Prevention of Low-Frequency Vibration of High-Capacity Steam Turbine Units by Squeeze-Film Damper

1998 ◽  
Vol 120 (2) ◽  
pp. 391-396 ◽  
Author(s):  
H. Kanki ◽  
Y. Kaneko ◽  
M. Kurosawa ◽  
T. Yamamoto
Keyword(s):  
High Pressure ◽  
High Capacity ◽  
Low Frequency ◽  
Field Tests ◽  
Rotor System ◽  
Operating Conditions ◽  
Squeeze Film ◽  
High Pressure Turbine ◽  
Squeeze Film Damper ◽  
Low Frequency Vibration

The cause of the low-frequency vibration (subsynchronous vibration) of a high-pressure turbine was investigated by the analytical study and vibration exciting test for the actual machine in operation. From the results, it is found that the low-frequency vibration is caused by the decrease of the rotor system damping at high-loading operating conditions. As a countermeasure, a squeeze-film damper is designed in order to increase the damping of the rotor system. After the verification test of the squeeze-film damper’s capability in the workshop, it was installed on the actual turbine. Vibration exciting tests for the high-pressure turbine under the actual operating conditions were carried out. These field tests confirmed that the damping of the rotor system was increased as expected in the design and consequently the low-frequency vibrations disappeared completely under all operating conditions.

scholarly journals Prevention of Low-Frequency Vibration of High-Capacity Steam Turbine Units by Squeeze-Film Damper

1997 ◽  
Author(s):  
H. Kanki ◽  
Y. Kaneko ◽  
M. Kurosawa ◽  
T. Yamamoto
Keyword(s):  
High Pressure ◽  
High Capacity ◽  
Low Frequency ◽  
Field Tests ◽  
Rotor System ◽  
Operating Conditions ◽  
Squeeze Film ◽  
High Pressure Turbine ◽  
Squeeze Film Damper ◽  
Low Frequency Vibration

The cause of the low-frequency vibration (subsynchronous vibration) of a high pressure turbine was investigated by the analytical study and vibration exciting test for the actual machine in operation. From the results, it is found that the low-frequency vibration is caused by the decrease of the rotor system damping at high-loading operating conditions. As a countermeasure, a squeeze-film damper is designed in order to increase the damping of the rotor system. After the verification test of the squeeze-film damper’s capability in the workshop, it was installed on the actual turbine. Vibration exciting tests for the high pressure turbine under the actual operating conditions were carried out. These field tests confirmed that the damping of the rotor system was increased as expected in the design and consequently the low-frequency vibrations disappeared completely under all operating conditions.

Prevention of Low-Frequency Vibration of High-Capacity Steam Turbine Units

1997 ◽  
Author(s):  
H. Kanki ◽  
Y. Kaneko ◽  
M. Kurosawa ◽  
T. Yamamoto ◽  
Y. Yamamoto ◽  
...  
Keyword(s):  
High Pressure ◽  
High Capacity ◽  
Low Frequency ◽  
Field Tests ◽  
Operating Conditions ◽  
Squeeze Film ◽  
High Pressure Turbine ◽  
Solution Approach ◽  
Vibration Excitation ◽  
Low Frequency Vibration

Abstract The causes of low-frequency vibration (subsynchronous vibration) of a high pressure turbine were investigated analytically and also via vibration excitation tests on actual machines under operation. From the results, it was concluded that low-frequency vibrations may be caused by either the decrease of the rotor system damping or by external forces, such as flow disturbance in the control stage and the rubbing between the rotor and casing. After identifying the cause of the low-frequency vibration, appropriate countermeasures such as installation of a squeeze-film damper and modification of valve opening sequence were taken. Vibration measurements and vibration excitation tests for the high pressure turbine under actual operating conditions were carried out in order to verify the validity of the countermeasures. These field tests confirmed that the problems of low-frequency vibration can be solved completely by taking the appropriate countermeasure depending on the cause of the vibration. This paper presents some field experiences of low-frequency vibration and the effective solution approach.

Investigation of the Transient Response of a Dual-Rotor System With Intershaft Squeeze Film Damper

1985 ◽  
Author(s):  
Qihan Li ◽  
James F. Hamilton
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Transient Response ◽  
Synthesis Method ◽  
Gas Turbine Engine ◽  
Rotor System ◽  
Squeeze Film ◽  
High Pressure Turbine ◽  
Turbine Engine ◽  
Squeeze Film Damper

A method is presented for calculating the dynamics of a dual-rotor gas turbine engine equipped with a flexible intershaft squeeze-film damper. The method is based on the functional expansion component synthesis method. The transient response of the rotor due to a suddenly applied unbalance in the high-pressure turbine under different steady-speed operations is calculated. The damping effects of the intershaft damper and stability of the rotor system are investigated.

Investigation of the Transient Response of a Dual-Rotor System With Intershaft Squeeze-Film Damper

1986 ◽  
Vol 108 (4) ◽  
pp. 613-618 ◽  
Author(s):  
Qihan Li ◽  
J. F. Hamilton
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Transient Response ◽  
Synthesis Method ◽  
Gas Turbine Engine ◽  
Rotor System ◽  
Squeeze Film ◽  
High Pressure Turbine ◽  
Turbine Engine ◽  
Squeeze Film Damper

A method is presented for calculating the dynamics of a dual-rotor gas turbine engine equipped with a flexible intershaft squeeze-film damper. The method is based on the functional expansion component synthesis method. The transient response of the rotor due to a suddenly applied imbalance in the high-pressure turbine under different steady-speed operations is calculated. The damping effects of the intershaft damper and stability of the rotor system are investigated.

scholarly journals Analysis on Influences of Squeeze Film Damper on Vibrations of Rotor System in Aeroengine

2022 ◽  
Vol 12 (2) ◽  
pp. 615
Author(s):  
Haobo Wang ◽  
Yulai Zhao ◽  
Zhong Luo ◽  
Qingkai Han
Keyword(s):  
High Speed ◽  
Vibration Suppression ◽  
Rotor System ◽  
Operating Conditions ◽  
Squeeze Film ◽  
Lumped Mass ◽  
Squeeze Film Damper ◽  
Rotor Systems ◽  
Vibration Responses ◽  
Stiffness And Damping

Squeeze film damper (SFD) is widely used in the vibration suppression of aeroengine rotor systems, but will cause complex motions of the rotor system under specific operating conditions. In this paper, a lumped-mass dynamic model of the high-pressure rotor system in an aeroengine is established, and the nonlinear stiffness and damping formula of SFD are introduced into the above model. The vibration responses of the rotor system under different rotating speeds and with different unbalances are investigated numerically, and the influence of SFD on the rotor system vibration and the change of suppression ability are compared and analyzed. The results show that in the case of high speed, together with a small unbalance, the rotor system will perform a complex vibration or a bistable vibration due to SFD. If the unbalance is properly increased under the same case of high speed, the vibration of the rotor becomes single-harmonic and the bistable vibration disappears. The research results can provide a helpful reference for analyzing complex vibration mechanisms of the rotor system with SFD and achieving an effective vibration suppression through unbalance regulation.

Validation of MISES Two-Dimensional Boundary Layer Code for High-Pressure Turbine Aerodynamic Design

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Philip L. Andrew ◽  
Harika S. Kahveci
Keyword(s):  
Boundary Layer ◽  
High Pressure ◽  
Operating Cost ◽  
Design Tool ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
High Pressure Turbine ◽  
Reduce Operating Cost ◽  
Wide Range ◽  
Dimensional Boundary

Avoiding aerodynamic separation and excessive shock losses in gas turbine turbomachinery components can reduce fuel usage and thus reduce operating cost. In order to achieve this, blading designs should be made robust to a wide range of operating conditions. Consequently, a design tool is needed—one that can be executed quickly for each of many operating conditions and on each of several design sections, which will accurately capture loss, turning, and loading. This paper presents the validation of a boundary layer code, MISES, versus experimental data from a 2D linear cascade approximating the performance of a moderately loaded mid-pitch section from a modern aircraft high-pressure turbine. The validation versus measured loading, turning, and total pressure loss is presented for a range of exit Mach numbers from ≈0.5 to 1.2 and across a range of incidence from −10 deg to +14.5 deg relative to design incidence.

Nonlinear Dynamic Study on Effects of Rub-Impact Caused by Oil-Rupture in a Multi-Shafts Turbine With a Squeeze Film Damper

2014 ◽  
Author(s):  
T. N. Shiau ◽  
C. R. Wang ◽  
D. S. Liu ◽  
W. C. Hsu ◽  
T. H. Young
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Equations Of Motion ◽  
Rotor System ◽  
Squeeze Film ◽  
Speed Ratio ◽  
Frequency Spectra ◽  
Squeeze Film Damper ◽  
Assumed Mode Method ◽  
Nonlinear Dynamic Behavior

An investigation is carried out the analysis of nonlinear dynamic behavior on effects of rub-impact caused by oil-rupture in a multi-shafts turbine system with a squeeze film damper. Main components of a multi-shafts turbine system includes an outer shaft, an inner shaft, an impeller shaft, ball bearings and a squeeze film damper. In the squeeze film damper, oil forces can be derived from the short bearing approximation and cavitated film assumption. The system equations of motion are formulated by the global assumed mode method (GAMM) and Lagrange’s approach. The nonlinear behavior of a multi-shafts turbine system which includes the trajectories in time domain, frequency spectra, Poincaré maps, and bifurcation diagrams are investigated. Numerical results show that large vibration amplitude is observed in steady state at rotating speed ratio adjacent to the first natural frequency when there is no squeeze film damper. The nonlinear dynamic behavior of a multi-shafts turbine system goes in its way into aperiodic motion due to oil-rupture and it is unlike the usual way (1T = >2T = >4T = >8T etc) as compared to one shaft rotor system. The typical routes of bifurcation to aperiodic motion are observed in a multi-shafts turbine rotor system and they suddenly turn into aperiodic motion from the periodic motion without any transition. Consequently, the increasing of geometric or oil parameters such as clearance or lubricant viscosity will improve the performance of SFD bearing.

Dynamic Analysis of a Coupled Dual-Rotor With Squeeze Film Damper Considering Sudden Unbalance

2021 ◽  
Author(s):  
Ying Cui ◽  
Yuxi Huang ◽  
Guogang Yang ◽  
Yongliang Wang ◽  
Han Zhang
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Rotor System ◽  
Lubricating Oil ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Oil Viscosity ◽  
Squeeze Film Damper ◽  
Damping Effect ◽  
Bistable State

Abstract A nonlinear multi-degree-of-freedom dynamic model of a coupled dual-rotor system with an intershaft bearing and uncentralized squeeze film damper is established by using finite element method. Based on the model, the critical speed characteristic diagram and vibration modes of the system were calculated. The steady-state unbalance response is obtained by using Newmark-β algorithm. The numerical results show the effect of SFD position in the dual-rotor system on response amplitude. It is found that with the decrease of radial clearance and the increase of length-diameter ratio and lubricating oil viscosity, the damping effect of SFD is enhanced and the bistable state phenomenon can be suppressed. The transient response of the system in case of sudden unbalance occurring at the fan was simulated by applying a step function. It is demonstrated that the SFD can effectively reduce the duration and maximum amplitude of the transient process, but at certain speeds, the SFD will increase the amplitude after the system returns to steady state, the damping effect on the transient response is also enhanced with the increase of length-diameter and the decrease of radial clearance, and with the increase of the sudden unbalance value, the response is more likely to stabilized at the high amplitude state of the bistable state.

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