With the growing need to meet aggressive emissions targets in the aerospace industry in the coming decades, the electrification of propulsion systems has become an area of great research and commercial interest. In order to achieve full electrification of larger commercial aircraft, it is critical to improve power and energy densities of components within the propulsion system. The power densities of electric motors are steadily rising to meet this requirement. Among the various motor designs available, the high-speed radial flux permanent magnet motor is presented as an architecture capable of achieving high efficiencies and power densities. Increasing power densities, however, poses challenges for the thermal management system as higher losses need to be dissipated from a relatively small machine package. One of the failure modes specific to permanent magnet motors is the demagnetization of the magnets in the rotor at higher temperatures which leads to a loss in performance. Therefore it is critical that the thermal management system of the rotor must effectively dissipate the losses generated in the magnets and other components within the rotor. This thesis discusses the mechanical and thermal design of a 150 kW high-speed radial flux surface mounted permanent magnet motor for aerospace propulsion applications. The thesis first introduces the current landscape of aerospace electrification, focusing specifically on electric and hybrid propulsion architectures, currently available electric motors for aerospace propulsion, and ongoing aircraft electrification projects. A review is then provided of the current state-of-the-art in rotor cooling designs for high-speed speed radial flux motors for traction applications before introducing the design of the motor proposed in this thesis. The discussion of the mechanical design provides a high level overview of the design, manufacturing, and assembly of the stator and rotating assemblies while the thermal design provides a brief overview of the stator cooling design and a deep dive on the rotor cooling design. Computational Fluid Dynamics (CFD) is used along with the Taguchi method for robust design to optimize the rotor cooling design for minimizing the magnet temperatures. Analysis for the optimized rotor cooling discussed is provided before providing recommendations for future work. / Thesis / Master of Applied Science (MASc)

Cascade testing and flow analysis of three high-turning supercritical compressor blades were conducted. The blades were designed at an inlet Mach number (M1) of 0.87 and inlet flow angle of 48.4 deg, with high camber angles of about 55 deg. The baseline blade was a conventional Controlled Diffusion Airfoil (CDA) design and the other two were optimized blades. The blades were tested for an inlet Mach number range from 0.61 to 0.95 and an inlet flow angle range from 44.4 deg to 50.4 deg, at high Reynolds numbers (1.2-1.9x10^6 based on the blade chord). The test results have shown lower losses and better incidence robustness for the optimized blades at higher supercritical flow conditions (M1>0.83). At the design condition, 30% loss reduction was achieved. The blade-to-blade flow was computed by solving the two-dimensional steady Navier-Stokes equations. Experimental results, in conjunction with the CFD flowfield characterization, revealed the loss reduction mechanism: severe boundary layer separation occurred on the suction surface of the baseline blade while no separation occurred for the optimized blades. Furthermore, whether the boundary layer was separated or not was found due to different shock patterns, different shock-boundary layer interactions and different pressure distributions on the blades. For the baseline blade, the strong passage shock coincided with the adverse pressure gradient due to the high blade front camber at 20% chord, leading to the flow separation. For the optimized blades, the high blade camber shifted to more downstream (30-40% chord), resulting in stronger flow leading edge acceleration, less strength of the passage shock near the blade surface, favorable pressure gradient right after the passage shock, thus no flow separation occurred. The flow understanding obtained by the current research can be used to guide the design of high-turning compressor blades at higher supercritical flow conditions. / Ph. D.

The effects of trailing edge flow control on the wakes of a linear cascade of idealized fan blades was investigated experiments with a view to the likely effects on broadband aircraft engine interaction noise. Single and three-component hotwire velocity measurements were made downstream of the cascade for a chord Reynolds number of 390,000 and a Mach number of 0.07. Measurements of the two-point velocity correlation were used extensively to evaluate the impact of various flow control strategies on the organization of the coherent structures of the wakes and their potential to generate noise. A baseline flow was established by measuring the wake downstream of unmodified GE-Rotor-B blades. Four sets of serrated trailing edge blades (with two different serration sizes and with two trailing edge cambers) and three sets of blades with trailing edge blowing (a simple rectangular slot, rectangular slot with Kuethe-vane vortex generators, and rectangular slot with serrated lips) were tested. The serrated trailing edges introduce corrugations into the wake, increase the wake decay and width as well as turbulence levels (possibly because of the blunt trailing edge created at the serration valley). The serrated trailing edges also increase the turbulence scales in the direction perpendicular to the plane of the wake because of the injection of streamwise vorticity. In almost all cases the serrations reduce the spanwise and streamwise turbulence scales. Serrations do not, however, affect the apparent time scale of quasi-periodic structures in the wake, and this appears to limit the potential of this trailing edge treatment to reduce broadband noise. The analysis of the characteristic eddies (obtained from proper orthogonal decomposition combined with linear estimation) revealed that the serrations do not change the qualitative form of the eddies. Trailing edge blowing was found to significantly decrease the wake deficit and width as well as the turbulence levels at all blowing rates. Blowing through the simple rectangular slot, at mass flow rates between 1.4 and 2.0% of the total passage through flow, was shown to significantly affect the size, the organization and the strength of the coherent structures. For small blowing rates the strong spanwise eddies near the trailing edge actually appear to be enhanced. For larger blowing rates, however, the turbulent scales are reduced in all directions. The addition of Kuethe vanes on the suction side of the blowing blade results in a low momentum region just downstream of the vanes that may result from flow separation there. This further enhances the shedding and increases the blowing rate needed to overcome it. The serrated blowing blades show the greatest potential to reduce broadband noise as they reduce the turbulence levels and scales without creating potentially detrimental structures. While no acoustic measurements were made, analysis of hypothetical perpendicular and parallel interactions of blades with these wakes has made possible to characterize for the first time the impact of the changes in the eddy structure of these wakes on their potential to generate broadband noise. The serrated trailing edges (especially the larger serrations) actually increase the potential of the wake to generate broadband noise (a direct consequence in the overall increase in turbulence scale and intensity). In contrast, every trailing edge blowing configuration was found to produce large reductions in the potential noise (a maximum of 6dB reduction was obtained at 2.0% blowing). The addition of Kuethe vanes on the suction side of the blowing blades significantly reduced the efficiency of the simple blowing configuration (a result of the increased coherency associated with the shedding of streamwise vorticity by the vanes). The serrated blowing configuration was found to yield reductions similar to the simple blowing configuration. / Ph. D.

A series of experiments were conducted in a F109 turbofan engine to investigate the unsteady wake profiles of an Inlet Guide Vane (IGV) at a typical spacing to the downstream fan at subsonic and transonic relative blade velocities. The sharp trailing-edge vanes were designed to produce a wake profile consistent with modern IGV. Time averaged baseline measurements were first performed with the IGV located upstream of the aerodynamic influence of the fan. Unsteady experiments were performed with an IGV-fan spacing of 0.43 fan chords. High-frequency on-vane pressure measurements showed strong peak-to-peak amplitudes at the blade passing frequency (BPF) of 4.7 psi at the transonic fan speeds. High-frequency total pressure measurements of the IGV wake were taken between the IGV and fan. Results showed that the total pressure loss coefficient of the time averaged IGV wake is reduced by 30% for the subsonic fan, and increased by a factor of 2 for the transonic fan compared to the baseline. Time resolved wake profiles for subsonic fan speeds show constructive and destructive interactions over each blade pass generated by the fan potential flow field. Time resolved wake profiles for the transonic fan speeds show that shock interactions with the IGV surface result in the wake shedding off of the vane at the BPF. Furthermore, the effectiveness of trailing edge blowing (TEB) flow control was investigated. TEB is the method of injecting air aft of the IGV to reduce the low pressure regions (deficits) in the viscous wakes shed by the vanes. Minimizing the IGV wakes reduces the forcing function on the downstream fan blades, thereby reducing high cycle fatigue. The TE span of the vane contains discrete holes at the axial centerline for TEB. Baseline results showed that TEB eliminates the IGV wake, while using only 0.03% of the total engine mass flow per IGV. TEB for the subsonic fan at the close spacing shows complete wake filling using the same mass flow as the baseline. TEB for the transonic fan shows a reduction of 68% in the total pressure loss coefficient, while requiring 2.5 times the mass flow as the baseline. / Ph. D.

An innovative application of existing technology is proposed for attenuating the effects of transient phenomena, such as rotor-stator and rotor-strut interactions, linked to noise and fatigue failure in turbomachinery environments. A computational study was designed to assess the potential of Passive Porosity Technology as a mechanism for alleviating interaction effects and radiated noise by reducing the fluctuating forces acting on the vane surfaces. The study involved a typical high bypass fan stator airfoil immersed in a subsonic free field and exposed to the effects of a transversely moving wake. Time histories of the primitive aerodynamic variables obtained from Computational Fluid Dynamics (CFD) calculations were input into an acoustic prediction code to estimate noise levels at a radial distance of ten chords from the stator airfoil. This procedure was performed on the solid airfoil to obtain a baseline, and on approximately fifty porous configurations in order to isolate those that would yield maximum noise reductions without compromising the aerodynamic performance of the stator. It was found that, for a single stator immersed in a subsonic flow field, communication between regions of high pressure differential - made possible by the use of passive porosity - tends to induce a time-dependent oscillatory pattern of small inflow-outflow regions near the stator leading edge (LE), which is well established before wake effects come into play. The oscillatory pattern starts at the LE, and travels downstream on both suction and pressure sides of the airfoil. The amplitude of the oscillations seemed to be proportional to the extension of the porous patch on the pressure side. Regardless of this effect, which may not have occurred if the airfoil were placed within a stator cascade, communication between regions of high pressure differential is necessary to significantly alter the noise radiation pattern of the stator airfoil. Whether those changes result in noise abatement or enhancement depends primarily on the placement and extension of the porous patches. For most viable configurations, porosity reduced loading noise but increased thickness noise. Variations in nominal porosity were of secondary importance. In general, the best aerodynamic performers (i.e., those configurations that were able to reduce unsteady lift without severely altering the lift and/or drag characteristics of the solid airfoil) were also the best acoustic performers. As a result of using passive surface porosity, overall peak radiated noise was reduced by approximately 1.0 dB. This reduction increased to about 2.5 dB when the effects of loading noise alone were considered. / Ph. D.

Le bruit tonal d’interaction rotor-stator, généré par l’impact des sillages issus des pales d’un rotorsur la grille d’aubes d’un stator redresseur, contribue de manière déterminante au bruit d’origineaérodynamique des turbomachines axiales carénées, qui équipent une large part des systèmes de propulsionaéronautique et de conditionnement d’air. La prédiction du bruit par l’utilisation de simulationsnumériques demeure onéreuse, notamment dans les premières phases de conception lorsque de nombreusesconfigurations doivent être testées. Dans cette optique, l’approche analytique choisie dans cettethèse apporte une alternative tout à fait appropriée. Les modèles analytiques basés sur une fonctionde réponse aéroacoustique de profil isolé ne permettent pas de reproduire l’effet de grille engendrépar le nombre important d’aubes de stator. Inversement, de fortes approximations sont nécessairespour décliner les fonctions de réponse de grilles d’aubes existantes dans des configurations tridimensionnelles.Le formalisme proposé, basé sur la méthode de raccordement modal, permet d’introduiresimplement l’effet de grille dans une géométrie annulaire d’étage rotor-stator. Un modèle de réponse degrille rectilinéaire bidimensionnel est tout d’abord présenté pour la transmission d’ondes acoustiques àtravers le stator ainsi que pour la génération de bruit par l’impact de rafales hydrodynamiques. Dansce cadre, une analyse linéaire et non visqueuse est considérée, pour laquelle les modes acoustique ettourbillonnaire d’un gaz sont couplés par le biais des frontières rigides. Les perturbations de vitessesliées aux sillages sont modélisées comme des rafales convectées. Leur impact sur la grille de statorgénère des ondes acoustiques se propageant en amont, en aval ainsi que dans les espaces inter-aubesdu stator, vu comme un réseau périodique de guides d’ondes. Les sections de bords d’attaque et defuite des aubes sont considérées comme des interfaces sur lesquelles la continuité des fluctuations depression, de vitesse axiale et de vorticité est vérifiée. Un système d’équations est ainsi obtenu, puisrésolu par des projections sur les bases modales du conduit et des inversions matricielles. Le champacoustique rayonné est ainsi déterminé uniformément dans tout le domaine. Les résultats issus de cesmodélisations sont comparés à ceux des fonctions de réponse de grilles d’aubes rectilinéaires issues dela littérature, montrant un très bon accord avec les modèles basés sur la technique de Wiener-Hopf. Leformalisme est par la suite étendu aux grilles annulaires par l’ajout de fonctions de Bessel comme fonctionsde forme radiale exprimant les effets tridimensionnels. Finalement, une procédure est présentéepour rendre compte de l’hétérogénéité des aubes de stator, caractéristique des nouvelles architecturesde turbomachines. Cette méthodologie est basée sur l’emploi conjoint du principe du dipôle de bordd’attaque et de la fonction de réponse aéracoustique de la grille de stator à l’aide de la technique deraccordement modal. Le principe de dipôle de bord identifie le chargement instationnaire des aubesinduit par l’impact de rafales hydrodynamiques, calculé par le formalisme d’Amiet, avec la trace duchamp de pression acoustique produit par un dipôle placé au voisinage du bord de l’aube. Les prédictionsissues de ce modèle, appliqué dans un cadre bidimensionnel, sont ensuite comparées à des mesuresobtenues pendant la campagne d’essais du projet SEMAFOR. / The rotor-stator wake-interaction tonal noise, generated by the impingement of rotor wakes onoutlet guide vanes, plays a crucial role in the aerodynamic noise of axial-flow ducted fan stages. Thelatter are widely used in most aeronautic propulsion and air-conditioning systems. The noise predictionby means of numerical simulations remains expensive, especially at the preliminary design stage whennumerous configurations must be tested. In this respect, the analytical approach chosen in this thesisprovides a well suited alternative. The analytical modeling based on an isolated-airfoil response functioncan not reproduce the cascade effect introduced by the large number of stator vanes. Conversely, drasticapproximations are required to extend the current cascade response functions to three-dimensionalconfigurations. The proposed modeling based on the mode-matching technique simply introduces thecascade effect in an annular rotor-stator stage. A rectilinear cascade response function is firstly presentedto account for the acoustic transmission through the stator along with the wake-interaction noise.In this context, a linearized and non-viscous analysis is carried out, in which the acoustic and vorticalmodes of a gas are coupled at rigid physical boundaries. The velocity perturbations issued from thewakes are written as a sum of convected gusts. Their impingement on the cascade of vanes generatesacoustic waves propagating upstream, downstream of the cascade, as well as inside the inter-vane channelsof the stator, seen as a periodic array of bifurcated waveguides. The duct cross sections at theleading-edge and the trailing-edge of the vanes are seen as interfaces on which the continuity of thefluctuating pressure, axial velocity and vorticity is fulfilled. A system of linear equations is obtained,then solved by means of modal projections and matrix inversions. The acoustic field is then uniformlycalculated in the whole domain. Comparisons with rectilinear cascade response functions show a verygood agreement with predictions based on the Wiener-Hopf technique. The configuration of an annularcascade is addressed by introducing the Bessel functions as radial shape functions, expressing threedimensionaleffects. Finally, a procedure is presented to account for the heterogeneity of the statorvanes, typical of modern fan architectures. This approach is based on the combinaison of the leadingedgedipole principle and the cascade response function derived from the mode-matching technique.The edge-dipole principle identifies Amiet’s solution for the unsteady loading and the radiation of adipole approached very close to the edge of a half plane. The predictions provided by this modeling,applied in a two-dimensional configuration, are finaly compared to measurements performed in the testcampaign of the SEMAFOR project.

During the insert process when the windings of an electric motor are pushed into the stator slots, some detrimental phenomena can occur that affect the efficiency and life of the motor. To detect these phenomena and optimize the process, a simulation would be useful. An investigation of the possibility to perform a simulation, using an appropriate numerical method for the insert process of distributed windings in a permanent magnet synchronous motor, was performed. During the project, a literature study was carried out to investigate existing methods and key-parameters for the simulation of the process. Explicit finite element method has been shown to be a suitable numerical method for simulating another winding process. An explicit finite element analysis was performed with a simplified model of the stator, the wires, the transmission tool and the needles by using the software Abaqus/CAE. In order to reduce the computational time, beam elements were used to model the wires and the other parts as rigid bodies. The model accounted for example contact and provided numerical results. The result was a suitable model. However, it needs to be developed further.

Les ensembles turbo-alternateurs des centrales électriques sont de grandes machines tournantes de plus de 50 mètres de long et de plusieurs centaines de tonnes. Lors du fonctionnement normal d'une telle machine, une probabilité non nulle existe d'un détachement accidentel d'une aube. Dans une telle situation, un balourd important est généré et du contact apparaît entre les parties tournantes et non tournantes de la machine. Il est alors capital de pouvoir simuler efficacement la dynamique de ce type d'évènement faisant intervenir de fortes non linéarités dans le système. Cette thèse a été réalisée dans le cadre du projet ANR (Agence Nationale de la Recherche) IRINA (SImulation et maîtRise des rIsques en coNception des mAchines tournantes) et en particulier entre le LaMCoS (LAboratoire de Mécanique des Contacts et des Structures) de l'INSA de Lyon et le département AMA (Analyses Mécaniques et Acoustiques) d'EDF R et D à Clamart. Elle a pour objectif de mettre au point une technique rapide de simulation du comportement des lignes d'arbres de machines tournantes en cas de présence de non linéarité de type contact entre rotor et stator. Pour atteindre cet objectif, une double démarche a été mise en place. La première consiste à mettre au point des modèles simplifiés afin de réduire le nombre de degrés de liberté du problème. De surcroît, une technique de réduction de modèle adaptée au cas de non linéarité localisée est utilisée afin de réduire encore plus la taille du système à résoudre. La seconde démarche consiste à mettre au point une technique de résolution rapide du système réduit afin d'obtenir la solution encore plus rapidement. Pour cela, au lieu d'utiliser les traditionnelles techniques d'intégration temporelle directe, c'est la méthode de la balance harmonique qui est mise à profit. Cette technique permet d'obtenir directement la réponse stabilisée du système grâce à une résolution des équations dans le domaine fréquentiel. Dans ce cadre, une maquette numérique a été mise au point mettant en oeuvre les fonctionnalités citées. Cette dernière permet de reproduire les phénomènes physiques périodiques ainsi que quasi-périodiques et de déterminer leur stabilité. Des études paramétriques sur des exemples de problèmes de contact rotor-stator viennent illustrer cette démarche. Enfin, une application sur un cas industriel de groupe turbo alternateur EDF est présentée. / Power plants turbo-generator sets are large rotating machines of more than 50 meters long and weight several hundred tons. During normal operation of such a machine, there is a nonzero probability of an accidental disconnection of a blade. In such a situation, a significant imbalance is generated and contact may occur between the rotating and non-rotating parts. It is therefore essential to be able to effectively simulate the dynamics of this type of event involving strong nonlinearities in the system. This PhD was conducted within the framework of the ANR (Agence Nationale de la Recherche) IRINA (Simulation and risk control in rotating machinery design) and in particular between the LaMCoS (LAboratory of Contact Mechanics and Structures) of the INSA Lyon and the AMA department (Mechanical and Acoustic Analysis) at EDF R and D in Clamart. It aims to develop a fast technique for simulating the behavior of shafts of rotating machinery in case of presence of non-linearity of contact between rotor and stator. To achieve this goal, a dual approach was implemented. The first is to develop simplified models to reduce the number of degrees of freedom of the problem. In addition, a model reduction technique suitable for the case of localized nonlinearity is used to further reduce the size of the system to be solved. The second approach is to develop a technique for efficient resolution of the reduced system to obtain the solution more quickly. To do this, instead of using the traditional direct temporal integration techniques, the harmonic balance method is put to use. This technique allows to directly obtain the stabilized response of the system thanks to a resolution of the equations in the frequency domain. In this context, a numerical model has been developed to implement the features mentioned. The latter allows to reproduce the physical periodic and quasi-periodic phenomena and to determine their stability. Parametric studies of examples of problems of rotor-stator contact will illustrate this approach. Finally, an application on an industrial case of turbo generator EDF is presented.

Ce travail est le produit d’une collaboration entre le LMFA (Laboratoire de Mécanique des Fluides et d’Acoustique, École Centrale de Lyon – France), Snecma et le Cerfacs. Il vise à étudier l’écoulement se développant dans le compresseur haute-vitesse axial de 3.5 étages CREATE (Compresseur de Recherche pour l’Etude des effets Aérodynamique et TEchnologique – vitesse de rotation : 11543 tr/min, vitesse en tête de rotor 1 : 313 m/s), conçu et construit par Snecma et étudié au LMFA sur un banc d’essai de 2 MW. Pour étudier l’écoulement, des mesures stationnaires de pression et température, de la vélocimétrie laser et des mesures rapides de pression statique et totale ont été utilisées. L’analyse se concentre sur deux aspects principaux : l’étude de l’écoulement aux points de fonctionnement stables, avec un intérêt tout particulier pour les interactions rotor-stator, et l’étude des instabilités apparaissant dans la machine à faibles débits.La description de l’écoulement instationnaire aux points stables est faite par le biais de mesures de pression statique en parois, de pression totale et de vitesse, mais également de température totale, entropie et angle d’incidence du fluide. Il est montré que la complexité et l’instationnarité de l’écoulement dans un compresseur multiétagé augmente fortement à l’arrière de la machine à cause des interactions entre les roues fixes et mobiles. Ainsi, une méthode d’analyse modale basée sur la décomposition de Tyler et Sofrin a été développée pour analyser ces interactions. Elle est d’abord appliquée aux mesures de pression afin d’extraire les contributions de chaque roue. Il est ainsi montré que les interactions complexes de pression dans CREATE peuvent être réduites à trois principaux types d’interactions. La méthode de décomposition est enfin appliquée au champ d’entropie dans toute la machine extrait de calculs CFD URANS réalisés par le Cerfacs, afin d’évaluer l’impact des interactions sur les performances de CREATE en terme de génération de pertes.La dernière partie de ce travail est dédié à l’analyse des instabilités apparaissant dans CREATE à faible débit. Il est montré que des ondes de pression tournantes apparaissent aux points stables et augmentent en amplitude à mesure qu’on se rapproche de la ligne de pompage, jusqu’à atteindre une taille critique induisant l’apparition d’une cellule de décollement tournant sur toute la hauteur de veine. Cette cellule entraîne la machine en pompage en seulement quelques tours. L’étude de ces ondes de pression, et la compréhension de leur véritable nature sont réalisées grâce à l’application d’un modèle analytique aux mesures expérimentales. Une description précise du déclenchement et du cycle du pompage est également faite grâce aux mesures de pression statique au dessus des rotors. Un système de contrôle anti-pompage développé au laboratoire et basé sur la détection de l’amplitude des ondes de pression est finalement décrit. / The present work is a result of collaboration between the LMFA (Laboratoire de Mécanique des Fluides et d’Acoustique, Ecole Centrale de Lyon – France), Snecma and the Cerfacs. It aims at studying the flow in the 3.5-stages high-speed axial compressor CREATE (Compresseur de Recherche pour l’Etude des effets Aérodynamique et TEchnologique - rotation speed: 11543 RPM, Rotor 1 tip speed: 313 m/s), designed and built by Snecma and investigated at LMFA on a 2-MW test rig. Steady measurements, as well as laser velocimetry, fast-response wall static and total pressure measurements have been used to experimentally investigate the flow. The analysis focuses on two main aspects: the study of the flow at stable operating points, with a special interest on the rotor-stator interactions, and the study of the instabilities arising in the machine at low mass flow rates.The description of the unsteady flow field at stable operating points is done through measurements of wall-static pressure, total pressure and velocity, but also total temperature, entropy and angle of the fluid. It is shown that the complexity and unsteadiness of the flow in a multistage compressor strongly increases in the rear part of the machine, because of the interactions between steady and rotating rows. Therefore, a modal analysis method developed at LMFA and based on the decomposition of Tyler and Sofrin is presented to analyze these interactions. It is first applied to the pressure measurements, in order to extract the contributions of each row. It shows that all the complex pressure interactions in CREATE can be reduced to three main types of interactions. The decomposition method is then applied to the entropy field extracted from URANS CFD calculations performed by the Cerfacs, in order to evaluate the impact of the interactions on the performance of the machine in term of production of losses.The last part of this work is devoted to the analysis of the instabilities arising in CREATE at low mass flows. It shows that rotating pressure waves appear at stable operating points, and increase in amplitude when going towards the surge line, until reaching a critical size provoking the onset a full span stall cell bringing the machine to surge within a few rotor revolutions. The study of these pressure waves, and the understanding of their true nature is achieved through the experimental results and the use of some analytical models. A precise description of the surge transient through wall-static pressure measurements above the rotors is also provided, as well as a description of a complete surge cycle. An anti-surge control system based on the detection of the amplitude of the pressure waves is finally proposed.

This work is dedicated to increasing the effectiveness of a particular draft induction motor, which was before the change and subjected to laboratory measurements according to EN60034 - 2-1, an analytical calculation of the losses and the overall efficiency and analysis program RMxprt. The first part focuses on the analysis of measurement data, measurement of partial loss in the machine and overall efficiency. In the second chapter, losses and efficiency calculated analytically, in the first case using the links in the professional literature dealing with the design of electric motors and in the second case by a program for the rapid design of rotating electrical machines, RMxprt program. At the end of this chapter all parameters are obtained measurements and calculations are compared. The third chapter is devoted to the calculation of losses and the resulting efficiency machines in a computer program, in which I gradually adopted changes to increase the efficiency of electrical machines. It also shows the calculation of the new dimensions of the stator and rotor slots. In the fourth chapter, the preparation of documentation for the production of a new two-layer winding for the current machine, while preserving the original dimensions of stator slots. The last part is devoted to the analysis of measurement data on the supplied asynchronous motor with a newly designed stator winding. In conclusion then discussed the results of work.