model. Then, it alIows to show and quantify the sound level dispersion at ground, according to meteorological conditions
Méheut, Michaël Merlen Alain. "Évaluation des composantes phénoménologiques de la traînée d'un avion à partir de résultats expérimentaux." Villeneuve d'Ascq : Université des sciences et technologies de Lille, 2007. https://iris.univ-lille1.fr/dspace/handle/1908/1017.
N° d'ordre (Lille 1) : 3945. Titre provenant de la page de titre du document numérisé. Bibliogr. p. 255-258. Liste des publications et rapports.
Pétolas, Marie-Christophe. "Rôle du retour d'expérience dans le développement des compétences et de la sécurité en environnement dynamique : le cas des tâches et de l'activité des Personnels Navigants Commerciaux (PNC)." Paris 8, 2005. http://www.theses.fr/2005PA082607.
Méheut, Michaël. "Évaluation des composantes phénoménologiques de la traînée d'un avion à partir de résultats expérimentaux." Lille 1, 2006. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2006/50376-2006-Meheut.pdf.
Rondeau, Jean-François. "Méthode de calcul du bruit des avions dans les logements." Le Mans, 2002. http://cyberdoc.univ-lemans.fr/theses/2002/2002LEMA1013.pdf.
Delhay, Jérôme. "Développement d'un dispositif d'analyse quantittative de particules de suie par incandescence induite par laser (LII) : application à la mesure d'émissions polluantes des turbines aéronautiques." Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-83.pdf.
Constans, Florian. "Méthodologie de conception d'un système d'assistance au pilotage, application à l'aéronautique civile : sécurisation des phases d'approche et d'atterrissage." Toulouse, ISAE, 2007. http://www.theses.fr/2007ESAE0015.
Ajrouche, Hussein. "Mesures optiques d'imbrûlés - applications aux émissions des moteurs Diesel et des réacteurs." Rouen, 1995. http://www.theses.fr/1995ROUES021.
Presteau, Xuan. "Modélisation microphysique tridimentionnelle des dépôts de givre : application au givre en queue de homard sur des cylindres en flèche." Clermont-Ferrand 2, 2009. http://www.theses.fr/2009CLF22003.
Roques, Sandrine. "Étude d'un moyen aéroporté de mesure granulométrique de gouttelettes d'eau applicable à l'évaluation des conditions de givrage des avions." Toulouse, ENSAE, 2000. http://www.theses.fr/2000ESAE0006.
Quesne, Muriel. "Nouvelles procédures de gestion du trafic aérien en Europe : Influence sur la consommation de carburant et la production d'émissions." Université Louis Pasteur (Strasbourg) (1971-2008), 2004. http://www.theses.fr/2004STR13020.
Jacquet, Bernard. "Contribution à l'étude expérimentale et à la modélisation du bruit produit par l'impact d'un jet supersonique sur un obstacle." Compiègne, 1994. http://www.theses.fr/1994COMPD700.
At lift-off of Ariane launchers, the supersonic jets of the propulsion system impinge on the ground. The aim of this present study was to characterize and to modelize the noise generated by this impingement. The primary interest was to obtain a better understanding of the physical phenomena involved in the sound generation. Thus, most of the attention has been focused on the sound radiated by a supersonic hot jet impinging on a large rigid flat board. Only limited studies related to broadband noise of supersonic jet impingement have been reported. Therefore extensive acoustical experiments were carried out in order to offer support to a modelization. Acoustic field analysis and source localization lead to the following conclusions. When the board is located close to the nozzle exit, the acoustic generation is dominated by the radial wall jet. Ln the other cases, the free jet upstream of the board is the dominant source. The introduction of the board in the jet does not modify the acoustic power radiated and its spectral distribution. This characteristic of supersonic jet impingement noise allows us to assume that the instability waves in the flow still remain the dominant phenomenon in the noise generation. Flow instability calculations have been done and they confirm that, when the board is close to the nozzle exit, most of the noise is generated by the Mach wave radiation associated with the large scale turbulence convected in the wall jet. A semi-empirical model of the sound radiated by supersonic jet impingement was developed. The results confirm the conclusions of the experimental and flow stability studies. Some experiments will be carried out to extend these conclusions to higher supersonic Mach number jet
Lacroix, Cyril. "Caractérisation géométrique des assemblages flexibles par la mesure." Thesis, Cachan, Ecole normale supérieure, 2015. http://www.theses.fr/2015DENS0031/document.
The emergence of composite materials in aeronautics leads to lighter structures. However, these new materials induce new constraints to the assembly process. The adaptation is not yet complete. Indeed many operations are necessary to respect the new requirements, but are considered as non-productive. In the context of the European project LOCOMACHS, an assembly simulation tool is developed to limit the use of these operations. This thesis relates to the validation, from the measure, of the models used for flexible assembly simulation. A method to evaluate the geometry of a flexible component is implemented. The method compensates, by simulation, the effects of the environment on the component during its measurement. A sensitivity analysis of the method against changes in various measurement parameters and simulation parameters is performed in order to define a framework for implementation. Parameters of the model used to perform the compensation by simulation are not representative of the actual behavior. A modal analysis of deviations to a chosen reference geometry contributes to the adjustment of these parameters. This reference geometry is obtained by a reversal method applied in a flexible context to cancel some of the effects of the environment on the measured geometry of the component. The gap between the assembled components is the geometric key characteristic in an assembly of aeronautical composite structure. The assembly simulation, from measuring data of flexible components, enables to evaluate the gap between the components prior to assembly. Gap measurement methods in an assembly of flexible components are proposed, and they have been experimentally performed. The comparison of measured and simulated gaps highlights the performance of the simulation tool, and the difficulties in modeling actual measurement environment and actual assembly environment
Toussaint, Geneviève. "Modélisation du confinement des débris des pales d'un moteur d'avion dans un caisson hybride métal-composite." Master's thesis, Université Laval, 2007. http://hdl.handle.net/20.500.11794/19372.
Louf, Valentin. "Étude de l’eau atmosphérique par instrumentation micro-onde active et passive." Electronic Thesis or Diss., Lille 1, 2014. http://www.theses.fr/2014LIL10205.
The detection of dangerous convective precipitating system is crucial for the civil aviation safety. In this work, we develop applications for the aviation safety by using active (radar) and passive (radiometer) microwave instrumentation in order to detect precipitating systems, notably hail area. We also develop applications for the meteorology, i.e. a climatology of water vapor and the anomalous propagation of the microwave signal that is inducted by water vapor.In the first part, we study the best configuration for civil aviation airborne radars for the observation of precipitating systems, notably the frequency and the beamwidth. We have applied the constrain on the radar antenna of civil aviation that its size and its weight. Then we study the results of the dual-wavelength technic for the detection of hailstorm. This part aims to improve the quality of the observations made by civil aviation airborne radars. In the second part, we study the climatology of the water vapor diurnal cycle, and its seasonnal variations, in West Africa. Water vapor is one of the most important atmospheric gases (greenhouse effect, radiation, hydrological cycle, etc.), it is thus necessary to know in details the water vapor distribution in the troposphere. Based on this water vapor study, we then analyse the impact of the water vapor on the air refractivity and the propagation of microwaves. A climatology of anomalous propagation has been built for the instrumentation that uses microwaves
Nefissi, Naoufel. "Modélisation et mesure des efforts axiaux le long d'une fixations montées avec interférence. Application aux structures aéronautiques." Thesis, Toulouse, INSA, 2012. http://www.theses.fr/2012ISAT0042/document.
Assemblies based on interference fit fastener and preload are widely used in the fieldof aircraft construction, especially on structures heavily loaded and subjected to fatigue stresses.The performances of these assemblies are sensitive to many parameters related to the geometry and to the constitutive materials. To improve the quality of these assemblies and achieve the assembled parts. This simple model produces results very similar to those obtained with thereference model. A dedicated numerical model, based on axisymmetric finite elements and developed using Matlab code, is also proposed. It is able to evaluate the influence of parameter variations along the interface between the parts while considering the side effects. An experimental study based on an assembly instrumented with Fiber Bragg Gratings is presented.The correlations between the experimental results and those from the models are very satisfactory lifetime gains expected, it is important to use, from the early design phase, fast and reliable models in order to evaluate the influence of input parameters on the most significant efforts that take place around the fastener. In a preliminary phase, the work focuses on clearly identifyingthe mechanical phenomena characterizing the behavior of the mechanical connections understudy, using a very detailed finite element reference model of the assembly process. An analytical approach is then developed. It leads to a first level model for estimating loads and stresses in the assembled parts. This simple model produces results very similar to those obtained with the reference model. A dedicated numerical model, based on axisymmetric finite elements and developed using Matlab code, is also proposed. It is able to evaluate the influence of parameter variations along the interface between the parts while considering the side effects. An experimental study based on an assembly instrumented with Fiber Bragg Gratings is presented.The correlations between the experimental results and those from the models are very satisfactory
Jacob, Christelle. "Management de l'incertitude pour les systèmes booléens complexes - Application à la maintenance préventive des avions." Thesis, Toulouse, ISAE, 2014. http://www.theses.fr/2014ESAE0010/document.
Standard approaches to reliability analysis relies on a probabilistic analysis of critical events based on fault tree representations. However in practice, and especially for preventive maintenance tasks, the probabilities ruling the occurrence of these events are seldom precisely known. The aim of this thesis is to study the impact of epistemic uncertainty on probabilities of elementary events such as failures over the probability of some higher level critical event. The fundamental problem addressed by the thesis is thus to compute the probability interval for a Boolean proposition representing a failure condition, given the probability intervals of atomic propositions. When the stochastic independence is assumed, we face a problem of interval analysis, which is NP-hard in general. We have provided an original algorithm that computes the output probability interval exactly, taking into account the monotonicity of the obtained function in terms of some variables so as to reduce the uncertainty. We have also considered the evolution of the probability interval with time, assuming parameters of the reliability function to be imprecisely known. Besides, taking advantage of the fact that a probability interval on a binary space can be modelled by a belief function, we have solved the same problem with a different assumption, namely information source independence. While the problem of computing the belief and plausibility of a Boolean proposition are even harder to compute, we have shown that in practical situations such as usual fault-trees, the additivity condition of probability theory is still valid, which simplifies this calculation. A prototype has been developed to compute the probability interval for a complex Boolean proposition
Primus, Julien. "Détermination de l'impédance acoustique de matériaux absorbants en écoulement par méthode inverse et mesure LDV." Thesis, Toulouse, INSA, 2012. http://www.theses.fr/2012ISAT0026/document.
While aircraft noise constraints become increasingly stringent, efficient duct treatment of turbofan engines requires an accurate knowledge of liner impedance with grazing flow at high acoustic levels. This thesis aims at developing an impedance eduction method in the presence of grazing flow. The inverse process is based on acoustic velocity fields acquired by Laser Doppler Velocimetry (LDV) above the liner. The liner acoustic impedance is obtained by minimization of the distance between the measured acoustic velocity field and the simulated one. Computations rely on the resolution of the 2D linearized Euler equations in the harmonic domain, spatially discretized by a discontinuous Galerkin scheme. The gradient of the objective function is achieved by the resolution, at each iteration on the liner impedance, of the direct and adjoint equations. The solver is first validated on academic test cases, then on experimental results of acoustic pressure measurements at the rigid wall opposite the liner. Secondly the method is applied to acoustic velocity measurements obtained by LDV above the liner without flow, in the ONERA B2A test bench. The last step consists in taking into account the effects of a sheared grazing flow. The impedances educed from LDV measurements in the presence of flow namely allowed to gain insight into the absorption phenomena occuring in the B2A test bench
Copin, Etienne. "Fonctionnalisation de barrières thermiques aéronautiques YSZ issues de la voie sol-gel : mesure de température et diagnostic de l'endommagement par fluorescence." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2015. http://www.theses.fr/2015EMAC0011/document.
The aim of this work is to develop and study yttria stabilised zirconia (ZrO2 + 9.8at% Y2O3, YSZ) based thermal barrier coating (TBC) « sensor » systems deposited by a dip coating sol-gel process, and dedicated to temperature measurement and to the monitoring of damaging occuring within the thickness of the coatings, using fluorescence thermometry methods. These methods are based on the monitoring of the fluorescence properties of photoluminescent activators from the trivalent lanthanide ions group (Ln3+), such as samarium Sm3+, europium Eu3+, dysprosium Dy3+, erbium Er3+ and thulium Tm3+. These activators are directly incorporated into the zirconia YSZ host matrix lattice, which is semi-transparent at their emission wavelengths mainly falling in the visible range. An experimental set up was especially developped for the application of these methods. The characterisation of the different YSZ:Ln3+ powders synthesized by a sol-gel process allowed to optimise the compositions, and thus maximize the fluorescence signal intensity while avoidind any alteration of the zirconia crystal structure required from for a TBC material. The sol-gel dip coating process allowed to deposit functionalised multilayer TBC prototypes integrating up to three fluorescent layers with distinct emission wavelengths distributed throughout the thickness. Such coating architectures allow, with the fluorescence thermometry methods identified, to optically probe the coating across the whole thickness for future applications aiming to determine the thermal gradient in TBCs. Functionalised TBCs containing pre-calibrated delamination defects at the metal/ceramic interface were also used to compare the interest of the reflectance enhanced fluorescence method and an IR thermography method for early monitoring of TBC spallation. At last, the potential offered by YSZ:Ln3+ powders as thermal history sensors alternative to temperature sensitive paints was also investigated
Roux, Élodie. "Pour une approche analytique de la dynamique du vol." Toulouse, ENSAE, 2005. http://www.theses.fr/2005ESAE0019.
Di, Cioccio Alexandre. "Articuler sécurité et performance : les décisions d'arbitrage dans le risque en aéronautique." Thesis, Paris, CNAM, 2012. http://www.theses.fr/2012CNAM0784/document.
This research is in the field of reliability of complex socio-technical systems and aims to develop a new approach to allow trade-offs between performance and safety: engineering resilience. The ability of systems to cope with disturbances ultimately depends on the operators of these systems. They must make trade-offs between criteria that may conflict: immediate economic criteria (i.e. to ensure business performance), safety criteria (i.e. give up to meet the immediate production objective). The thesis focuses on the activity of an airline’s operators, in charge of assistance via telephone for aircrew who report a technical complaint. It can be treated immediately; is it benign, or conversely should it lead to the cancellation of the flight?The thesis assumes that in an ultra-safe and ultra rule-based system, conflicts between safety and performance occur when the "rule-based safety" conflicts with "adaptative safety". To defend this thesis, three empirical studies have been implemented. Thus, several methods were used in combination: observation and activity analysis, simulation of activities, questionnaires and auto-confrontation.The results obtained allowed at first to objectify the trade-offs between performance and safety, then in a second instance to identify the criteria governing such trade-offs and explain the processes that underlie them.These results permit, on one hand, to propose acceptable solutions such as the feedback by comparing the practices and assimilate the “adaptative safety” as a subset of “rule-based safety”, and on the other hand to overcome our negative view of violations by treating them as a form of operators’ intelligence in action
Badufle, Cécile. "Définition conceptuelle d'avions : vers une optimisation multiobjet, robuste et incertaine." Toulouse 3, 2007. http://www.theses.fr/2007TOU30294.
Aircraft sizing studies consist in determining the main characteristics of an aircraft starting from a set of requirements. These studies can be summarized as global constrained optimisation problems with typically one thousand parameters and almost as many constraints. The constraints express physical feasibility and the requirements to be satisfied, and the objectives are market driven performances of the aircraft. Moreover, aircraft sizing is typically a multicriteria optimisation problem because of some competing objectives. The aim of this thesis is to introduce new mathematical methods that can be useful in a future project sizing tool to treat the aircraft configuration optimisation problem. We contributed in improving the optimisation methods that are currently used in the Airbus Future Project Office. By using genetic algorithms, we made the mono-criterion optimisation process more robust. Then, we introduced multicriteria optimisation methods because we had several conflicting criteria to consider. As the calculation times became important, we decided to substitute the aircraft model by a surrogate model. We implemented radial basis functions to approximate the constraint and the objective functions. Finally, we propagated the model uncertainty to assess the robustness of the optimisation results and we proposed a possible outcome of the integration of these different techniques in order to yield the engineers a global and operational perception of the design space
Presteau, Xuan. "Modélisation microphysique tridimentionnelle des dépôts de givre." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2009. http://tel.archives-ouvertes.fr/tel-00724453.
Louf, Valentin. "Étude de l’eau atmosphérique par instrumentation micro-onde active et passive." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10205/document.
The detection of dangerous convective precipitating system is crucial for the civil aviation safety. In this work, we develop applications for the aviation safety by using active (radar) and passive (radiometer) microwave instrumentation in order to detect precipitating systems, notably hail area. We also develop applications for the meteorology, i.e. a climatology of water vapor and the anomalous propagation of the microwave signal that is inducted by water vapor.In the first part, we study the best configuration for civil aviation airborne radars for the observation of precipitating systems, notably the frequency and the beamwidth. We have applied the constrain on the radar antenna of civil aviation that its size and its weight. Then we study the results of the dual-wavelength technic for the detection of hailstorm. This part aims to improve the quality of the observations made by civil aviation airborne radars. In the second part, we study the climatology of the water vapor diurnal cycle, and its seasonnal variations, in West Africa. Water vapor is one of the most important atmospheric gases (greenhouse effect, radiation, hydrological cycle, etc.), it is thus necessary to know in details the water vapor distribution in the troposphere. Based on this water vapor study, we then analyse the impact of the water vapor on the air refractivity and the propagation of microwaves. A climatology of anomalous propagation has been built for the instrumentation that uses microwaves
Lallement, Julien. "Modélisation et simulation numérique d’écoulements de films minces avec effet de mouillage partiel." Thesis, Toulouse, ISAE, 2019. http://www.theses.fr/2019ESAE0005/document.
The ice accretion on surfaces encountered in aeronautics (wings, nacelle lips, sensors)is considered as a major risk for aviation safety. The consequences observed are the degradationof the aerodynamic performances that can lead to the aircraft stall, disturbancesin the engines that can lead to flame out or clogging of the sensors. That is why aircraftmanufacturers are developing thermal protection systems against icing. The wateraccumulated on the surfaces thus remains in the liquid state and forms a thin film. Thedynamic properties (thickness, velocity and spreading) and thermal properties (temperature,evaporation rate) of the film in the presence of a sheared air flow make it possible apotential refreezing of the water film on unprotected surfaces (”runback ice” phenomena).Since flight or wind tunnel tests are generally expensive and difficult to set up, numericalsimulation has become an effective and complementary tool to design these systems. Themain purpose of this thesis is to develop a model integrated in a numerical tool to predictthe transport of liquid water on a surface which might take the form of a film, a rivulet ora droplet. An integral approach based on a shallow water type model is adopted. It makesit possible to describe the macroscopic dynamics of a three-dimensional liquid film onrealistic configurations and within reasonable computing times compared to a full Navier-Stokes computation. An extended formulation is proposed, it corresponds to a second orderdifferential system and thus allows to use arbitrary surface meshes. Contrary to modelsavailable in the literature, the one proposed in this manuscript has the advantage of takinginto account capillary and wetting phenomena without validity limit in term of staticcontact angle. An energy conservation equation ensuring the thermodynamic consistencyof the calculated solutions is derived from the extended model governing fluid dynamics.A Finite Volume discretization of the system is proposed. Numerical simulations validatethe model for both static and dynamic academical wetting configurations. The transitionof a continuous film into rivulets is also simulated
Djiknavorian, Pascal. "Étude des algorithmes d'approximation de fonctions de croyance généralisées." Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30400/30400.pdf.
This research is about the solving of the computational difficulty of data fusion in the evidence theory of Dempster-Shafer theory and Dezert-Smarandache theory. We study the use of a variety of known approximation algorithms as well as a new approximation algorithm that we propose. We also study known metrics between bodies of evidence as well as two new metrics that we develop. Finally, we study the possibility of using an optimization method to automatically select the parameters of approximation with performance criteria. Keywords: Dezert, Smarandache, Dempster, Shafer, Fusion, Belief functions.
Boubaker, Nadhem. "Étude des pertes atypiques dans les machines synchrones à aimants à hautes performances pour applications aéronautiques." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT284.
The main aim of this thesis was to study and experimentally assess the additional iron losses in the stator (electrical lamination steel) of high performance permanent magnet synchronous machines (PMSM) designed for aircraft applications, in relation with the “more-electric-aircraft” project. This international program consists of gradually introducing electrical systems to replace onboard hydraulic and pneumatic systems, for example to power the landing gear wheels (Electric Green Taxiing System)…The extra iron losses are caused by manufacturing processes (cutting, sticking, insulation, stacking, pressing, shrink-fitting, thermal treatment …) and the real conditions of use of electrical motor (namely: rotational flux, saturation, high frequency…). Indeed, the mechanical and thermal stresses during the manufacturing steps can deteriorate the magnetic properties of the material and significantly increase the iron losses. These aspects are difficult to accurately evaluate by analytical models or standard measurements (Epstein frame…) and require experimental assessment to precisely calculate the motor efficiency.First of all, we started by developing a test bench equipped with drive motor: PMSM 8000 RPM ; 42 kW. For accurate assessment, the losses in this machine are separated on the test bench, for example, the mechanical losses (bearings loss & windage loss) have been measured at different speed with a non-magnetic rotor. Rotor magnets eddy-current losses cannot be isolated from iron losses, for this reason they have been calculated using a 3D finite element model. To limit rotor loss we then used a non-conductive retaining sleeve (heat shrink sleeve). In the winding, we used bar-wound conductors, which is an original winding technology developed in our laboratory, and whose advantage among others is the unusual copper fill factor that reaches almost 90%.Subsequently, we explored the high frequency machines (>1 kHz) in order to increase the power-to-weight ratio (cross the threshold of 2.5 kW/kg). We proposed, the following to the analytical and finite element study, a first conventional prototype with a power-to-weight ratio equal to 4.5 kW/kg with: FeCo stator (Vacodur49 0.2 mm), FeSi rotor and NdFeB magnets (N35EH), operated at 1666 Hz, 5000 RPM and 94% efficiency at full load. A second motor had been also proposed with both rotor and winding in aluminum, in this case the power-to-weight ratio reaches around 6 kW with, however, less efficiency (93%).Finally, this HF motor was tested, at no load, on the aforementioned test bench. The experiments were carried out on a multitude of FeCo and FeSi stator core samples coming from different manufacturing processes (insulation: bonding varnish and C-5 varnish; cutting: laser and EDM “Electrical Discharge Machining”; thermal treatment) in real operating conditions of a high frequency PM machine in order to experimentally obtain the famous “additional coefficient” of iron losses (Kadd)
Thabet, Rihab El Houda. "Détection de défauts des systèmes non linéaires à incertitudes bornées continus." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0283/document.
The monitoring of industrial and/or embedded systems is a major concern accordingto their increasing complexity and requirements to respect the mission profiles. Detection of anomaliesplays a key role in this context. Fundamentally, model-based detection procedures consist incomparing the true operation of the system with a reference established using a fault-free model.However, the monitored systems often feature nonlinear dynamics which are difficult to be exactlycharacterized. The approach considered in this thesis is to enclose their influence through boundeduncertainties. The propagation of these uncertainties allows the evaluation of thresholds aimingat ensuring a good trade-off between sensitivity to faults and robustness with respect to disturbanceswhile maintaining a reasonable computational complexity. To that purpose, an importantpart of the work adresses the extension of classes of dynamic models with bounded uncertaintiesso that interval observers can be obtained with the related inclusion and stability proofs. Based ona time-varying change of coordinates, LTI, LPV and LTV dynamics are gradually considered tofinally deal with some classes classes of nonlinear continuous dynamics with bounded uncertainties.A transformation of such nonlinear models into LPV models with bounded uncertainties has beenused. A first study on nonlinearities involved in longitudinal flight dynamics is presented. A complementarywork deals with an explicit characterization of measurement noise variability (randombehavior of noise within measurement) in a bounded error context. Combining this data-drivenapproach with a model-driven one using an interval predictor, a promising method for the detectionof faults related to the position of aircraft control surfaces is proposed. In this context, specialattention has been paid to the detection of runaway and jamming of an elevator
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)
Brandelero, Julio Cezar. "Conception et réalisation d'un convertisseur multicellulaire DC/DC isolé pour application aéronautique." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14246/1/Brandelero.pdf.
Papaïx, Benoît. "Outiller la conception centrée utilisateur en milieu industriel complexe : des techniques de traitement automatique de textes pour la conception des cockpits." Thesis, Bordeaux 2, 2011. http://www.theses.fr/2011BOR21899/document.
In the professional aeronautical field (one of the safest in the world), human error management must be improved to reach a better safety level. To do this, a user centred design process has to be implemented. However, due to the complexity of socio technical systems, the implementation of an efficient user centred design process could be challenging. To ease this process, our study aims to develop and validate specific tools, particularly for processing large amounts of textual data. In our study, we will firstly undertake an extraction of scenarios that can contain human errors in a specific database. This extraction will be based on expert judgment (control condition). Secondly, we will confront the control condition with results obtained automatically. The results of this comparison allow:1/ The identification of relevant algorithms for automatic information extraction within large textual databases (Nearest Neighbour, Bayesian filtering);2/ The identification of a methodology to extract risk situations that could be included in specific studies. This step is very important for the user centred design process.Links that we have established between our results and incident/accident studies allow us to consider positive impacts on aviation safety
Mawhin, Barbara. "Stratégies de protection de la performance pour la conception de cockpits résilients : le cas de la fatigue en situation inattendue de résolution de problème." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05H122.
Escouflaire, Marie. "Theoretical and Numerical Investigation of Time-Domain Impedance Models for Computational AeroAcoustics." Thesis, Le Mans, 2014. http://www.theses.fr/2014LEMA1003.
The reduction of acoustic emission induced by civil aircraft around major airports has become an important societal issue. To reduce the fan noise, induced by the engines, which has become preponderant over the past years with the advent of turbofan engines, manufacturers are led to generalize the employment of acoustic absorbing materials (or acoustic “liners”). The present thesis is related to the numerical prediction of such absorbing materials, in the context of time-domain CAA (Computational AeroAcoustics) methods. Such modeling raises several key questions, which are related to various aspects such as the type of flow involved (boundary layers effects, etc.), the sound levels considered (non-linear phenomena), the diffraction effects induced by ruptures of impedance, etc. The present study then consists in validating and improving the time-domain impedance boundary condition implemented in Onera’s structured CAA solver (named sAbrinA.v0). Theoretical developments are first devoted to the modeling of impedance in the time-domain, and lead to a discussion on the generalization of this modeling. The work then consists in CAA-simulating several canonical tests of noise absorption by acoustic liners. Outputs are compared against experimental and/or analytical results, delivering new insight in the way noise absorption materials can be accurately modeled and simulated using time-domain CAA-approaches
Simon, Coraline. "Méthodologie pour le durcissement et l’accélération d’essais sur composites à matrice céramique aéronautiques." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0681/document.
With the aim of an introduction in civil aeronautics, the certification of Ceramic Matrix Composites (CMC)requires to demonstrate the correct behavior of the material during the whole lifetime of the aircraft (about50000h), in high-temperature oxidizing environments and under the stress levels required by the applications.The goal of this thesis is to identify a methodology to accelerate ageing tests in order to get, in shorterdurations, results that are representative of the behavior of the material in standard conditions. The studiedcomposite includes a self-healing matrix which efficiency is linked in a complex way to temperature andhumidity. A thorough understanding of degradation mechanisms is therefore required in order to identifyrelevant accelerating levers. The influence of the selected test parameters (water partial pressure, type ofmechanical loading, frequency of cyclic loading, temperature) on the damage kinetics has been analyzed, whilechecking that the damage mechanisms were not modified. Non destructive monitoring techniques are essentialto quantify in real time the damage level of materials under different test conditions: acoustic emissionmonitoring has been used, and an original method of damage monitoring using electrical resistivity has beendeveloped. Two electromechanical models were proposed, describing the evolution of electrical resistance atroom temperature and under oxidizing conditions. Lifetime estimations based on these techniques led topropose a methodology towards accelerated testing on CMCs
Berrebi, Johanna. "Contribution à l'intégration d'une liaison avionique sans fil. L'ingénierie système appliquée à une problématique industrielle." Phd thesis, Ecole Polytechnique X, 2013. http://pastel.archives-ouvertes.fr/pastel-00800141.
Doucet, Annie. "Étude cas-témoins de l'épisode d'influenza aviaire hautement pathogène (H7N3) en Colombie-Britannique en 2004 utilisant des scores de biosécurité comme mesure de risque." Thèse, 2008. http://hdl.handle.net/1866/7192.