Дисертації з теми "Pales de rotor"
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Duran-Venegas, Eduardo. "Modélisation et optimisation d'un rotor à pales flexibles." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0195.
Rotors have been historically developed for harvesting and propulsion. For wind turbines and helicopters, decades of research have been done to optimize their design. For recent applications, such as drones, no such a research effort has been made. The high flexibility of the rotor and the different operational conditions still constitute challenging issues for their design. In this work, a coupled fluid-structure model is proposed, taking into account the flexibility of the blades in non-conventional operational conditions.The model is sufficiently simple and robust to permit extensive parameter studies. It includes a model for the wake, a model for the flexible rotor structure and the coupling. Two different wake models are considered: a classical Joukowski model, where two vortices are emitted per blade, one at the tip and one at the axis, and a generalized Joukowski model where the axial vortex is replaced by a hub vortex emitted away from the center. A stability analysis of the solutions derived with the classical Joukowski model is performed. The convective/absolute nature of the instability is analysed for various operational conditions.Stationary wake solutions are used to calculate the flow in the rotor plane. Kutta-Joukowski law and Blade Element Theory are applied to obtain the aerodynamic loads exerted on the blades. The full coupling of the rotor with its wake is first implemented for a rigid configuration. Coupled solutions are obtained for different rotors and compared to experimental and numerical data published in the literature. Finally, blade flexibility is considered using a rod model for the blade
Lebel, Guilhem. "Prévision des charges aéromécaniques des rotors d'hélicoptère : Application aux pales à double flèche." Thesis, Lyon, INSA, 2012. http://www.theses.fr/2012ISAL0025.
New generation blades have led to new load computation problems due to the evolution of the general shape, with forward and backward sweep. The BlueEdgeTM blade pattented by Eurocopter imposes to reconsider the development methodology and thus it is no longer possible to speak of straight blades and the models used for load computation have to be evaluated. The objective of this thesis is to determine what has to be modified and improved in current load computation methodology in order to reach an acceptable predictive level. This work considers both aerodynamic and dynamic models implemented in the HOST multi-body computer code. The aerodynamics models are based on the hypothesis of a two dimensional flow. The use of the CFD software \emph{elsA} is evaluated. Attention is given to rotor dynamics models that have an impact on loads, such as lead-lag damper models, blade element models and hub models. This thesis presents the different models and gives orientations relating to efficient load computation methodology. The aerodynamics models are compared to windtunnels experiments from the literature. This study leads also to perform flight tests and to investigate the dampers behavior on test benches in order to confront the computed loads to the reality of the helicopter operation. The proposed methodology is able to compute with a good accuracy rotor loads for stabilized flight cases
Roux, Louis. "Modélisation dynamique du départ d'une pale et de la tenue des pales suiveuses dans une turbomachine." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI056.
During the certification process of a turbo engine, the engine manufacturer has to demonstrate that the loss of a rotor blade does not lead to the "knocking-off" phenomenon, in other words to the cascading failure of the successive blades. Generally, this demonstration is carried out through a costly rig test driving to the partial destruction of the engine. Thanks to the improvement of computational resources, it is now possible to simulate the transient response of the structure subjected to this complex loading. The knowledge of material behavior turns out to be the essential starting point for the simulation. However, only a few studies have been published on the dynamic behavior of nickel-based single crystal superalloys at high temperature reaching 1000°C. With a view to efficiently predicting the consequences of impacts on turbine blades, experimental and numerical works have been conducted on a single crystal frequently used by Turbomeca. High-temperature dynamic compressive tests on Split Hopkinson Pressure Bars (SHPB) have enabled to estimate the material plasticity level and hardening, depending on the crystal orientation, strain rate and temperature. The parameters of a viscoplastic anisotropic law have been identified to effectively model the MC2 macroscopic behavior under highly intense and multiaxial loading. At Safran Snecma Villaroche, ballistic tests have been undertaken on both single crystal plates and blades under high temperatures. In order to consider the fragmentation of profiles in blade-off simulations, a plastic strain criterion depending on stress triaxiality has been calibrated and validated by comparison with the impacts on blades. Post-mortem digital images correlation measurements and high-speed camera recordings have confirmed these simulations. Using LS-Dyna solver, a blade-off modeling strategy has been created and applied to an actual blade-off industrial case. Finally, a rotordynamics approach has been developed and validated with the aim of separately analyzing the primary damage, caused by direct impacts on the first following blades, and the secondary damage due to the effects of unbalance on a flexible rotor
Droz, Christophe. "Guidage des ondes d'ordre élevé dans les composites : application au dégivrage en vol des pales d'hélicoptères." Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0026.
When helicopters fly through extreme conditions, ice can aggregate on their blades and seriously affect the aircraft performances. Recently, an increasing research effort was devoted to the development of affordable low power de-icing solutions. In this thesis, a wave-based approach is adopted to prevent and/or remove ice aggregates from the surfaces of helicopter rotor blades. The de-icing strategy uses specific high-order guided waves to exceed the shear adhesion strength of ice accretion profiles. Experiments are conducted in order to update the FE model of a realistic rotor blade, then a Model Order Reduction strategy is developed for the Wave Finite Element Method. It involves a projection of the state vectors on a reduced basis of propagating waves shapes, and enables broadband wave analysis in structurally advanced 1D and 2D periodic structures. Guided wave propagation is studied within a helicopter rotor blade, and wave localization and conversion effects are discussed in various 1D and 2D composite waveguides. The interactions of high-order waves with ice aggregates and other types of structural singularities are also examined by means of a Diffusion Matrix Method. Then, time-domain propagation in coupled waveguides subjected to a wave pulse is analysed through a computationally efficient wave-based formulation. Finally, a smart actuator network is designed for the generation of high-order wave pulses and validations are conducted in a composite plate and a Super Puma rotor blade using time simulation
Dubois, Patrick. "Intégration de pales en céramique dans un rotor de microturbine axiale en configuration renversée." Mémoire, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/9714.
Taufik, Atik. "Contribution au développement d'un outil de conception des poutres composites : application aux pales d'hélicoptères." Toulouse, ENSAE, 1996. http://www.theses.fr/1996ESAE0017.
VINCENTI, JEAN. "Etude de l'influence des defauts de pales sur la charge dynamique du rotor et la stabilite de l'helicoptere." Paris, ENSAM, 1995. http://www.theses.fr/1995ENAM0011.
Skladanek, Yan. "Formulation d’un élément fini de poutre pour la dynamique des pales d’hélicoptère de géométrie complexe." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0122.
Structural, shape and performances optimization in helicopter rotor leads to design composite blades initially curved and twisted. This design yields a highly coupled behavior between torsion, longitudinal and bending motions of blades. Besides, dynamic studies of blades have to be performed in the rotational frame, so that all rotatory effects could be siezed by the modeling. A highly accurate non-linear straight beam finite element is proposed to predict the static deformation under aerodynamic and centrifugal loads and achieve dynamic and stability analysis. This elastic model is to be implemented in a comprehensive rotorcraft analysis code, which means accuracy, reliability and calculation time compromise. Model validation is based on analytical, numerical and experimental investigations. The developed model reveals to be very accurate for new blade design including important twist angle and initially curved shape. It is expected to improve prediction quality for full helicopter simulation tools, undergoing strong coupling with advanced aerodynamic model
Aymard, Emmanuel. "Détermination des efforts aérodynamiques s'exerçant sur une surface portante en rotation par une méthodologie basée sur la vélocimétrie laser : application aux pales d'un rotor d'hélicoptère en vol d'avancement." Aix-Marseille 2, 1998. http://www.theses.fr/1998AIX22113.
Proulx-Cabana, Vincent. "Algorithmes non-linéaires rapides pour l’aéroélasticité d’ailes rotatives." Electronic Thesis or Diss., Toulouse, ISAE, 2024. http://www.theses.fr/2024ESAE0001.
This thesis describes the developments of rapid non-linear computational algorithms for rotary-wing aeroelasticity. The main focus of this thesis is the development of the aerodynamic method that is then coupled with a structural solver to produce aeroelastic simulations. For the aerodynamic model, a so called medium fidelity tool based on the potential methods is chosen to capture aerodynamic interactions and phenomenon neglected by the faster low fidelity methods while obtaining the results at a much reduced computational cost compared with the higher fidelity methods based on the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations. The blades structure is modeled with Euler-Bernoulli beam elements in a Finite Element Method (FEM) to obtain the aeroelastic deflections.The thesis begins with an introduction, followed by an extensive literature review comparison and a small chapter presenting the overarching methodology. Then, the main research objectives are covered in the following chapters and the thesis ends with a conclusion that summarizes the work and presents recommendations. Some optional supplementary materials can be found after the references in the appendices.The main objectives of the thesis are:- Improve the aerodynamic blade loads prediction of a medium fidelity method without increasing significantly the computational cost.- Ensure numerical stability in hover flight, with or without ground effect.- Expose the method sensitivity to its parameters.- Couple the aerodynamic method with a structural method to perform quasi-static blade aeroelasticity simulations.The first objective is obtained with the Unsteady Vortex Lattice Method (UVLM) and its modifications from the classical method to perform rotary wing simulations. The improvement of load predictions is accomplished via non-linear viscous-inviscid coupling (NL-UVLM) that is well known for fixed-wing aerodynamics, but was more rarely used for rotary-wing aerodynamics.The NL-UVLM method is stabilized in hover, especially in ground effect, with the replacement of tightly linked wake panels by free moving particles, namely the Vortex Particles Method (VPM). However, the introduction of vortex particle causes two difficulties: 1) the increase of the computational cost and 2) numerical instability. The first issue is addressed by using the Fast Multipole Method (FMM) to reduce computational complexity. The numerical instability is controlled by adding a Large Eddy Simulation (LES) viscosity. The NL-UVLM-VPM results compare well for the global coefficients, distributed loads and pressure coefficients with many higher fidelity methods and experimental results.The effects of the parameters of the model are explored since they play an important role in its robustness and accuracy. The NL-UVLM-VPM can produce stable and consistent long-time running simulations and obtain results in good agreement with 3D URANS if the parameters are carefully selected.The present work builds upon a previous project that had coupled steady VLM method to a non-linear FEM model to simulate static aeroelasticity of airplane wings. The software is improved to simulate quasi-static rotor blade aeroelasticity. The centrifugal force, necessary for accurate rotary-wing aeroelasticity, is added explicitly as an external force in the FEM. The method is verified compared to other FEM simulations from the literature and the different structural parameters are tested on a simplified single bladed rotor test case. The aeroelastic results are consistent with the expected behavior for each structural parameter. Finally, comparison with the experimental approach developed in the context of this project is presented.The method presented in this work could find applications in rotary-wing, wind turbine and propeller aerodynamic and aeroelastic design while improving the fidelity of flight simulators
Zehner, Paul. "Étude aéroacoustique de l'interaction orthogonale pale/tourbillon." Thesis, Paris, ENSAM, 2018. http://www.theses.fr/2018ENAM0005/document.
The aeronautics industry focuses on decreasing its ecological footprint and increasing airplanes efficiency. One way for this is to design more efficient motors, like CROR, for Counter Rotating Open Rotor. This engine, also called propfan, is quite close to a turbofan, but with a pair of counter rotating propellers instead of ducted fan, which increase its yield. The efficiency is about 30 % higher than a turbofan of equal power, but it generates a lot of noise.This noise has several causes, the main one at low speed (typical takeoff or landing situation), is due to the interaction between propellers. The higher contribution to this interaction is the interaction between rear blades and tip vortexes generated by front blades. The noise generation process of this interaction is complex. It has been shown in previous studies at Onera that vortex kind plays an important role on the generated noise.The goal of this thesis is to identify and classify the influent parameters of this interaction on the noise generation, especially the blade geometry and the vortex properties, and then, to find a silent configuration.To this aim, a parametric study is set up. This study is based on a numerical approach and uses the Cassiopée and Kim computational softwares, developed at Onera. Physical models uses Euler unsteady equations, in their three dimensional and compressible expression, for the CFD and Ffowcs-Williams and Hawkings equations, in their rotating solid surface expression, for the CAA. Simulations are run on high orders schemes and use the Chimera method. Analyses are based on both close field fluid dynamics and far field acoustics.With the results of this parametric study, silent and optimal blades design criteria will be find out.Then, with these criteria, it will be possible to design CROR blades which are aeroacoustically efficient as well as aerodynamically efficient. The outcomes of this thesis are not limited to CROR situation only: any configuration where a blade crosses a vortex orthogonally can benefits from this study, by instance the interaction in a helicopter between the main rotor flow and the tail rotor blades
Joulain, Antoine. "Simulation aérodynamique d'extrémités de pales de rotors sustentateurs d'hélicoptère." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4768.
Helicopter aerodynamics is strongly influenced by the vortices generated from the rotor-blade tips. The design of efficient tip shapes is a challenging task because of the complexity of the aerodynamic phenomena involved and the lack of local blade-tip flow measurements. This work provides a contribution to the design of helicopter tips in hover. An efficient, relatively simple and quick numerical method is set up to study rotating blade tips in fixed-wing configurations. The accuracy of the method is shown at each step of the construction by comprehensive comparisons with reliable experimental data from the literature. First, an efficient steady Reynolds-Averaged Navier-Stokes method is constructed using ONERA's elsA code. Comprehensive studies of convergence, grid dependence and sensitivity to the numerical method are performed in two and three dimensions. The very good agreement of the solution with measurements and the accuracy of the numerical method allow a physical analysis with unprecedented detail of the vortex generation and roll-up near square and rounded wing tips. The new methodology of framework adaptation is then presented. An uncoupled hybrid strategy is set up using AIRBUS HELICOPTERS' Comprehensive Analysis code HOST and the Computational Fluid Dynamics solver elsA. Global and local performance calculations are validated for all investigated test cases. Comparison with previously published adaptation methods indicates considerable improvement in the prediction of the blade aerodynamics
Michea, Bertrand. "Etude des sillages de rotors d'helicoptere en vol d'avancement et de leur influence sur les performances du rotor (interaction pale-tourbillon)." Paris 6, 1992. http://www.theses.fr/1992PA066255.
Bouchet, Eric. "Étude du bruit d'interaction pale-sillage d'un rotor principal d'hélicoptère." Le Havre, 2002. http://www.theses.fr/2002LEHA0011.
Understanding the mecanisms responsible for the BWI noise of helicopter main rotor which occures during perpendicular blade-vortex interaction. An extensive analysis of the blade pressure is performed to get a deeper insight of the BWI mecanism. A stability analysis of modelization of the incident flow (two rectilinear and parallel filaments) is undertaken. The numerical and theoritical results are found to be in good agreement and consistent with the proposed instability hypothesis
Richard, Hugues. "Dynamique des tourbillons d'extrémité de pale de rotor en vol d'avancement." Aix-Marseille 2, 2005. http://www.theses.fr/2005AIX22082.
Imine, Omar. "Comportement aérodynamique d'une demi-aile en paroi à Mach=0. 6 : application aux extrémités de pales d'hélicoptère." Aix-Marseille 2, 1987. http://www.theses.fr/1987AIX22113.
Tawk, Issam. "Contribution à la modélisation à l'impact de pales d'hélicoptère." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/503/.
This study is a contribution to the modelling of impact on helicopter blades. Experimental tests of impact were made with a compressed gas gun on sections of blades at different levels of energy. These tests were used to establish the damage in terms of impact velocity. Additional tests showed that the stratification and the reinforcement of the skin change the behaviour of the blade during the impact. A modelling approach is developed with the finite element code RADIOSS. It consists in controlling the degradation of the front edge that appears by a break of the resin and by the appearance of bundles of fibers. This approach is realised by modelling the resin with 3D damaged elements and the bundles of fibers by 1D elements. Delamination was modelled with a thin layer of damaged elements. To enrich the proposed modelling and to take into account all types of delamination observed experimentally, a local global approach for modelling the delamination is developed. This approach, built with the use of a specific 3D element PEC, is based on the VCCT method. It is validated through the simulation of different beam tests DCB, ELS, ENF and ADCB
NASTASI, VALERIE. "Etude numerique du tourbillon d'extremite de pale du rotor d'helicoptere en regime compressible." Paris 6, 1997. http://www.theses.fr/1997PA066481.
Dobrev, Ivan. "Modèle hybride de surface active pour l’analyse du comportement aérodynamique des rotors éoliens à pales rigides ou déformables." Paris, ENSAM, 2009. http://www.theses.fr/2009ENAM0034.
This work presents the exploration and modeling of flow past wind turbine rotor. The aim is to propose an actuator surface hybrid model to simulate rapidly the flow and also be coupled with structure solver for fluid structure interaction. Besides numerical simulation, the PIV and hot wire explorations are also carried out. These explorations of flow around the wind turbine and rotating blades airfoil have provided the data necessary to calculate 3D airfoil aerodynamic performance while in rotation. The results of these measurements are also used to validate the proposed model. The new actuator surface model is developed to model the flow around wind turbine rotor. To implement the proposed model, Navier-Stokes solver is used. Specific software is created and integrated into the solver to determine the forces applied on the blade surfaces after each iteration. The aerodynamic performance obtained by this hybrid model is compared with experimental data of NREL Phase VI obtained in wind tunnel at NASA Ames. Whereas, the velocity field around the blade airfoil and flow past the rotor are compared with experimental data obtained in this research work in the wind tunnel of Arts et Metiers ParisTech. Further research shows that this model is well suited for the study of flexible wind turbines blades, where it is needed to take into account the fluid-structure interaction. To validate the proposed method for the flexible blades, a study is also conducted for the case of the NREL Phase VI wind turbine. The simulation results are finally compared with experimental data which show the feasibility and effectiveness of the proposed model and the coupling method
Spiegel, Pierre. "Prevision et analyse du bruit emis par un rotor principal d'helicoptere en presence d'interactions pale-tourbillon." Le Mans, 1995. http://www.theses.fr/1995LEMA1022.
Mauffrey, Yann. "Contribution numérique à l'étude des mécanismes aéroacoustiques intervenant dans l'interaction pale-sillage d'un rotor d'hélicoptère." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2008. http://tel.archives-ouvertes.fr/tel-00812470.
Plantin, de Hugues Philippe. "Etude du système tourbillonnaire généré en extrémité de pale d'un rotor d'hélicoptère en vol stationnaire." Aix-Marseille 2, 1991. http://www.theses.fr/1991AIX22051.
Lv, Peng. "Performance aérodynamique et structurelle du rotor flexible pour micro-drones." Thesis, Toulouse, ISAE, 2014. http://www.theses.fr/2014ESAE0058/document.
The wind tunnel tests were conducted to explore the performance difference caused by the potential twist deformation between baseline blades and flexible blades. The balance was built in SaBre wind tunnel for measuring the thrust and torque of blades. The BEMT predictions of blades with varied twist were also performed in hover and forward flight, respectively. In hover,flexible blades cannot help in improving the FM at light disk loading since the twist generated on flexible blades is probably beyond the ideal hover twist. In forward flight, the propulsive efficiency η of flexible blades is mostly higher than baseline blades due to the beneficial twist generated in rotation. A Particle Image Velocimetry (PIV) approach of loads determination was developed based on control volume method to obtain thrust and torque of small-scale proprotor,especially for off-optimum conditions. The pressure Poisson equation was implemented for the pressure estimation based on the PIV velocity data. The axial velocity of flexible blades is found to be lower than baseline blades on the same station at downstream. This corresponds to the lower inflow ratio distribution along flexible blade, which results from the negative twist deformation. For both baseline blades and flexible blades, the thrust differences between PIV test 2 and balance are larger when compared to the differences between PIV test 1 based on nearfield and balance. The Laser Displacement Sensor (LDS) technique was employed for measuring the stationary deformation of rotating flexible blades. By obtaining the LDS point cloud, the bending and torsion of the rotating blade were identified using the multiple regressions
Rahier, Gilles. "Modelisation de l'interaction profil-tourbillon et application au rotor d'helicoptere. Contribution a la prevision du bruit d'interaction pale-tourbillon." Paris 6, 1996. http://www.theses.fr/1996PA066350.
Sánchez, Jiménez Oscar. "On the stochastic response of rotor-blade models with Floquet modal theory : applications to time-dependent reliability of tidal turbine blades." Electronic Thesis or Diss., Normandie, 2023. http://www.theses.fr/2023NORMIR39.
The response of a deterministic rotating mechanical system under stochastic excitation is studied. A mechanical-probabilistic model is developed to combine the relevant characteristics of both aspects of the study: the behavior of this non-standard class of mechanical system and the random properties of correlated stochastic fields describing load processes. The results are applied to a reliability analysis of a reduced order model of a tidal turbine. Semi-analytic and empirical ( in the Monte-Carlo simulation sense) results are obtained, compared and contrasted. The results are framed with respect to the existing literature, and it is found that they provide an innovative treatment of the problem, in terms of the dynamical choices reflected in the model, in the presentation and interpretation of the modal aspects of the system, and in the type of stochastic inputs considered. We develop a dynamical model describing a broad class of mechanical system that models a rotor-blade structure. The model is informed by careful consideration of previous results, with the aim of constructing a reduced model that captures essential characteristics of the vibratory behavior of the structure. Lagrangian formalism is utilized to obtain the equations of motion. The presence of elastic components, which are discretized in a modal way, results in a system of ordinary differential equations with periodic coefficients. The Floquet theory of Linear time-periodic systems is applied on the deterministic dynamical model to synthesize an extension of traditional modal analysis to systems with periodic coefficients. The response of the system is formulated in terms of Floquet exponents and the associated Floquet periodic eigenvectors, from which the Floquet State Transition Matrix can be obtained. Several methods are applied to the modal study of the system, and a new time-frequency approach is proposed based on PGHW wavelets and its associated scalogram. Using an innovative notation to describe probabilistic moments of stochastic quantities, a moment propagation scheme is presented and exploited. The advantages of the treatment, particularly in the case of spatio-temporal stochastic fields, is in its applicability and systematic structure of development. This moment propagation strategy is coupled with a maximum entropy formulation to reconstruct the probability density function of the response and obtain important descriptors of the response, such as the Extreme Value Distribution. The moment propagation technique presented is applied to nonstationary processes. The results from Modal Floquet theory are integrated into this analysis. The problem of crossings of a certain threshold is considered for this type of nonstationary stochastic process. Their response is shown to yield a time-dependent reliability problem, which is resolved using the estimated EVD and then by numerical simulation
DEPARIS, MICHEL. "Application d'une technique de mesure basee sur la velocimetire laser embarquee a l'etude de la couche limite developpee sur une pale de rotor d'helicoptere." Aix-Marseille 2, 1998. http://www.theses.fr/1998AIX22072.
Romagnoli, Matteo. "Sviluppo e integrazione in ambiente di simulazione di modelli tridimensionali per la rappresentazione grafica della dinamica di velivoli ad ala rotante." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
Jin, Xin. "Construction d'une chaîne d'outils numériques pour la conception aérodynamique de pales d'éoliennes." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0099/document.
This Ph.D. thesis presents some research work on aerodynamics of wind turbine blades, in order to dispose a conception chain necessary for different problems, which cannot be treated by one unique method. A simplified numerical toolkit (VALDAG) has been developed to optimize the performance of blades in different creteria. The simulation module use the Generalized Actuator Disc model, which relies on the solution of Navier-Stokes equations and completed with empiric corrections. This tool respects a reasonable compromise between model complexity and computational reliability. An automatic calibration mechanism was implemented using the Nelder-Mead Simplex algorithm. A web users interface (WUI) is also available to adapt VALDAG for industrial engineers. Optimization is then carried on by modifying the blades’ geometry parameters and the designs optimized is stocked in files which can be used for 3D simulation and/or visualization. The blade designed with VALDAG are then simulated by a 3D numerical tool to validate previous predictions. This 3D tool called NaSCar 3D is developed in INRIA and resolve Navier-Stokes equations on to a cartesian mesh, in which the immersed obstacles are considered with the Level-Set function and the penalization method. After some necessary adaptation for the treatment of blades’ geometry, a compromise on CFD configuration is found to simulate a wind turbine rotor. To conclude, this design toolkit VALDAG is low time-costly, user-friendly and efficient. Associated with 3D simulations, a conception chain has been established
Ramos, José. "Méthodologie basée sur la vélocimétrie laser pour l'étude de l'écoulement autour de surfaces portantes en rotation : application à la détermination des efforts locaux sur une pale de rotor en vol stationnaire." Aix-Marseille 2, 1995. http://www.theses.fr/1995AIX22105.
Tixadou, Etienne. "Optimization of the blade structure for minimum dynamic hub loads." Electronic Thesis or Diss., Institut polytechnique de Paris, 2023. http://www.theses.fr/2023IPPAX023.
The general objective of the PhD is to define methods for calculating the hub dynamic loads at the frequency n / rev at the head of the rotor, which are reliable and applicable in a context of industrial development in order to be able to act on the design of the blade. . The methodology is potentially applicable to a main rotor or to new configurations with propellers or multirotors. The scientific lock to be lifted is to be able to optimize a rotor, not on frequency mode placement criteria either but directly on the harmonic shear forces at the foot of the blade. More than the search for absolute precision, it is a question of being able to compare and orient the designs by playing on the different parameters defining the stiffness and mass distribution characteristics. This research work focuses on the development of an automated aeroelastic optimization based on STORM simulations and a discrete genetic algorithm. This approach allows to reduce drastically the time of the blade design process and results in significant dynamic loads reduction on the targeted flight case with respect to the industrial manufacturability constraints
BAMDAD-SOOFI, JAHANSHAH. "Performances mecaniques du rotor d'une eolienne darrieus et application a "aeolia 3" en fonctionnement." Paris, ENSAM, 1986. http://www.theses.fr/1986ENAM0006.
Liu, Zhen. "Conception et analyse aéro-propulsive d'un nanodrone." Toulouse, ISAE, 2011. http://www.theses.fr/2011ESAE0015.
Paris, Manuel. "Identification du comportement en torsion à fort facteur d’avancement des pales d’hélicoptère conventionne : application à la réduction des efforts de commandes sur une formule hybride haute vitesse de type X3." Thesis, Paris, ENSAM, 2014. http://www.theses.fr/2014ENAM0045.
Nowadays, the increase of cruise speed for conventional helicopters (main rotor and anti-torque rear rotor) reaches an asymptote. The X3 concept proposed by Airbus Helicopters is a hybrid helicopter combining 2 propellers at the tip of small wings in order to unload the main rotor. This solution is economically viable because it reuses well-proven technologies such as the Spheriflex rotor, already used on the Dolphin family for many years. X3 flight tests have shown a good behavior of the rotor concerning performances as well as handling qualities, but control loads in the rotor system were significantly higher in cruise conditions than for conventional helicopters. In order to save the payload, over-sizing of the mechanical parts in order to withstand these loads can't be an appropriate solution. The work presented in this thesis deals with the problematic of control loads reduction.In order to reduce the control loads, the first step is to highlight the roots of these loads and to get a predictive tool over the whole flight domain. Experimental measurements from X3 flight tests give the aerodynamic loads on the blade sections, leading to understand the blades torsional dynamic behavior in several flight test cases (cruise, turns and high speed flight). Phenomena responsible for the increase of control loads are then identified, and the rotor computation tool HOST used at Airbus Helicopters is corrected to predict accurately control loads over the conventional as well as the high speed helicopter flight domain.The corrected rotor computation tool HOST, associated with the physical comprehension of the blade torsional dynamics, is used to quantify the possible solutions proposed for control loads reduction. Two main ways are studied: the optimization of the control system architecture and the reduction of pitch link loads. The optimization of control system architecture shows a dramatic reduction of control loads in the servo actuators and in the non-rotating scissors, thanks to an optimization algorithm developed during this thesis. The reduction of pitch link loads study shows that the optimization of the helicopter equilibrium leads to drastic reduction, whereas the modification of blade design does not show any significant reduction even at high speed
Astorri, Pietro. "Prototipazione e stampa 3D degli stadi di un compressore assiale con diverso design." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Dobrev, Ivan. "Modèle hybride de surface active pour l'analyse du comportement aérodynamique des rotors éoliens à pales rigides ou déformables." Phd thesis, 2009. http://pastel.archives-ouvertes.fr/pastel-00005623.