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Статті в журналах з теми "Multi-Stage Bladed Disks Dynamics"
1
Bladh, R., M. P. Castanier, and C. Pierre. "Effects of Multistage Coupling and Disk Flexibility on Mistuned Bladed Disk Dynamics." Journal of Engineering for Gas Turbines and Power 125, no. 1 (December 27, 2002): 121–30. http://dx.doi.org/10.1115/1.1498267.
Повний текст джерелаАнотація:
The effects of disk flexibility and multistage coupling on the dynamics of bladed disks with and without blade mistuning are investigated. Both free and forced responses are examined using finite element representations of example single and two-stage rotor models. The reported work demonstrates the importance of proper treatment of interstage (stage-to-stage) boundaries in order to yield adequate capture of disk-blade modal interaction in eigenfrequency veering regions. The modified disk-blade modal interactions resulting from interstage-coupling-induced changes in disk flexibility are found to have a significant impact on (a) tuned responses due to excitations passing through eigenfrequency veering regions, and (b) a design’s sensitivity to blade mistuning. Hence, the findings in this paper suggest that multistage analyses may be required when excitations are expected to fall in or near eigenfrequency veering regions or when the sensitivity to blade mistuning is to be accounted for. Conversely, the observed sensitivity to disk flexibility also indicates that the severity of unfavorable structural interblade coupling may be reduced significantly by redesigning the disk(s) and stage-to-stage connectivity. The relatively drastic effects of such modifications illustrated in this work indicate that the design modifications required to alleviate veering-related response problems may be less comprehensive than what might have been expected.
2
Wagner, L. F., and J. H. Griffin. "Blade Vibration With Nonlinear Tip Constraint: Model Development." Journal of Turbomachinery 112, no. 4 (October 1, 1990): 778–85. http://dx.doi.org/10.1115/1.2927721.
Повний текст джерелаАнотація:
Turbine blades having integrally machined tip shrouds, with associated gaps between adjacent shrouds, often exhibit unusual vibratory responses with significant differences between the amplitudes and frequencies of individual blades on the same stage. These differences result from unavoidable variations in the shroud gaps causing, for large enough excitation, nonlinear constraint at the blade tips which varies from blade to blade. This study shows that the blade stresses cannot be adequately represented by the type of single-degree-of-freedom models that are often used for dynamic impact studies, but require the participation of higher frequency beam-type modes. The extension of the resulting beam model to multi-degree-of-freedom systems will allow the study of the “gap mistuning” phenomenon for practical bladed disks.
3
Laxalde, Denis, Jean-Pierre Lombard, and Fabrice Thouverez. "Dynamics of Multistage Bladed Disks Systems." Journal of Engineering for Gas Turbines and Power 129, no. 4 (April 27, 2007): 1058–64. http://dx.doi.org/10.1115/1.2747641.
Повний текст джерелаАнотація:
This paper presents a new and original method for dynamical analysis of multistage cyclic structures such as turbomachinery compressors or turbines. Each stage is modeled cyclically by its elementary sector and the interstage coupling is achieved through a cyclic recombination of the interface degrees of freedom. This method is quite simple to set up; it allows us to handle the finite element models of each stage’s sector directly and, as in classical cyclic symmetry analysis, to study the nodal diameter problems separately. The method is first validated on a simple case study which shows good agreements with a complete 360 deg reference calculation. An industrial example involving two HP compressor stages is then presented. Then the forced response application is presented in which synchronous engine order type excitations are considered.
4
Filsinger, D., J. Szwedowicz, and O. Scha¨fer. "Approach to Unidirectional Coupled CFD–FEM Analysis of Axial Turbocharger Turbine Blades." Journal of Turbomachinery 124, no. 1 (February 1, 2001): 125–31. http://dx.doi.org/10.1115/1.1415035.
Повний текст джерелаАнотація:
This paper describes an approach to unidirectional coupled CFD–FEM analysis developed at ABB Turbo Systems Ltd. Results of numerical investigations concerning the vibration behavior of an axial turbocharger turbine are presented. To predict the excitation forces acting on the rotating blades, the time-resolved two-dimensional coupled stator–rotor flow field of the turbine stage was calculated. The unsteady pressure, imposed on the airfoil contour, leads to circumferentially nonuniform and pulsating excitation forces acting on the rotating bladed disk. A harmonic transformation of the excitation forces into the rotating coordinate system of a single blade was elaborated and the complex Fourier amplitudes were determined. The bladed rotor was modeled by a single symmetric segment with complex circumferential boundary conditions. With respect to different nodal diameter numbers, free vibration analyses of the disk assembly were then effectively performed. For calculated resonance conditions, the steady-state responses of the turbocharger bladed disk were computed. By using this coupled CFD–FEM analysis, the dynamic loading of the turbine blades can be determined in the design process.
5
Pešek, Ludĕk, Ladislav Půst, Vítĕzslav Bula, and Jan Cibulka. "Application of Piezofilms for Excitation and Active Damping of Blade Flexural Vibration." Archives of Acoustics 40, no. 1 (March 1, 2015): 59–69. http://dx.doi.org/10.1515/aoa-2015-0008.
Повний текст джерелаАнотація:
Abstract The steam turbine blades of low pressure stages are endangerd by the high-cyclic fatigue due to the combined loading of dynamic stresses by the steam time-variant pressure and the pre-stress from centrifugal forces. Therefore, the importance of their experimental dynamic analysis in the design stage is critical. For laboratory tests of the blades, the piezo actuators placed on the blades, unlike electromagnets placed in the stationary space, give a possibility to excite the flexural vibration of the blades within the bladed disk by time continuous forces independently of the rotor revolutions. In addition, the piezo actuators can be also used to control the vibrations of the blade. Therefore, several dynamic experiments of the clamped model blade equipped with PVDF films were performed for the force description of the piezo foils and their behavior as actuators of the blade vibration. The numerical beam models were used for numerical analysis of the vibration suppression effects both by additional parametric excitation and by active damping. The optimal phase shift of piezo actuator voltage supply was ascertained both for amplitude amplification and suppression. The results contribute to the knowledge of the actuation and active damping of blade vibration by the piezo elements
6
Laxalde, Denis, and Christophe Pierre. "Modelling and analysis of multi-stage systems of mistuned bladed disks." Computers & Structures 89, no. 3-4 (February 2011): 316–24. http://dx.doi.org/10.1016/j.compstruc.2010.10.020.
Повний текст джерела
7
Repetckii, Oleg, and Van Vinh Nguyen. "DYNAMIC CHARACTERISTICS ANALYSIS OF BLADED DISK TURBOMACHINES BASED ON INTENTIONAL MISTUNING." Perm National Research Polytechnic University Aerospace Engineering Bulletin, no. 62 (2020): 61–70. http://dx.doi.org/10.15593/2224-9982/2020.62.07.
Повний текст джерелаАнотація:
To increase technical level of energy turbomachine in modern turbomachinery, high reliability and durability of structures are required in the design, manufacture and operation of turbomachine. Any change geometry, mass, material properties of the bladed disk of turbomachine in the design is called mistuning parameters. With a small value of mistuning blades can significantly increase amplitude, displacement or stresses of the blades structures. So, analysis influence of the effect mistuning parameters on the dynamic characteristics in the field of turbomachine is an important and urgent task. This article analyzes the effect intentional mistuning of the axial bladed disk turbomachine in order to reduce forced response due to low-order engine excitation. The maximum value forced response of rotor blades turbomachine with mistuning parameters is usually much more than that of the tuned rotors. An increase level mistuning of this critical value actually leads to a decrease magnifications of the forced response. Thus, the actual work has been introducing some degree of intentional mistuning in the design to achieve these purposes. In this paper, we study the effectiveness of intentional mistuning at the design stage bladed disk turbomachine, which is introduced into the rotor design by changing the nominal mass of the blades in harmonic Формаls.
8
Sun, Hongyun, and Huiqun Yuan. "Mistuning parameter identification and vibration localization analysis of the integration rotor." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 236, no. 2 (November 14, 2021): 238–53. http://dx.doi.org/10.1177/0954410020981465.
Повний текст джерелаАнотація:
This paper deals with the coupling vibration characteristic of the disk-blade-shaft integration rotor. First, a reduced-order model (ROM) based on an improved hybrid interface component mode synthesis method (IHISCMSM) is carried out, which takes the prestress effect into account. The frequency of the disk-blade-shaft integration rotor at different rotating speeds are calculated and the influence of selecting different mode truncation numbers is investigated. In order to quantitatively evaluate the coupling degree of blade and disk, the coupling factor is defined from the perspective of strain energy, and the influence of prestress on system’s dynamic is discussed. Then, an experimental modal analysis is performed on blades to identify the mistuning parameters, and the mode localization of the disk-blade-shaft integration rotor is analyzed with and without blade mistuning. The results indicate that there are several types of coupling modes among blade, disk and shaft of the integration rotor. After considering the prestress, the frequency increases, and the axial coupling vibration degree and radial coupling vibration degree of the integration rotor change. The mode localization of mistuned rotor is more likely to occur in the modes dominated by mistuning stage blades. There also exists a subtle mode localization phenomenon for tuned integration rotor.
9
Shengxi, Jia, Zheng Longxi, Jingjing Huang, and Qing Mei. "Dynamic Characteristics Analysis and Optimization Design of a Simulated Power Turbine Rotor Based on Finite Element Method." International Journal of Turbo & Jet-Engines 37, no. 1 (March 26, 2020): 31–39. http://dx.doi.org/10.1515/tjj-2017-0006.
Повний текст джерелаАнотація:
AbstractThe vibration optimum design for a simulated power turbine rotor without blades on the disk by using an optimization method based on the finite element method is described in this paper. The installation position of the two-stage turbine disks is chosen as design variables under the constraints of feasible regions for the critical speeds of the rotor. The objective functions are to minimize the transient response of the acceleration at the bearings and the amplitude of the disks. Predictions of the dynamic characteristics of the rotor are obtained by using ANSYS code. The optimization problem is solved by using commercial optimization code ISIGHT. The optimum installation position of the two-stage turbine disks is determined after optimization design. Experimental tests under the optimized structure show that the amplitude of the two-stage turbine disks which are recognized as the most concerned optimization objectives are reduced by 59 % and 56 % respectively in comparison with the comparative structure. The encouraging results demonstrate the potential of the presented method as an engineering design tool and also lay a foundation for the design of the real power turbine rotor used in turbo-shaft engine.
10
Kablitz, Stephan, Jörg Bergner, Dietmar K. Hennecke, Manfred Beversdorff, and Richard Schodl. "Darmstadt Rotor No. 2, III: Experimental Analysis of an Aft-Swept Axial Transonic Compressor Stage." International Journal of Rotating Machinery 9, no. 6 (2003): 393–402. http://dx.doi.org/10.1155/s1023621x0300037x.
Повний текст джерелаАнотація:
At Darmstadt University of Technology (Darmstadt, Germany), the Department of Gas Turbines and Flight Propulsion operates a single-stage transonic compressor test stand. Its main purpose is to provide a database for the validation of computational fluid dynamics codes. In addition, it serves as a testbed for new materials and also for the development of new measurement techniques. After setting up the test rig with a baseline rotor (Rotor No. 1), a titanium bladed disk with conventional radially stacked blade sections, a new rotor (Rotor No. 2) was designed, with the addition of considerable amounts of aft sweep and backward lean. The new rotor's flow field and mechanical properties were investigated by using various measurement techniques, including a laser-2-focus setup.
Дисертації з теми "Multi-Stage Bladed Disks Dynamics"
1
Sternchüss, Arnaud. "Multi-level parametric reduced models of rotating bladed disk assemblies." Phd thesis, Ecole Centrale Paris, 2009. http://tel.archives-ouvertes.fr/tel-00366252.
Повний текст джерелаАнотація:
Les disques aubagés, que l'on trouve dans les turbomachines, sont des structures complexes dont le comportement vibratoire est généralement déterminé par l'exploitation de conditions de symétrie dans leur configuration nominale. Cette symétrie disparaît lorsque l'on assemble plusieurs de ces disques pour former un rotor ou que l'on introduit une variabilité spatiale des paramètres mécaniques (on parle de désaccordage intentionnel ou non). Le raffinement des maillages, nécessaire à une évaluation correcte de la répartition des contraintes, conduirait à des modèles de rotor complet de taille prohibitive (plusieurs dizaines de millions de degrés de liberté). L'objectif de cette thèse est donc l'introduction de méthodologies de réduction qui par combinaison de calculs acceptables permettent d'étudier de façon fine la dynamique d'ensemble sur des modèles 3D fins multi-étages et potentiellement désaccordés. L'étude des transformations de Fourier séparées des réponses de chaque étage permet, dans un premier temps, de bien comprendre les effets de couplage inter-harmonique liés au couplage inter-disque et au désaccordage. A partir de ce constat, une première méthode utilise les résultats de calculs en symétrie cyclique et à secteur encastré pour construire un modèle de secteur exact pour certains modes dits cibles et de très bonne qualité pour les autres modes. Cette méthode est ensuite étendue au cas multi-étage en construisant des bases de réduction de secteur par combinaison de solutions mono-harmoniques. Les illustrations montrent que la méthodologie proposée permet le traitement de modèles de très grande taille, tout en restant compatible avec une grande richesse de post-traitements (calculs de modes, calculs de réponses forcées, analyses de leur contenu harmonique spatial, répartition d'énergie et effets de localisation...). La méthodologie est enfin étendue à la gestion de modèles paramétrés en vitesse de rotation. L'enrichissement des ensembles de modes cibles par des calculs à trois vitesses permet ainsi une reconstruction rapide de l'évolution des fréquences pour l'ensemble d'un intervalle.
2
Segui, Vasquez Bartolomé. "Modélisation dynamique des systèmes disque aubes multi-étages : Effets des incertitudes." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00961270.
Повний текст джерелаАнотація:
Les conceptions récentes de turbomachines ont tendance à évoluer vers des liaisons entre étages de plus en plus souples et des niveaux d'amortissement faibles, donnant lieu à des configurations où les modes sont susceptibles de présenter des niveaux de couplages inter-étages forts. En général, les ensembles disques aubes multi-étagés n'ont aucune propriété de symétrie cyclique d'ensemble et l'analyse doit porter sur un modèle de la structure complète donnant lieu à des calculs très coûteux. Pour palier ce problème, une méthode récente appelée symétrie cyclique multi-étages peut être utilisée pour réduire le coût des calculs des rotors composés de plusieurs étages, même lorsque les étages ont un nombre différent de secteurs. Cette approche profite de la symétrie cyclique inhérente à chaque étage et utilise une hypothèse spécifique qui aboutit à des sous-problèmes découplés pour chaque ordre de Fourier spatial. La méthodologie proposée vise à étudier l'effet des incertitudes sur le comportement dynamique des rotors en utilisant l'approche de symétrie cyclique multi-étages et l'expansion en Chaos Polynomial. Les incertitudes peuvent découler de l'usure des aubes, des changements de température ou des tolérances de fabrication. En première approche, seules les incertitudes provenant de l'usure uniforme de l'ensemble des aubes sont étudiées. Celles-ci peuvent être modélisées en considérant une variation globale des propriétés du matériau de l'ensemble des aubes d'un étage particulier. L'approche de symétrie cyclique multi-étages peut alors être utilisée car l'hypothèse de secteurs identiques est respectée. La positivité des matrices aléatoires concernées est assurée par l'utilisation d'une loi gamma très adaptée à la physique du problème impliquant le choix des polynômes de Laguerre comme base pour le chaos polynomial. Dans un premier temps des exemples numériques représentatifs de différents types de turbomachines sont introduits dans le but d'évaluer la robustesse de la méthode de symétrie cyclique multi-étages. Ensuite, les résultats de l'analyse modale aléatoire et de la réponse aléatoire obtenus par le chaos polynomial sont validés par comparaison avec des simulations de Monte-Carlo. En plus des résultats classiquement rencontrés pour les fréquences et réponses forcées, les incertitudes considérées mettent en évidence des variations sur les déformées modales qui évoluent entre différentes familles de modes dans les zones de forte densité modale. Ces variations entraînent des modifications sensibles sur la dynamique globale de la structure analysée et doivent être considérées dans le cadre des conceptions robustes.
3
Salles, Loïc. "Etude de l'usure par fretting sous chargements dynamiques dans les interfaces frottantes : application aux pieds d'aubes de turbomachines." Phd thesis, Ecole Centrale de Lyon, 2010. http://tel.archives-ouvertes.fr/tel-00600613.
Повний текст джерелаАнотація:
Les parties tournantes des turbomachines aéronautiques sont composées d'une succession de roues aubagées qui permettent le transfert de l'énergie entre l'air et le rotor. Ces roues aubagées constituent des pièces particulièrement sensibles car elles doivent répondre en termes de dimensionnement à des impératifs de performances aérodynamiques, d'aéroacoustique et de tenue mécanique à la rotation,à la température et à la charge aérodynamique. Le contact avec frottement existant au niveau des attaches aube-disque joue un rôle important sur les niveaux vibratoires.Ce travail porte sur l'étude de l'usure par fretting sous chargements dynamiques dans les interfaces frottantes. En effet, les vibrations de l'aube peuvent produire des micro-glissements en pied d'aubequi peuvent entraîner un phénomène d'usure par fretting. Les connaissances sur le comportement de l'usure sous sollicitations dynamiques sont faibles. Seuls existent des outils numériques pour modéliser l'usure dans le cas de sollicitations quasi-statiques. Nous proposons dans cette thèse des méthodes pour calculer l'évolution de l'usure au cours des cycles de chargement dynamique basées sur une approche multi-échelle en temps. La réponse vibratoire de la structure est liée à une échelle de temps rapide qui est calculée par une méthode d'équilibrage harmonique, dans laquelle les déplacements et les efforts sont projetés sur la base de Fourier. Différentes approches temps-fréquence de calcul des coefficients de Fourier des forces de contact sont présentées. La cinétique d'usure est liée à une échelle lente et différentes méthodes sont proposées pour l'intégrer. La prise en compte des géométries usées dans le modèle éléments finis se fait par l'ajout d'un vecteur des profondeurs d'usure dans le terme de pénalité des lagrangiens dynamiques. Des exemples académiques valident et illustrent les méthodes proposées. Ces méthodes sont ensuite appliquées à l'étude de l'usure par fretting en pied d'aube de soufflante. L'étude numérique met en lumière le couplage entre vibration et usure par fretting aux interfaces de contact. La modification du comportement dynamique global de la roue aubagée est aussi observée.
Тези доповідей конференцій з теми "Multi-Stage Bladed Disks Dynamics"
1
Laxalde, Denis, Jean-Pierre Lombard, and Fabrice Thouverez. "Dynamics of Multi-Stage Bladed Disks Systems." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27083.
Повний текст джерелаАнотація:
This paper presents a new and original method for dynamical analysis of multi-stage cyclic structures such as turbomachinery compressors or turbines. Each stage is modeled cyclically by its elementary sector and the inter-stage coupling is achieved through a cyclic recombination of the interface degrees of freedom. This method is quite simple to set-up; it allows to handle the finite element models of each stage’s sector directly and, as in classical cyclic symmetry analysis, to study the nodal diameter problems separately. The method is first validated on a simple case study which shows good agreements with a complete 360° reference calculation. An industrial example involving two HP compressor stages is then presented. Then the forced response application is presented in which synchronous of engine order type excitations are considered.
2
Bladh, Ronnie, Matthew P. Castanier, and Christophe Pierre. "Effects of Multi-Stage Coupling and Disk Flexibility on Mistuned Bladed Disk Dynamics." In ASME Turbo Expo 2001: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/2001-gt-0277.
Повний текст джерелаАнотація:
The effects of disk flexibility and multi-stage coupling on the dynamics of bladed disks with and without blade mistuning are investigated. Both free and forced responses are examined using finite element representations of example single- and two-stage rotor models. The reported work demonstrates the importance of proper treatment of interstage (stage-to-stage) boundaries in order to yield adequate capture of disk-blade modal interaction in eigenfrequency veering regions. The modified disk-blade modal interactions resulting from interstage-coupling-induced changes in disk flexibility are found to have a significant impact on (a) tuned responses due to excitations passing through eigenfrequency veering regions, and (b) a design’s sensitivity to blade mistuning. Hence, the findings in this paper suggest that multi-stage analyses may be required when excitations are expected to fall in or near eigenfrequency veering regions or when the sensitivity to blade mistuning is to be accounted for. Conversely, the observed sensitivity to disk flexibility also indicates that the severity of unfavorable structural interblade coupling may be reduced significantly by re-designing the disk(s) and stage-to-stage connectivity. The relatively drastic effects of such modifications illustrated in this work indicate that the design modifications required to alleviate veering-related response problems may be less comprehensive than what might have been expected.
3
Laxalde, Denis, and Fabrice Thouverez. "Non-Linear Vibrations of Multi-Stage Bladed Disks Systems With Friction Ring Dampers." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34473.
Повний текст джерелаАнотація:
In this paper, we study the non-linear dynamics of a multi-stage system of turbomachinery bladed disks with friction dampers. We focus on the quasi-periodic forced response of this system under multi-frequency rotating excitations. The system’s equations of the motion are expressed in the multi-frequency domain using a multi-frequency harmonic balance method in combination a multi-stage cyclic symmetry reduction. A Dynamic Lagrangian formulation in alternating frequency/time domains is also used for the calculation of the contact and friction forces. In applications we consider a system of two HP compressor stages of integrally bladed disks with friction ring dampers.
4
D'Souza, Kiran, Akira Saito, and Bogdan Epureanu. "Reduced Order Modeling for Nonlinear Vibration Analysis of Mistuned Multi-Stage Bladed Disks with a Cracked Blade." In 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2011. http://dx.doi.org/10.2514/6.2011-2065.
Повний текст джерела
5
Boulton, Luis A., and Euro Casanova. "Reduced Order Model for a Two Stage Gas Turbine Including Mistuned Bladed Disks and Shaft Interaction." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59335.
Повний текст джерелаАнотація:
A number of previous works have suggested that in some cases the interaction between shaft and bladed disk modes could significantly modify the dynamics of the whole assembly i.e. the bladed disks mounted on a flexible shaft. This paper presents the application of a previously published reduced-order modeling technique to the dynamical modeling of a real two stage gas turbine, including the bladed disks and the shaft. In the resulting reduce order model, mistuning is included in the bladed disk models and the shaft is modeled using beam finite elements according to the classical rotordynamic approach. Generation of finite element parent model for the real turbine is presented and discussed as well as simplifications used in order to generate the reduced order model. Comparisons are made between the reduced model and the full finite element solution for free response frequencies and mode shapes in order to assess the methodology and to evaluate the impact of simplifying hypothesis considered in model generation. Finally, this work also shows interaction between shaft modes and bladed disk modes, therefore confirming that stage independent analysis might not be adequate for predicting the global dynamic response of some turbomachinery rotors.
6
Rzadkowski, Romuald, and Artur Maurin. "Multi-Stage Coupled Forced Response of Aircraft Engine Compressor and Turbine Bladed Discs." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57643.
Повний текст джерелаАнотація:
Considered here is the effect of multistage coupling on the dynamics of an aircraft engine rotor with eight mistuned bladed discs on a drum-disc shaft during foreign object ingestion (FOI). In the dynamic model, each disc had a different number of rotor blades. Free and forced vibrations were examined using finite element models of single rotating blades, bladed discs and an entire rotor with bladed discs. Calculations of the mode shapes of flexible mistuned bladed disc-shaft assemblies took into account simultaneous excitations of the first and second stages of the compressor and the turbine bladed disc with 0EO, 1EO and 2EO. The thus obtained maximal stress values of all of the rotor blades were carefully examined and compared with a tuned system to discover resonance conditions and coupling effects. Our investigation has shown that mistuning changes the stress distribution in individual rotor blades and the level of maximum stress increases in relation to single or multiple bladed disc excitation.
7
Yu, Hongbiao, and K. W. Wang. "Vibration Suppression of Mistuned Coupled-Blade-Disk Systems Using Piezoelectric Circuitry Network." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34443.
Повний текст джерелаАнотація:
In this research, piezoelectric networking is investigated as an effective means for vibration suppression of mistuned bladed disk systems. Due to mistuning (i.e., imperfections in blade properties), bladed disks in turbo-machinery often suffer from vibration localization. In such cases, the vibration energy is confined to a small number of blades and forced response can be drastically increased when the structure is under engine order force excitation. To suppress the excessive vibration caused by localization, a piezoelectric networking concept has been proposed and analyzed for a multi-blade system in a previous study by the authors [1]. This research further extends the investigation with focus on circuitry design for a complex bladed disk model with the consideration of coupled blade-disk dynamics. A new multi-circuit piezoelectric network is designed and analyzed for multiple-harmonic vibration suppression of bladed disks. An optimal network is derived analytically based on system analysis. The performance of the network for bladed disks with random mistuning is examined using Monte Carlo simulation. The effects of variations (mistuning and detuning) in circuit parameters are also studied. Finally, a method to improve system performance and robustness is discussed.
8
Srinivas, Siva, Hardik Roy, and Esakki Muthu Shanmugam. "Study of the Effect of Multi-Stage Cyclic Symmetric Modeling on the Natural Frequencies of Bladed Disks of an Aero Engine Rotor System." In ASME 2015 Gas Turbine India Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gtindia2015-1297.
Повний текст джерелаАнотація:
Majority of the failures in Gas turbine Blades are caused by High Cycle Fatigue induced by the vibratory stresses in the rotor blades. The first step in blade design is the prevention of coincidence of natural frequencies of the blades with the frequencies of the fluctuating Gas loads. The forcing frequency is a function of number of upstream and downstream stator blades, and rotational speed. In gas turbines with multiple stages, modal analysis of bladed-disks is individually performed i.e. stage by stage. As the structure is rotationally periodic, cyclic symmetric boundary conditions can be utilized, over 360 degree modeling. The advantage of cyclic symmetry over full model lies in reduced degrees of freedom and hence reduced computational time. In most of the available tools, cyclic symmetry for modal analysis is limited to single stage. As such there is no provision to model and analyze multiple stages at the same time. This leads to inaccurate values of natural frequencies as the flexibility introduced by the adjacent stages is not being taken into consideration. An alternative to this is full 3D modeling and analysis of all the combined stages. Bladh et al. (2003) [1] have shown that interstage coupling can significantly affect the dynamics of the multi-stage assembly and in some cases lead to an underestimation of vibratory levels. Sokolowski et al [2] studied the influence of inclusion of shaft in the model on the natural frequencies and mode shapes of the shrouded bladed discs up to four nodal diameters for first two frequency series (mode shapes). Rzadkowski and Drewczynski (2006) [3] have used full 360 degrees models to study the free and forced dynamics of multi-stage systems. However this method is avoided as the computational cost is prohibitive. Multi stage cyclic symmetry overcomes this obstacle in which each stage is cyclically modeled and an inter-stage coupling is introduced between adjacent stages. The advantage of multi stage cyclic symmetry lies in the significant reduction in the number of elements and therefore computational time. Laxalde et al. (2007) [4] were the first to come up with the method of dynamic analysis of turbo machinery rotors with multi stage cyclic symmetry using interstage coupling. They considered an example of two-stage High Pressure compressor. The results were validated against a complete 360 degrees reference model. Forced response analysis of rotor stages to fluctuating gas loads with and without interstage coupling definition was also presented and compared. In the present work a complete Gas Turbine rotor system with multiple stages of Compressor, Shaft and Turbine were analyzed together.
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Firrone, Christian M., Giuseppe Battiato, and Bogdan I. Epureanu. "Modelling the Microslip in the Flange Joint and its Effect on the Dynamics of a Multi-Stage Bladed Disk Assembly." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57998.
Повний текст джерелаАнотація:
The complex architecture of aircraft engines requires demanding computational efforts to take into account the dynamic coupling of the many components constituting the whole assembly. For this reason numerically efficient Reduced Order Models (ROM) and techniques have been developed with the aim of reproducing the global dynamics of the system being computationally fast at the same time. In particular, ROMs have been presented to perform the modal analysis and the calculation of the forced response of rotating components like turbine bladed disks multi-stage assembly. In order to study the effect that joints may have in terms of nonlinearities due to friction in complex structures, in this paper the flange joint is studied as a source of damping due to microslip occurring at the contact interface between two turbine disks. An analytical contact model is proposed to calculate the local microslip based on the different deformations that the two flanges take during vibration. The model is first introduced using a simple geometry representing two flanges in contact and then it is applied to a reduced FE model in order to calculate the nonlinear forced response.
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Corral, Roque, and Juan Manuel Gallardo. "Non-Linear Dynamics of Multi-Mode Unstable Bladed-Disks: Part I—Description of a Canonical Model and Phenomenological Results." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45983.
Повний текст джерелаАнотація:
A simple model that describes the non-linear dynamics of bladed-disk due to the dry friction exerted in attachment and the unsteady aerodynamic forced induced by the vibration of aerodynamically unstable airfoils is presented and analyzed. The analysis is focused on a simplified case whose dynamics is representative of a high aspect ratio low-pressure turbine rotor-blade. A parametric study is conducted to understand the dynamics of the the problem for times much longer than the fundamental period of the rotor blades, when the effect of the initial conditions is not relevant and a periodic steady state has been reached. It is concluded that the conjecture that the dynamics of multi-mode unstable bladed-disk, in the absence of external periodic forcing, finally reaches a state in which only a single traveling-wave exists is true and that this behavior may be reproduced using simplified models.