Control of Rotor-Blade Coupled Vibrations Using Shaft-Based Actuation

René Hardam Christensen; Ilmar Ferreira Santos

doi:10.1155/2006/398658

Control of Rotor-Blade Coupled Vibrations Using Shaft-Based Actuation

Shock and Vibration ◽

10.1155/2006/398658 ◽

2006 ◽

Vol 13 (4-5) ◽

pp. 255-271 ◽

Cited By ~ 1

Author(s):

René Hardam Christensen ◽

Ilmar Ferreira Santos

Keyword(s):

Active Control ◽

Mode Shape ◽

Rotor Blade ◽

Experimental Control ◽

Dynamical Characteristics ◽

Blade Vibrations ◽

Blade System ◽

Bladed Rotor ◽

Controllability And Observability ◽

Interaction Phenomena

When implementing active control into bladed rotating machines aiming at reducing blade vibrations, it can be shown that blade as well as rotor vibrations can in fact be controlled by the use of only shaft-based actuation. Thus the blades have to be deliberately mistuned. This paper investigates the dynamical characteristics of a mistuned bladed rotor and shows how, why and when a bladed rotor becomes controllable and observable if properly mistuned. As part of such investigation modal controllability and observability of a tuned as well as a mistuned coupled rotor-blade system are analysed. The dependency of the controllability and observability on varying rotational speed and mode shape interaction phenomena between parametric and basis mode shape components are also analysed. Numerical results reveal a limitation of the achievable controllability and observability, once quantitative measures of modal controllability and observability converge toward steady levels as the degree of mistuning is increased. Finally, experimental control results are presented to prove the theoretical conclusions and to show the feasibility of controlling rotor and blade vibrations by means of shaft-based actuation in practice.

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Active Rotor-Blade Vibration Control Using Shaft-Based Electromagnetic Actuation

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2056533 ◽

2004 ◽

Vol 128 (3) ◽

pp. 644-652 ◽

Cited By ~ 7

Author(s):

René H. Christensen ◽

Ilmar F. Santos

Keyword(s):

Rotor Blade ◽

Experimental Tests ◽

Centralized Control ◽

Blade Vibration ◽

Electromagnetic Actuators ◽

Blade System ◽

Bladed Rotor ◽

Displacement Transducers ◽

System Configurations ◽

Controllability And Observability

In this paper the feasibility of actively suppressing rotor and blade vibration via shaft-based actuation is studied. A mathematical model is derived, taking into account the special dynamical characteristics of coupled rotor-blade systems, such as centrifugal stiffened blades and parametric vibration modes. An investigation of controllability and observability shows that if the blades are properly mistuned, it is possible to suppress shaft as well as blade vibration levels by using only shaft-based actuation and sensing; though, in tuned bladed systems, shaft as well as blade actuation and sensing are required. In order to cope with the time-variant dynamics of the coupled rotor-blade system, a periodic time-variant modal controller is designed, implemented, and experimentally tested. A test rig built by four flexible blades is specially designed for this purpose. The rig is equipped with six electromagnetic actuators and different types of sensors (eddy-current displacement transducers, acceleration transducers, and strain gages) with the aim of monitoring and controlling shaft and blade vibration levels. Two different actively controlled rotor-blade system configurations are considered in the present study: (i) a tuned bladed rotor, controlled with help of actuators attached to the rotating blades and shaft-based actuators; (ii) a deliberately mistuned bladed rotor controlled only via shaft-based actuation. Experimental tests are carried out for both configurations. Some experimental problems regarding control implementation are identified and discussed, especially when the controller order and the number of actuators in the centralized control scheme become too high; though, for the mistuned bladed rotor controlled by using only shaft-based actuation, the controller works well.

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An improved dynamic load-strength interference model for the reliability analysis of aero-engine rotor blade system

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410020972898 ◽

2020 ◽

pp. 095441002097289

Author(s):

Bingfeng Zhao ◽

Liyang Xie ◽

Yu Zhang ◽

Jungang Ren ◽

Xin Bai ◽

...

Keyword(s):

Reliability Analysis ◽

Dynamic Load ◽

Rotor Blade ◽

Engineering Application ◽

Weight Ratio ◽

System Component ◽

Aero Engine ◽

Blade System ◽

Improved Model ◽

Engine Rotor

As the power source of an aircraft, aero-engine tends to meet many rigorous requirements for high thrust-weight ratio and reliability with the continuous improvement of aero-engine performance. In this paper, based on the order statistics and stochastic process theory, an improved dynamic load-strength interference (LSI) model was proposed for the reliability analysis of aero-engine rotor blade system, with strength degradation and catastrophic failure involved. In presented model, the “unconventional active” characteristic of rotor blade system, changeable functioning relationships and system-component configurations, was fully considered, which is necessary for both theoretical analysis and engineering application. In addition, to reduce the computation cost, a simplified form of the improved LSI model was also built for convenience of engineering application. To verify the effectiveness of the improved model, reliability of turbojet 7 engine rotor blade system was calculated by the improved LSI model based on the results of static finite element analysis. Compared with the traditional LSI model, the result showed that there were significant differences between the calculation results of the two models, in which the improved model was more appropriate to the practical condition.

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Modeling of a Wind Turbine Rotor Blade System

Journal of Vibration and Acoustics ◽

10.1115/1.4036633 ◽

2017 ◽

Vol 139 (5) ◽

Cited By ~ 6

Author(s):

Dayuan Ju ◽

Qiao Sun

Keyword(s):

Wind Turbine ◽

Rotor Blade ◽

Simulation Software ◽

Wind Flow ◽

Coupling Effects ◽

Horizontal Axis Wind Turbine ◽

Blade Vibration ◽

Proposed Model ◽

Blade System ◽

Coupling Terms

In wind turbine blade modeling, the coupling between rotor rotational motion and blade vibration has not been thoroughly investigated. The inclusion of the coupling terms in the wind turbine dynamics equations helps us understand the phenomenon of rotor oscillation due to blade vibration and possibly diagnose faults. In this study, a dynamics model of a rotor-blade system for a horizontal axis wind turbine (HAWT), which describes the coupling terms between the blade elastic movement and rotor gross rotation, is developed. The model is developed by using Lagrange's approach and the finite-element method has been adopted to discretize the blade. This model captures two-way interactions between aerodynamic wind flow and structural response. On the aerodynamic side, both steady and unsteady wind flow conditions are considered. On the structural side, blades are considered to deflect in both flap and edge directions while the rotor is treated as a rigid body. The proposed model is cross-validated against a model developed in the simulation software fatigue, aerodynamics, structure, and turbulence (fast). The coupling effects are excluded during the comparison since fast does not include these terms. Once verified, we added coupling terms to our model to investigate the effects of blade vibration on rotor movement, which has direct influence on the generator behavior. It is illustrated that the inclusion of coupling effects can increase the sensitivity of blade fault detection methods. The proposed model can be used to investigate the effects of different terms as well as analyze fluid–structure interaction.

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Nonlinear dynamic modeling and response analysis of a rotor–blade system with whirling motion

Nonlinear Dynamics ◽

10.1007/s11071-019-05238-5 ◽

2019 ◽

Vol 98 (2) ◽

pp. 953-970 ◽

Cited By ~ 2

Author(s):

Jaewon Kim ◽

Jun-Gi Hong ◽

Jintai Chung

Keyword(s):

Dynamic Modeling ◽

Nonlinear Dynamic ◽

Rotor Blade ◽

Response Analysis ◽

Whirling Motion ◽

Blade System ◽

Nonlinear Dynamic Modeling

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Active control system for a rotor blade trailing-edge flap

10.1117/12.388848 ◽

2000 ◽

Cited By ~ 2

Author(s):

Marc Duvernier ◽

Livier Reithler ◽

Jean Y. Guerrero ◽

Rinaldo A. Rossi

Keyword(s):

Control System ◽

Active Control ◽

Rotor Blade ◽

Trailing Edge ◽

Trailing Edge Flap ◽

Active Control System

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Reduced Modeling for Turbine Rotor-Blade Coupled Bending Vibration Analysis

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4004145 ◽

2011 ◽

Vol 134 (2) ◽

Cited By ~ 3

Author(s):

Akira Okabe ◽

Takeshi Kudo ◽

Koki Shiohata ◽

Osami Matsushita ◽

Hiroyuki Fujiwara ◽

...

Keyword(s):

Natural Frequency ◽

Rotor Blade ◽

High Efficiency ◽

Sliding Mode ◽

Coupled System ◽

Bending Vibration ◽

Mass System ◽

Joint Power ◽

Nodal Diameter ◽

Blade System

In a traditional turbine-generator set, rotor shaft designers and blade designers have their own models and design process which neglects the coupled effect. Since longer blade systems have recently been employed (Saito et al. 1998, “Development of a 3000 rpm 43-in. last stage blade with high efficiency and reliability,” International Joint Power Generation Conference, pp. 89–96.) for advanced turbine sets to get higher output and efficiency, additional consideration is required concerning rotor bending vibrations coupled with a one-nodal (k = 1) blade system. Rotor-blade coupled bending conditions generally include two types so that the parallel and tilting modes of the shaft vibrations are respectively coupled with in-plane and out-of-plane modes of blade vibrations with a one-nodal diameter (k = 1). This paper proposes a method to calculate the natural frequency of a shaft blade coupled system. According to this modeling technique, a certain blade mode is reduced to a single mass system, which is connected to the displacement and angle motions of the shaft. The former motion is modeled by the m-k system to be equivalent to the blade on the rotating coordinate. The latter motion is commonly modeled in discrete form using the beam FEM on an inertia coordinate. Eigenvalues of the hybrid system covering both coordinates provide the natural frequency of the coupled system. In order to solve the eigenfrequencies of the coupled system, a tracking solver method based on sliding mode control concept is used. An eight-blade system attached to a cantilever bar is used for an example to calculate a coupled vibration with a one-nodal diameter between the blade and shaft.

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Lifting multi-blade flows with interaction

Journal of Fluid Mechanics ◽

10.1017/s0022112000008673 ◽

2000 ◽

Vol 415 ◽

pp. 203-226 ◽

Cited By ~ 14

Author(s):

R. G. A. BOWLES ◽

F. T. SMITH

Keyword(s):

Rotor Blade ◽

Periodic Boundary ◽

Leading Edge ◽

Main Flow ◽

Flow Properties ◽

Central Motion ◽

Blade System ◽

Flow Through ◽

Lift And Drag ◽

Separating Flows

Planar flow past multiple successive blades and wakes is studied for nearly aligned configurations with normal non-symmetry inducing lift. The typical blade lies relatively near the centreline of the oncoming wake from the preceding blade. The central motion over a wide parameter range is in condensed periodic boundary layers and wakes with fixed displacement, buried within surrounding incident shear flow. This is accompanied, however, by streamwise jumps in the pressure, velocity and mass flux, across the leading edge of each blade, a new and surprising feature which is supported by the combination of incident shears and a solid surface and which is related to the normal flow through the multi-blade system. The leading-edge jumps are required in order to satisfy the equi-pressure condition at the trailing edge. Computational results include separating flows and show the lift and drag, and these are followed by a short-blade analysis which captures the main flow properties explicitly. The results agree qualitatively with experiments and direct simulations for rotor blade flows. The jump feature also extends for example to a single blade immersed in the relatively large wake of an upstream blade.

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