Bifurcation and chaos of the bladed overhang rotor system with squeeze film dampers

Cao, Dengqing; Wang, LiGang; Chen, Yushu; Huang, Wenhu

doi:10.1007/s11431-009-0039-y

Cited by 10 publications

(3 citation statements)

References 15 publications

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“…The ellipticity ratiod is a key parameter in an elliptical bearing. In general, the dynamic responses at each bearing centre and disc have very similar behaviour as indicated in reference [19]. Therefore, in the following discussion, the dynamic behaviours of the left bearing centre are taken as a typical example.…”

Section: Case Study Ii: the Rotor-bearing System For A 200 Mw Turbine Setmentioning

confidence: 90%

A new fluid film force model of elliptical bearing: Modelling and case studies

Cao

Huang

2010

Proceedings of the Institution of Mechanical Engineers, Part J:

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The fluid film force model plays a very important role in the non-linear dynamic analysis of a rotor-bearing system. Based on the assumption of the short journal bearing, the fluid film pressure distribution in an elliptical bearing is obtained in terms of the Reynolds equation and the dynamic Gümbel boundary conditions. According to the structural characteristic of elliptical bearing and the integral of fluid film pressure distribution, the fluid force model is formulated. A numerical experiment on the Jeffcott flexible-rotor model is given to show that the model is effective when length-diameter ratio is smaller than 0.6, and the computing cost for dynamical response of rotor-bearing is reduced. Finally, the dynamical behaviour and bifurcation of a 200 MW turbine set are numerically obtained applying the new fluid film force model.

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Section: Case Study Ii: the Rotor-bearing System For A 200 Mw Turbine Setmentioning

confidence: 90%

A new fluid film force model of elliptical bearing: Modelling and case studies

Cao

Huang

2010

Proceedings of the Institution of Mechanical Engineers, Part J:

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“…During the operation of the steam turbine, the turbine blades are affected by the harsh environment such as high pressure, high temperature, high speed and working in wet condition. 5,6 Also, combined with the effect of centrifugal force, airflow excitation force and high-speed erosion of water droplets, turbine blades are prone to vibrate during operation, resulting in steam turbine accidents. 7,8 In these accidents, accidents caused by damage of turbine blades due to vibration account for the major of the total accidents.…”

Section: Introductionmentioning

confidence: 99%

Study on the collision dynamics of integral shroud blade for high-pressure turbine in different integral shroud clearance distance

Zhang

Wang

Qin

et al. 2021

Noise & Vibration Worldwide

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In steam turbine, turbine blades are prone to vibrate during operation, resulting in steam turbine accidents. The most common method for reducing the vibration of steam turbine blades is to design an integral shroud for blade which is termed as integral shroud blade. Most previous studies simplified straight integral blades into cantilever beam and used harmonic response analysis method to simulate the vibration response of blades. This method is suitable for simulating straight blade vibration under harmonic force conditions. For twisted blades, accurate results are hard to acquire and the specific collision process cannot be simulated. In order to observe the collision process on a microscopic scale and explore its collision damping mechanism, this study evaluated the collision process of twisted blades with different integral shroud clearance distance based on LS-DYNA software. The collision process for a two-blade system and a three-blade system with integral shroud clearance distance from 0.1 mm to 0.5 mm has been simulated. The results indicated that integral shroud clearance distance have opposite vibration damping effect when the blade under the condition of forced vibration and free vibration. For the two-blade system, the optimal integral shroud clearance distance is 0.4 mm for forced vibration condition and 0.1 mm for free vibration condition. For the three-blade system, the optimal integral shroud clearance distance is 0.1 mm for forced vibration condition and 0.5 mm for free vibration condition.

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“…Chun and Lee [20] studied the effects of blade parameters on the coupled vibration of the blade-rotor system. Cao et al [21] simplified the blade into a cantilever beam structure and deeply studied the dynamic model of the blade-rotor system with the consideration of the factors such as sliding bearing, squeeze film damper, and gyro effect, respectively. e influence of blade parameters on the dynamic characteristics of the system showed that the blade parameters have a significant influence on the bifurcation characteristics of the coupled system, and the blade would change the instability speed of the system.…”

Section: Introductionmentioning

confidence: 99%

Modeling and Dynamic Characteristics Analysis of Blade-Disk Dual-Rotor System

Zhong²,

Chen

et al. 2020

Complexity

Self Cite

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In this paper, a simplified dynamic model of a dual-rotor system coupled with blade disk is built, and the effects of blade parameters of an aircraft engine on the dynamic characteristics of a dual-rotor system are studied. In the methodology, the blade is simplified as a cantilever structure, and the dynamical equations are obtained by the means of a finite element method. The amplitude-frequency response curves and orbits of shaft centre-vibration shape diagram are used to analyze the effects of blade parameters on dynamic characteristics of a dual-rotor system. The results indicate that the properties of the blades have huge impacts on the critical speed and other dynamic characteristics of the system. With an increase of the length of the blade, the second-order critical speed decreases obviously, but the first-order critical speed is almost invariant; this means that the blades attached on the low-pressure compressor do not affect the first-order critical speed of the dual-rotor system. Meanwhile, note that the high-pressure rotor and low-pressure turbine rotor can excite the first-order resonance of the dual-rotor system, while the low-pressure compressor rotor can only excite the second-order resonance, and then the dynamic model of this six-point support dual-rotor system can further be simplified as a relatively independent single-rotor system with one disk and a four-support dual-rotor system with dual disks.

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Bifurcation and chaos of the bladed overhang rotor system with squeeze film dampers

Cited by 10 publications

References 15 publications

A new fluid film force model of elliptical bearing: Modelling and case studies

A new fluid film force model of elliptical bearing: Modelling and case studies

Study on the collision dynamics of integral shroud blade for high-pressure turbine in different integral shroud clearance distance

Modeling and Dynamic Characteristics Analysis of Blade-Disk Dual-Rotor System

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