The coupled vibration in a rotating multi-disk rotor system with grouped blades

2014 ◽  
Vol 28 (5) ◽  
pp. 1653-1662 ◽  
Author(s):  
YiJui Chiu ◽  
Chia-Hao Yang
Keyword(s):  
Rotor System ◽  
Coupled Vibration ◽  
Grouped Blades

Method of Coupled Vibration Control for Dual Rotor System With Inter-Shaft Bearing

2021 ◽  
Author(s):  
Yanhong Ma ◽  
Chenglong Shi ◽  
Bo Sun ◽  
Jie Hong
Keyword(s):  
Vibration Control ◽  
Mode Coupling ◽  
Weight Ratio ◽  
Low Pressure ◽  
Rotor System ◽  
Coupled Vibration ◽  
Coupling Vibration ◽  
Rotor Systems ◽  
Modal Coupling ◽  
Coupling Characteristics

Abstract Structural layout scheme of dual rotor system with inter-shaft bearing plays an important role in reducing the bearing frame and structure weight of areo-engine. This kind of scheme is often used in the design of high thrust-weight ratio turbofan engine. However, the inter-shaft bearing will cause the direct interaction of the force and displacement between the high and low pressure rotor systems, contributing to the coupling of the dynamic characteristics of two rotor systems. The coupling may eventually lead to the failure of the rotor displacement control, loss of the robustness of the connection structure or excessive dynamic load of the bearing. The main purpose of this paper is to, firstly study and quantitatively evaluate the coupling characteristics of the dual rotor system, secondly obtain the correlation between the structural feature parameters such as the position of the inter-shaft bearing and the coupling vibration or interactive excitation characteristics of the system, finally propose the coupling vibration control method of dual rotor system. The dynamic model of dual rotor system with inter-shaft bearing is established. The modal frequencies and modes of dual rotor system with or without coupling are analyzed and compared. The results illustrate the complexity of coupled vibration of high pressure and low pressure rotors. Then modal coupling characteristics evaluation parameter of dual rotor system based on energy distribution relationship is proposed. Using the coupling factor defined, the correlation between the inter-shaft bearing support feature and the modal coupling characteristics is discussed. The results show that, placing the inter-shaft bearing near the mass center of low pressure turbine can effectively restrain the mode coupling, meanwhile the proportion of bearing strain energy can also reflect the mode coupling characteristics of dual rotor system to a certain extent. Then a method of controlling the response coupled vibration of dual rotor system with inter-shaft bearing, based on the principle of mode superposition, is proposed. An example verifies the method can control the response coupling vibration of dual rotor system in wide speed range and under complex excitation conditions.

Roll-Yaw Coupled Vibration of the Rotor System With Breathing Crack and Unbalance Mass

2015 ◽  
Author(s):  
J. Zhao ◽  
H. A. DeSmidt ◽  
M. Peng ◽  
W. Yao
Keyword(s):  
Coupling Effect ◽  
Rotor System ◽  
Crack Model ◽  
Clear Understanding ◽  
Coupled Vibration ◽  
Breathing Crack ◽  
Energy Concept ◽  
Vibration Responses ◽  
Rolling Rate ◽  
Rotor Model

This paper develops a new finite element rotor model with consideration of the coupling effect of rolling and yawing motion. The crack model is built using released strain energy concept in fracture mechanics. The nonlinear breathing behavior of cracks on the rotor shaft is simulated through Zero Stress Intensity Factor (SIF) method. The vibration responses of rotor system are solved by Newmark Integration method for both nominal and damaged system. With the yawing motion, the additional force will be induced for beam element and center disk. Incorporated with breathing crack model, the breathing behavior of crack is comprehensively studied in terms of the rolling rate, yawing rate and yawing acceleration. The clear understanding of crack breathing behavior is beneficial for the damage detection and health monitoring of the rotor system.

scholarly journals Effects of Surface Waviness on the Nonlinear Vibration of Gas Lubricated Bearing-Rotor System

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Jian Li ◽  
Shaoqi Yang ◽  
Xiaoming Li ◽  
Qing Li
Keyword(s):  
Nonlinear Dynamic ◽  
Dynamic Performance ◽  
Engineering Application ◽  
Axial Direction ◽  
Rotor System ◽  
Circumferential Direction ◽  
Coupled Vibration ◽  
Surface Waviness ◽  
The Stability ◽  
Gas Bearing

This paper presents the effects of the surface waviness on the nonlinear dynamic performance of a gas bearing-rotor system. The coupled vibration with the elastomer is taken into consideration to fit the actual engineering application. The effects of the directions, the amplitudes, and the numbers of waves to the nonlinear dynamic performance are investigated. The results show that the existence of the surface waviness in the circumferential direction can improve the stability of the system obviously. But the surface waviness in the axial direction is damage to the system. The nonlinear dynamic performance of the system is insensitive to the number of surface waviness. The increase of the amplitude of the waviness in circumferential direction can improve the stability of the system.

Three methods for studying coupled vibration in a multi flexible disk rotor system

2017 ◽  
Vol 31 (11) ◽  
pp. 5219-5229 ◽  
Author(s):  
Yi-Jui Chiu ◽  
Xiao-Yun Li ◽  
Yi-Cheng Chen ◽  
Sheng-Rui Jian ◽  
Chia-Hao Yang ◽  
...  
Keyword(s):  
Rotor System ◽  
Coupled Vibration ◽  
Flexible Disk

Experimental Study of Torsional-Bending Coupled Vibration of a Rotor System With a Bladed Disk

2013 ◽  
Author(s):  
Takeshi Kudo ◽  
Koki Shiohata ◽  
Osami Matsushita ◽  
Hiroyuki Fujiwara ◽  
Akira Okabe ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Torsional Vibration ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Active Magnetic Bearing ◽  
Coupled Vibration ◽  
Bending Vibration ◽  
Nodal Diameter ◽  
Rotor Systems ◽  
Bladed Disk

An experimental investigation was conducted to confirm the bending-torsion coupled vibration of a rotor system with a bladed disk. For a rotor with relatively long blades such as in the latest low-pressure steam turbines, coupled vibration with shaft torsional vibration represents the bladed disk natural frequency of a nodal diameter (k) of zero (umbrella mode). Today this well-known behavior is reflected in the design of steam turbine rotor systems to prevent the blade vibration resonance due to torque excitation caused by the electric power grid, a standard for which is proposed by ISO 22266-1. The bending-torsion coupled resonance of rotor systems occurs, however, under specific conditions due to rotor unbalance. When the rotor’s rotational speed (Ω) is equal to the sum/difference of the bending natural frequency (ωb) and torsional natural frequency (ωθ), namely, Ω = ωθ ± ωb, there is coupled resonance, which was experimentally observed with a rotor with a relatively simplified shape. In this study, the test apparatus for a flexible rotor system equipped with a shrouded bladed disk driven by an electric motor was constructed to confirm the vibration characteristics, by envisioning the bending-torsion coupled resonance as applied to actual rotor systems of turbo machinery. A radial active magnetic bearing (AMB) was employed to support the rotor by controlling bearing stiffness and damping, and applying lateral directional excitation of forward and backward whirl to the rotor. A servomotor was also equipped at the end of the rotor system to excite the torsional vibration. The resonance of a bladed disk with nodal diameter (k) of zero, which was coupled with the rotor’s torsional vibration, was observed under the above condition (Ω = ωθ − ωb) through AMB excitation of the rotor’s bending natural frequency. Conversely, the torsional excitation caused by the servomotor was confirmed as causing the coupled resonance of rotor bending vibration.

scholarly journals Investigation on nonlinear lateral-torsional coupled vibration of a rotor system with substantial unbalance

2020 ◽  
Vol 33 (6) ◽  
pp. 1642-1660 ◽  
Author(s):  
Jie HONG ◽  
Pingchao YU ◽  
Yanhong MA ◽  
Dayi ZHANG
Keyword(s):  
Rotor System ◽  
Coupled Vibration
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