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Relevant bibliographies by topics / Flexible rotor

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Academic literature on the topic 'Flexible rotor'

Author: Grafiati

Published: 28 June 2021

Last updated: 29 May 2022

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Journal articles on the topic "Flexible rotor"

1

Barzdaitis, Vytautas, Vytautas Žemaitis, R. Jonušas, Vytautas Kazimieras Augustaitis, and Vytautas Bučinskas. "Dynamics of a Mechatronic System with Flexible Vertical Rotor." Solid State Phenomena 113 (June 2006): 223–28. http://dx.doi.org/10.4028/www.scientific.net/ssp.113.223.

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The paper is dedicated to research on flexible rotor systems with anisotropic rotor material properties. In addition, the anisotropy of rotor supports alters the rotor system resonance frequencies and the machine has to pass till it attains the operating angular speed. This phenomenon of rotor vibration is observed in vertical rotors. The aim of this work is to compare experimental vibration measurements and results of theoretical modeling. In the paper theoretical model, created from physical one of really existing rotor system is described. Collected experimental data of rotor vibrations in bearings are compared with results of theoretically derived equations. The results of theoretical modeling and research enables for estimation of a more precise technical condition of the rotor system both after the overhaul and during the maintenance and thus to avoid unexpected breakdowns, especially concerning the fatigue development in ball bearing elements.

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Khang, Nguyen Van, and Tran Van Luong. "On a programme for the balancing calculation of flexible rotors with the influence coefficient method." Vietnam Journal of Mechanics 22, no. 4 (December 30, 2000): 235–47. http://dx.doi.org/10.15625/0866-7136/9980.

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This paper presents the influence coefficient method of determining the locations of unbalances on a flexible rotor system and the correction weights. A computer software for calculating the at-the-site balancing of a flexible rotor system was created using C++ language at the Hanoi University of Technology. This software can be used by balancing flexible rotors in Vietnam.

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Maslen, E. H., and P. E. Allaire. "Magnetic Bearing Sizing for Flexible Rotors." Journal of Tribology 114, no. 2 (April 1, 1992): 223–29. http://dx.doi.org/10.1115/1.2920877.

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Magnetic bearing load capacity in flexible rotor systems must be adequate to accommodate external loads acting on the rotor. The first part of this paper develops the theoretical basis for computing the bearing load capacity requirements of flexible rotors subject to bounded external harmonic loads and strict motion constraints. The second part of this work illustrates the application of the theory to a specific example: a fairly simple three disk flexible rotor subject to mass unbalance loads. Load capacity requirements are computed for the example shaft at its first three free-free forward whirl critical speeds. Based on the bounds obtained, two bearing design cases are examined: one with 45 N load capacity and the other with 223 N load capacity. The performance of the rotor is not improved with the higher capacity bearing and neither is capable of adequately constraining the rotor at its second critical speed. It is concluded that this shaft cannot be operated above its second free-free critical speed without a midspan bearing.

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El-Shafei, A., A. S. El-Kabbany, and A. A. Younan. "Rotor Balancing Without Trial Weights." Journal of Engineering for Gas Turbines and Power 126, no. 3 (July 1, 2004): 604–9. http://dx.doi.org/10.1115/1.1762903.

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The traditional balancing methods using trial or calibration weights are quite effective, yet too many trials may result in a lengthy balancing process. It had been suggested in the literature that it is possible to balance flexible rotors without the use of trial weights, if a rotor model is available. A procedure is developed in this paper to balance flexible rotors using complex modes and complex vibration measurements. It is shown that a complex rotor model is essential for the success of the technique. Moreover, careful calibration of the rotor model is the major cornerstone of the procedure. Experimental results illustrate the success of the procedure.

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Ma, Xunxun, Shujia Li, Wangliang Tian, Xiqiang Qu, Shengze Wang, and Yongxing Wang. "Dynamic Behavior Analysis of the Winding Rotor with Structural Coupling and Time-Frequency Varying Parameters: Simulation and Measurement." Applied Sciences 11, no. 17 (September 1, 2021): 8124. http://dx.doi.org/10.3390/app11178124.

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To satisfy the requirements of high speed, large capacity and constant winding, a textile winding rotor needs to work in a wide rotation speed range and frequently pass through critical speed points. Thus, the winding rotor adopts the flexible long shaft coupling structure and flexible support with rubber O-rings. This kind of rotor has a multi-coupling structure and frequency-dependent parameters characteristics, especially representative and universal in the dynamic analysis method of the high-speed rotor. In this paper, an approach was proposed to investigate the dynamic behavior of the winding rotor considering the flexible coupling and frequency-dependent supporting parameters. Firstly, a dynamic model of the winding rotor was established by using a Timoshenko beam element. Its dynamic behaviors were simulated by considering the time-varying rotation speed and the frequency-dependent parameters of flexible support. Secondly, a non-contact measuring device was developed for measuring the vibration displacement of the winding rotor in three different speed-up times. Finally, based on simulation and measurement data, how flexible support parameters and the speed-up time affect the winding rotor passing through the critical speed point of the rotor smoothly is revealed. The methods and findings reported here can be used for theoretical and experimental vibration analysis of other types of high-speed flexible rotors.

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Muhammed Ameen, Yahya, and Jaafar Khalaf Ali. "Flexible rotor balancing without trial runs using experimentally tuned FE based rotor model." Basrah journal of engineering science 21, no. 1 (February 1, 2021): 20–26. http://dx.doi.org/10.33971/bjes.21.1.4.

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A method based on experimentally calibrated rotor model is proposed in this work for unbalance identification of flexible rotors without trial runs. Influence coefficient balancing method especially when applied to flexible rotors is disadvantaged by its low efficiency and lengthy procedure, whilst the proposed method has the advantage of being efficient, applicable to multi-operating spin speeds and do not need trial runs. An accurate model for the rotor and its supports based on rotordynamics and finite elements analysis combined with experimental modal analysis, is produced to identify the unbalance distribution on the rotor. To create digital model of the rotor, frequency response functions (FRFs) are determined from excitation and response data, and then modal parameters (natural frequencies and mode shapes) are extracted and compared with experimental analogies. Unbalance response is measured traditionally on rotor supports, in this work the response measured from rotating disks instead. The obtained results show that the proposed approach provides an effective alternative in rotor balancing. Increasing the number of balancing disks on balancing quality is investigated as well.

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Zaytsev, Nikolay, Denis Zaytsev, Andrey Makarov, and Dmitriy Mineev. "NUMERICAL SIMULATION OF THE DYNAMICS OF A FLEXIBLE ROTOR WITH TWO BALL AUTO-BALANCERS." Perm National Research Polytechnic University Aerospace Engineering Bulletin, no. 62 (2020): 31–44. http://dx.doi.org/10.15593/2224-9982/2020.62.04.

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Ball auto-balancing devices can to compensate changes of unbalance "on the move" only for rotors operating at supercritical speeds. For automatic balancing of such rotors, classified as flexible rotors, several auto-balancers located in different cross sections of the shaft are necessary. This makes it necessary to account bending fluctuations on studies of dynamics of the rotor with auto-balancers, that is especially important in the design of the real rotors. In view of the complexity of experimental studies of such rotors in the article the method of direct numerical simulation of the dynamics of the flexible rotor system – supports – auto-balances is considered. The methodological basis of this method is the use of a discrete multi-mass rotor model, which is equivalent in dynamic characteristics to a real rotor, and also the equations of dynamics of the system discrete rotor – supports – auto-balancers, obtained in the direct form of recording. For definition of discrete masses and a matrix of coefficients of influence of stiffness of rotor cross-sections it is supposed to use calculations for finite-element model of a real rotor by existing software complexes of the engineering analysis. The mathematical model of the system dynamics obtained by the Lagrange method takes into account the non-stationarity of the rotor rotation speed, the influence of gravity and the rolling friction of the balls in the auto-balancer cages. Verification of the mathematical model was performed by reproducing the published data using a computational model for a two-support single-disk three-mass rotor with a two-ball auto-balancer. For a four-mass rotor with two two-ball auto-balancers, the results of numerical simulation of dynamics for the modes of acceleration, steady-state rotation and deceleration are presented. It is shown that for the system under consideration, only partial auto-balancing takes place in the steady rotation mode, including after a stepwise increase of the imbalance.

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Halder, B., A. Mukherjee, and R. Karmakar. "Theoretical and Experimental Studies on Squeeze Film Stabilizers for Flexible Rotor-Bearing Systems Using Newtonian and Viscoelastic Lubricants." Journal of Vibration and Acoustics 112, no. 4 (October 1, 1990): 473–82. http://dx.doi.org/10.1115/1.2930131.

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A combination of a squeeze film damper and a plane journal bearing is studied as a stabilizing scheme. The damper is made to play the role of a stabilizer to postpone the instability threshold speeds of flexible rotors. Both Newtonian and viscoelastic fluids are used in the rotor-bearing system. Dynamics of the system is theoretically analyzed using bond graphs. Analysis reveals that the use of a Newtonian fluid in the stabilizer largely improves the high speed stability range. However, viscoelastic stabilizing fluid has a detrimental effect on highly flexible rotors. Experimental investigations, conducted on a flexible rotor (natural frequency, 30 Hz), confirm the theoretical findings. In addition, experiments indicate that though the use of viscoelastic stabilizing fluids leads to instability in flexible rotors, the growth of large amplitude whirl is postponed to very high speeds.

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Smalley, Anthony J. "Jørgen Lund: A Perspective on His Contributions to Modern Rotor Bearing Dynamics." Journal of Vibration and Acoustics 125, no. 4 (October 1, 2003): 434–40. http://dx.doi.org/10.1115/1.1605765.

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This paper presents a perspective on the work of Dr. J. W. Lund, in the field of rotor-bearing dynamics. It traces his most influential work in published journals, software, data published in various manuals, government reports, and course notes. It addresses his work in oil bearings, gas bearings, unbalance response of flexible rotors, stability of flexible rotors, squeeze-film dampers, rotor balancing, and modal testing of rotors. It provides a road map for those who would revisit the knowledge base. It shows how Dr. Lund’s work has permeated the practice of today’s suppliers and users of turbomachinery, and industry consultants.

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Keogh, P. S., and M. O. T. Cole. "Rotor vibration with auxiliary bearing contact in magnetic bearing systems Part 1: Synchronous dynamics." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 217, no. 4 (April 1, 2003): 377–92. http://dx.doi.org/10.1243/095440603321509676.

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Magnetic bearing systems incorporate auxiliary bearings to prevent physical interaction between rotor and stator laminations. Rotor/auxiliary bearing contacts may occur when a magnetic bearing still retains a full control capability. To actively return the rotor to a non-contacting state it is essential to determine the manner in which contact events affect the rotor vibration signals used for position control. An analytical procedure is used to assess the nature of rotor contact modes under idealized contacts. Non-linearities arising from contact and magnetic bearing forces are then included in simulation studies involving rigid and flexible rotors to predict rotor response and evaluate rotor synchronous vibration components. An experimental flexible rotor/magnetic bearing facility is also used to validate the predictions. It is shown that changes in synchronous vibration amplitude and phase induced by contact events causes existing controllers to be ineffective in attenuating rotor displacements. These findings are used in Part 2 of the paper as a foundation for the design of new controllers that are able to recover rotor position control under a range of contact cases.

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Dissertations / Theses on the topic "Flexible rotor"

1

Lim, Chin Lee. "Non-linear performance in flexible rotor system." Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423004.

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Viana, Serra Villa Cristiano Thouverez Fabrice. "Dynamique non linéaire des rotors Applications numériques et expérimentales à un rotor flexible /." [S.l.] : [s.n.], 2005. http://bibli.ec-lyon.fr/exl-doc/cvilla.pdf.

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Viana, Serra Villa Cristiano. "Dynamique non linéaire des rotors : Applications numériques et expérimentales à un rotor flexible." Ecully, Ecole centrale de Lyon, 2005. http://bibli.ec-lyon.fr/exl-doc/cvilla.pdf.

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Cette thèse s'intéresse au comportement dynamique des machines tournantes comportant des organes tels que des roulements dont le fonctionnement est décrit par des lois non linéaires. Le premier objectif de ces travaux de recherche est de mettre en oeuvre des méthodes d'analyse non linéaire afin de résoudre les équations du mouvement de tels systèmes tournants. Le second objectif consiste à effectuer des études expérimentales sur un rotor flexible et d'effectuer des corrélations avec les modèles numériques associés. La modélisation des parties linéaires du système tournante est faite par la méthode des éléments finis. Concernant les roulements, nous présentons trois modèles permettant de prendre en compte leurs non-linéarités intrinsèques telles que le jeu radial et le contact de Hertz. Nous nous intéressons alors plus particulièrement à une modélisation où la cinématique des éléments roulants est considérée. Le type de solution non-linéaire recherchée est le régime permanent
This thesis deals with the dynamic behavior of rotating machinery containing the parts whose behavior is described by non linear laws. The first goal of this research is to implement methods of non linear analysis in order to solve the equations of motion of the system. Secondly, experimental studies are made with a test rig and the results are used to update a numeric model. The rotor is represented by a finite element model. To model the bearings, three models with different levels of complexity are presented, and a model where the kinematics of the rolling elements is adopted. The type of motion of interest is the steady state vibration, and to obtain this kind of solution it is advisable to use a frequential method like the Harmonic Balance Method Alternating Frequency Time (HBM AFT). This method can be implemented with an exact condensation strategy to reduce the computational time. The HBM AFT method is validated by comparing with a direct integration of a non linear Jeffcott rotor

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Viitala, R. (Risto). "Dynamic radial bearing force measurement of flexible rotor." Master's thesis, University of Oulu, 2018. http://urn.fi/URN:NBN:fi:oulu-201809062733.

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Dynamic characteristics of a paper machine roll have been widely investigated for decades. Vibration of the rolls decrease the paper quality and excites the structures of the paper machine. Therefore, vibration must be avoided and kept at its minimum. Vibration of a rotor develops periodic radial bearing forces, which are connected to the amplitude and the frequency of the vibration. Vibration based forces are unnecessary dynamic forces, which increase the bearing load in addition to unavoidable rotor mass and the external loads of the process. This experimental study presents the amplitudes of the dynamic bearing force caused by a vibrating rotor and enables further measurements and research about the correlation between the radial bearing force and e.g. acceleration data. During the research knowledge about the dynamic behavior of the rotor and developed forces can be increased. The improved knowledge leads to a lower bearing force level, which decreases the oversizing of the structures, enables the design of lighter and more cost-effective structures, extends the lifespan of the machine and improves the quality of the end product. The dynamic radial bearing force amplitudes of a paper machine roll are merely available through simulation models, since physical force sensors are not mounted on the paper machines. Typically, the monitoring of a paper machine is focused on the vibrations of the paper machine rolls, since it is more relevant for to the quality of the paper than the amplitudes of force. Vibration troubleshooting and monitoring tasks have typically been realized through the easy-installed accelerometer measurements. The force measurement of the paper machine roll can produce similar information about the behavior of the rotor and its vibrations as acceleration measurement in addition to the radial force amplitudes. However, utilization of force measurements in vibration monitoring was not found based on a literature survey. The radial bearing force measurement was accomplished by building a test rig and a measurement device for an industrial-size paper machine roll. The radial bearing forces were measured as close as possible to the action point of the load to produce reliable results. The results present the force measurement data, which were acquired with the calibrated and verified measurement device implemented during this study. The measured results revealed the forces affecting on both ends of the test roll. The data was analyzed with Fast Fourier Transform (FFT) to present the forces in the frequency domain and to investigate their harmonic components. The measured forces, which were divided into harmonic components, could be discovered and destabilizing excitations could be defined more efficiently. Based on the present study high harmonic components could be distinguished with the force measurement. The results were compared with two reference measurements, which utilize acceleration and position sensors. The results cannot be generalized, since the measuring results consider only the roll of this research. The roll, the bearings, the bearing support and the foundation form the rotating system, which is always individual. Parameters and excitations affecting to the behavior of the roll are different in every roll. However, the similar behavior can be assumed to be on other flexible rotors as well and those can be measured with similar methods as the present study. In further research additional knowledge about the behavior of the roll and correlations between force, position and acceleration can be achieved for both the scientific and practical engineering purposes with the dynamic bearing force measurement and a simultaneous acceleration or position measurement
Paperikoneen telan värähtelyominaisuuksia on tutkittu laajasti jo vuosikymmeniä. Värähtely heikentää paperin laatua ja aiheuttaa herätettä paperikoneen rakenteisiin. Tästä johtuen värähtely yritetään pitää minimaalisena. Roottorin värähtely aiheuttaa jaksollisia laakerivoimia, jotka ovat yhteydessä värähtelyyn. Värähtelyn aiheuttamat voimat ovat ei-toivottuja dynaamisia voimia, jotka lisäävät laakerivoimia välttämättömän roottorimassan ja muiden prosessista aiheutuvien rasitusten lisäksi. Tämä kokeellinen tutkimus keskittyy värähtelevän roottorin aiheuttamiin dynaamisiin voimiin ja mahdollistaa myöhemmän mittaamisen ja korrelaatioiden tutkimisen laakerivoimien ja esimerkiksi kiihtyvyysmittauksen välillä. Tietoa roottorin dynaamisesta käyttäytymisestä ja syntyvistä voimista voidaan parantaa tällä tutkimuksella. Paperikoneen telan dynaamisten ominaisuuksien parempi tunteminen vähentää rakenteiden ylimitoitusta, mikä mahdollistaa rakenteiden suunnittelun kevyemmäksi ja halvemmaksi, lisää koneen käyttöikää ja parantaa lopputuotteen laatua. Telan värähtelyn aiheuttamia dynaamisia laakerinvoimia on saatavilla vain simuloimalla, mikä tarkoittaa, että fyysisiä voima-antureita ei ole asennettuina paperikoneissa. Yleensä paperikoneen anturointi keskittyy paperikoneen telojen värähtelyyn, sillä se on isompi tekijä paperin laaduntarkkailussa kuin voimamittaus. Värähtelymittaukseen perustuvaa vianetsintää ja prosessivalvontaa on tehty tyypillisesti helposti kiinnitettävillä kiihtyvyysantureilla. Voimamittaus pystyy tuottamaan saman informaation roottorin käyttäytymisestä ja sen värähtelystä kuin kiihtyvyysmittaus laakerivoimien lisäksi. Kuitenkaan, voimamittausta ei käytetä värähtelymittauksiin kirjallisuusselvityksen mukaan. Laakerivoimamittaus suoritetaan rakentamalla koepenkki sekä mittalaite teollisuudessa käytettävälle paperikoneen telalle. Laakerivoimat pyritään mittaamaan mahdollisimman läheltä voimanvaikutuspistettä, että saavutettaisiin mahdollisimman luotettava tulos. Mittatulokset saatiin kalibroidulla ja verifioidulla mittalaitteella, joka oli rakennettu tämän työn aikana. Mittaustulokset paljastivat telan laakereihin syntyvät voimat kummassakin päässä telaa. Tulokset analysoitiin käyttäen nopeaa Fourierin muunnosta (FFT), jotta voimat saatiin taajuustasoon harmonisten komponenttien tutkimiseksi. Mitatut voimat ja niiden amplitudit, jotka olivat esitettyinä harmonisina komponentteina, voitiin löytää ja telan värähtelyä aiheuttavat herätteet voitiin rajata tehokkaammin. Tämän tutkimuksen perusteella voitiin huomata, että korkeat harmoniset taajuudet voitiin havaita voimamittauksella. Tuloksia verrattiin kahteen referenssimittaukseen, jotka oli toteutettu kiihtyvyys- ja paikka-antureilla. Tuloksia ei voitu yleistää, sillä mittaustulokset koskevat vain tämän tutkimuksen telaa. Tela, laakerit, laakerin tuenta ja perusta muodostivat pyörivän systeemin, mikä on aina yksilöllinen. Parametrit ja herätteet, jotka vaikuttavat telan käyttäytymiseen muuttuvat joka telassa. Kuitenkin samanlaista käyttäytymistä voidaan olettaa olevan myös toisissa joustavissa roottoreissa ja ne voidaan mitata samalla tavalla kuin tässä tutkimuksessa. Myöhemmässä tutkimuksessa voidaan saavuttaa lisäarvoa ja korrelaatioita laakerivoiman, siirtymämittauksen ja kiihtyvyysmittauksen välillä tieteellisiin ja käytännön tarkoituksiin dynaamisella laakerivoimamittauksella

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Baseer, M. A. "Control of vibration in a flexible rotor-bearing system." Thesis, University of Bath, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254323.

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Clements, Shaun. "On line vibration of a flexible rotor/bearing system." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302866.

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7

Landry, Céderick. "Dynamique de rotor d’une turbine renversée à moyeu flexible." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10597.

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Le mémoire de maîtrise présente la dynamique de rotor d’une microturbine à gaz à configuration renversée permettant l’intégration de pales en céramique. Cette configuration permet d’utiliser des pales de turbine complètement en céramique car elles sont retenues en compression de l’extérieur par un anneau en composite qui est en rotation. Par contre, la configuration renversée nécessite une nouvelle conception de moyeu de turbine. En effet, l’anneau en composite est loin de l'axe de rotation. Par conséquent, il se dilate beaucoup dus aux efforts centrifuges ce qui entraîne un grand déplacement des pales. L’idée est donc de faire un moyeu flexible qui vient suivre le déplacement des pales pour appliquer une pression en dessous de ceux-ci, afin de les tenir en place par friction. La dynamique de rotor avec moyeu flexible est très peu documentée dans la littérature. Le projet de recherche consiste en la compréhension de la dynamique d’un moyeu flexible pour cibler les paramètres intervenant dans la vibration d’une turbine renversée. La recherche se fera via la conception d’un prototype permettant d’étudier l’effet de la flexibilité pour un concept donné. L’analyse de dynamique de rotor avec moyeu flexible est faite avec un modèle par éléments finis linéaire. Malgré le fait que des non-linéarités peuvent provenir des roulements à billes supportés par des films amortisseurs, un type de roulements couramment utilisé pour supporter des turbocompresseurs, il est démontré qu’un modèle linéarisé capte plutôt bien les tendances mesurées. Le but de ce projet est de déceler les paramètres problématiques d’un moyeu flexible et de découvrir les paramètres permettant une bonne dynamique.

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Lv, Peng. "Performance aérodynamique et structurelle du rotor flexible pour micro-drones." Thesis, Toulouse, ISAE, 2014. http://www.theses.fr/2014ESAE0058/document.

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Les essais en environnement libre et en soufflerie ont été effectués pour étudier la performance propulsive et la déformation de pales de référence et de pales souples. La poussée et le couple ont été évalués par deux méthodes: une mesure directe par balance et une estimation indirecte par bilan de quantité de mouvement, les deux méthodes ayant leurs avantages et limitations respectifs. La méthode indirecte s’est construite sur l’acquisition de champs de vitesse obtenus par PIV et s’appuie sur une estimation de la pression par mise en œuvre de l’équation de Poisson. En vol stationnaire, les pales flexibles ne peuvent pas aider à l’amélioration du rendement en mode rotor (FM), à chargement faible, puisque la distribution de vrillage est sans doute assez éloignée de l’optimal de vol stationnaire. En vol avancé, le rendement propulsif des pales flexibles est la plupart du temps plus élevé que l’hélice rigide de référence en raison de la torsion bénéfique généré en rotation. Dans le cas des pales flexibles, la vitesse axiale se trouve être inférieure au cas rigide, à même station aval; ceci correspondant à la la déformation de vrillage négatif. Pour les deux pales, la différence de poussée entre celle déduite du champ PIV test 2et celle obtenue avec la balance est plus grande que la différence entre les valeurs déduites du champ PIV test 1 et de la mesure directe. La technique de mesure laser pour les déplacements(LDS) a été utilisée pour mesurer la déformation stationnaire des pales lors de leur rotation. Par analyse du nuage de points mesurés par la LDS, la flexion et la torsion de la lame en rotation ont été identifiées à l’aide des régressions multiples
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

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9

Tasaltin, R. "Active vibration control strategies for a flexible rotor-bearing system." Thesis, University of Bath, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303551.

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Perdikologos, Nikolaos Carleton University Dissertation Engineering Mechanical. "Dynamic analysis of flexible disc-rotor systems using component modes." Ottawa, 1985.

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Books on the topic "Flexible rotor"

1

Rieger, N. F. Balancing of rigid and flexible rotors. Washington, DC: Shock and Vibration Information Center, U.S. Dept. of Defense, 1986.

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United States. National Aeronautics and Space Administration., ed. Vibration and control of flexible rotor supported by magnetic bearings. [Washington, DC]: National Aeronautics and Space Administration, 1988.

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E, Zorzi, Mechanical Technology Incorporated, and United States. National Aeronautics and Space Administration., eds. HPOTP low-speed flexible rotor balancing, phase 1: Final report. Latham, New York: Mechanical Technology Incorporated, 1985.

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United States. National Aeronautics and Space Administration., ed. Vibration and control of flexible rotor supported by magnetic bearings. [Washington, DC]: National Aeronautics and Space Administration, 1988.

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HPOTP low-speed flexible rotor balancing, phase 1: Final report. Latham, New York: Mechanical Technology Incorporated, 1985.

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E, Brewe David, Khonsari Michael M, United States. Army Aviation Systems Command., and United States. National Aeronautics and Space Administration., eds. Stability of a rigid rotor supported on flexible oil journal bearings. [Washington, DC]: National Aeronautics and Space Administration, 1987.

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7

Eliseo, DiRusso, Fleming David P, and United States. National Aeronautics and Space Administration., eds. Active vibration control for flexible rotor by optimal direct-output feedback control. [Washington, D.C.]: National Aeronautics and Space Administration, 1989.

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Eliseo, DiRusso, Fleming David P, and United States. National Aeronautics and Space Administration., eds. Active vibration control for flexible rotor by optimal direct-output feedback control. [Washington, D.C.]: National Aeronautics and Space Administration, 1989.

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Eliseo, DiRusso, Fleming David P, and United States. National Aeronautics and Space Administration., eds. Active vibration control for flexible rotor by optimal direct-output feedback control. [Washington, D.C.]: National Aeronautics and Space Administration, 1989.

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10

Viderman, Zvi. On the stability of a dual spin satellite with asymmetric rotor and flexible platform. 1989.

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Book chapters on the topic "Flexible rotor"

1

Rieger, N. F. "Flexible Rotor Balancing." In CISM International Centre for Mechanical Sciences, 95–127. Vienna: Springer Vienna, 1988. http://dx.doi.org/10.1007/978-3-7091-2846-6_5.

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Lesaffre, N., J. J. Sinou, and F. Thouverez. "Stability Analysis of a Flexible Bladed-Rotor." In Damage Assessment of Structures VI, 409–16. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-976-8.409.

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Lusty, Chris, Nicola Y. Bailey, and Patrick S. Keogh. "Control of Flexible Rotor Vibration with Flexibly Mounted Active Magnetic Bearings." In Mechanisms and Machine Science, 65–73. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99270-9_5.

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Kaya, Faris. "Stability of Flexible Rotor Supported on Journal Bearings." In Vibration and Wear in High Speed Rotating Machinery, 559–65. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-1914-3_32.

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Rezaiguia, Abdelouahab, Oussama Zerti, Salah Guenfoud, and Debra F. Laefer. "Dynamic Behavior and Stability of a Flexible Rotor." In Applied Condition Monitoring, 37–50. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-94616-0_4.

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Barzdaitis, Vytautas, Vytautas Žemaitis, R. Jonušas, V. K. Augustaitis, and V. Bučinskas. "Dynamics of a Mechatronic System with Flexible Vertical Rotor." In Solid State Phenomena, 223–28. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/3-908451-21-3.223.

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Dönges, Benjamin, Maximilian Rolfes, and Stefan Buchkremer. "Spring Loaded Rotor Shafts as New Flexible Shaft Hub Joint for E-Rotors." In Proceedings, 56–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-662-61515-7_7.

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Taranenko, Pavel, Oleg Sliva, and Elena Zadorozhnaya. "Dynamics Analysis of Flexible Rotor Supported by Floating Ring Bearings." In Proceedings of the 9th IFToMM International Conference on Rotor Dynamics, 1103–13. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-06590-8_90.

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Knopf, Eric, Thomas Krüger, and Rainer Nordmann. "Residual Unbalance Determination for Flexible Rotors at Operational Speed." In Proceedings of the 9th IFToMM International Conference on Rotor Dynamics, 757–68. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-06590-8_62.

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Nonami, K. "Vibration and Control of Flexible Rotor Supported by Magnetic Bearings." In Magnetic Bearings, 177–86. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-51724-2_18.

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Conference papers on the topic "Flexible rotor"

1

Muszynska, Agnes, Alex Petchenev, and Paul Goldman. "Dynamics of Rotor/Bearing System With Flexible Rotor and Flexible Bearing Support." In ASME 1997 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/detc97/vib-4042.

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Abstract The paper analyzes, theoretically and experimentally, the lowest four lateral modes of an isotropic rotor/fluid-lubricated bearing system with flexible rotor and flexible bearing support. The parameters of the analytical model of the system are identified using sweep-frequency modal testing of the rotor rig. A nonsynchronous, circular-rotating-force excitation was applied sequentially at the rotor and at the fluid-lubricated bearing casing, in order to generate the response data. The approach used in this study emphasizes the dynamic features of the system which are invariant to the choice of coordinate system. The system is described using Dynamic Stiffness matrix. This provides an advantage of simplicity, allowing a comprehensive stability study for various system parameters.

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Vázquez, José A., Lloyd E. Barrett, and Ronald D. Flack. "A Flexible Rotor on Flexible Bearing Supports: Part I — Stability." In ASME 1999 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/detc99/vib-8285.

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Abstract An experimental study of the effects of bearing support flexibility on rotor stability is presented. A flexible roto supported by fluid film bearings on flexible supports was used with fifteen support configurations. The horizontal suppor stiffness was varied systematically while the vertical stiffness was kept constant. The support charactristics were determined experimentally by measuring the frequency response functions of the support structure at the bearing locations. These frequency response functions were used to calculate polynomial transfer functions that represented the support structure. Stability predictions were compared with measured stability thresholds. The predicted stability thresholds agree with the experimental data within a confidence bound for the logarithmic decrement of ±0.01. Predictions for the rotor on rigid supports are included for comparison.

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3

Dikmen, Emre, Peter van der Hoogt, Andre´ de Boer, Ronald Aarts, and Ben Jonker. "A Flexible Rotor on Flexible Supports: Modeling and Experiments." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10851.

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In this study, a flexible rotor with variable support stiffness has been analyzed. Simple support models consisting of mass, spring systems are extracted from modal analysis of the isolated support and by applying static loads to the finite element model of the supports. The derived equivalent models of the supports are then implemented in the finite element based structural model which predicts the dynamic behavior of the rotor. Finally experimental modal analysis of the rotor is performed with different support stiffnesses. The experimental and theoretical results have been compared and different support modeling approaches have been examined.

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Werner, U. "Optimized rotor design for rigid balancing of large flexible induction rotors." In 2011 1st International Electric Drives Production Conference (EDPC). IEEE, 2011. http://dx.doi.org/10.1109/edpc.2011.6085567.

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Arredondo, I., J. Jugo, and V. Etxebarria. "Modelling of a flexible rotor maglev system." In 2006 American Control Conference. IEEE, 2006. http://dx.doi.org/10.1109/acc.2006.1655390.

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Corrêa, Renan F., Edson H. Koroishi, Fabian A. Lara-Molina, and Elenice W. Stiegelmeier. "EIGENVALUE ANALYSIS OF A SIMPLE FLEXIBLE ROTOR." In 6th International Conference on Nonlinear Science and Complexity. São José dos Campos, Brazil: INPE Instituto Nacional de Pesquisas Espaciais, 2016. http://dx.doi.org/10.20906/cps/nsc2016-0018.

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Vázquez, José A., Lloyd E. Barrett, and Ronald D. Flack. "A Flexible Rotor on Flexible Bearing Supports: Part II — Unbalance Response." In ASME 1999 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/detc99/vib-8286.

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Abstract An experimental study of the effects of bearing support flexibility on rotor unbalance response is presented. A flexible rotor supported by fluid film bearings on flexible supports was used with fifteen support configurations. The horizontal support stiffness was varied systematically while the vertical stiffness was kept constant. The support characteristics were determined experimentally by measuring the frequency response functions of the support structure at the bearing locations. These frequency response functions were used to calculate polynomial transfer functions that represented the support structure. The second critical speed of the rotor varied from 3690 rpm to 5200 rpm, depending on the support configuration. The predicted first critical speeds agree with the experimental data within −1.7%. The predicted second critical speeds agree with the experimental data within 3.4%. Predictions for the rotor on rigid supports are included for comparison.

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Brown, R. D., and G. Drummond. "Chaos of a Flexible Rotor in Journal Bearings." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0529.

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Abstract Nonlinear systems can give rise to chaotic behaviour, essentially unpredictable. Oil film forces arising from hydrodynamic bearings in rotating machinery can be extremely nonlinear under conditions of large unbalance. Chaotic response has been demonstrated in theoretical models of rigid rotors supported in hydrodynamic bearings. The behaviour of a rigid rotor can be extended by looking at a flexible rotor model supported on journal bearings and subject to large unbalance levels. The introduction of a flexible shaft yields chaotic regions which are less extensive than those obtained from a rigid rotor model. This is not surprising as the nonlinearity in the model is confined to the oil films at the end of the shaft. However if this level of unbalance is experienced in service then shaft fatigue could occur because of the sustained nature of the non-synchronous response and the effect of the resulting stress reversals.

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Gupta, T. C., and K. Gupta. "Modeling of Flexible Coupling to Connect Misaligned Flexible Rotors Supported on Ball Bearings." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-26891.

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Parallel or/and angular misalignment between rotors connected by flexible coupling causes deformation of coupling elements and rotor shafts both. The forces and moments from flexible coupling act on driver and driven rotors simultaneously and depend upon dynamic response of coupled rotor system. The authors’ aim in the present work is to propose a methodology to incorporate the coupling stiffness matrix and coupling loads into the finite element model of flexibly coupled flexible rotors supported on deep groove ball bearings. The coefficients of coupling stiffness matrix and coupling loads are nonlinear and depend upon the amount of parallel and angular misalignments. To segregate the effect of nonlinear stiffness of coupling on the dynamic response of the system, the stiffness of ball bearing is initially considered to be linear. Thereafter, ball bearing nonlinearities arising from radial clearance, Hertzian deformation of balls and races, and varying compliance effect are included into the FE model of the system. Considering different types of misalignments in succession and combination, the dynamic response is characterized by the presence of 1N, 2N and other super or sub harmonics. The misalignment in one plane is found to affect the dynamic response in both the orthogonal planes. Comparing to the stiffness of flexible coupling, the stiffness of ball bearing is of higher order and therefore, nonlinear coupling forces and moments have dominant influence on the dynamic response of the system.

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Cao, Jianming, Paul Allaire, Timothy Dimond, and Saeid Dousti. "Auxiliary Bearing System Optimization for AMB Supported Rotors Based on Rotor Drop Analysis: Part I — Rotor Drop Analysis Method." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56323.

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For rotors supported with active magnetic bearings (AMBs), the auxiliary bearing system or backup bearing system is needed to avoid serious potential internal damaging in the event of AMB loss of power or overload. The evolution of auxiliary systems has been made a priority by the American Petroleum Institute using analytical or experimental methods. In part I of this paper, a detailed rotor drop nonlinear transient analysis method including flexible shaft, rolling element bearing components including inner/outer races and balls, as well as flexible/damped supporting structures is given. A finite element based 6-DOF flexible rotor model is used to indicate shaft motion before the drop (operating conditions) and during the rotor drop event. Un-lubricated Hertzian contact models are used between the shaft and inner/outer races, between balls and races. To avoid heavy calculating time, two different methods to calculate ball bearing contact loads are discussed and the simulation results are compared. These models are applied to predict shaft-race-ball displacements and angular speeds, contact loads and ball bearing stresses during the drop for angular contact auxiliary bearings. This method also can be used to design and optimize the auxiliary bearing system as presented in the 2nd part of this paper.

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