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.

scholarly journals Parameter Analysis of an Intershaft Dual-Rotor with the Application of Squeeze Film Dampers

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Huizheng Chen ◽  
Shun Zhong ◽  
Zhenyong Lu ◽  
Yushu Chen ◽  
Xiyu Liu
Keyword(s):  
Vibration Suppression ◽  
Rotor System ◽  
Parameter Analysis ◽  
Dynamical Analysis ◽  
Squeeze Film ◽  
Physical Parameters ◽  
Squeeze Film Damper ◽  
Rotor Systems ◽  
Squeeze Film Dampers ◽  
Frequency Curves

The squeeze film damper is usually adopted in the rotor system to suppress the vibrating motion of the rotor system. In this work, not only are the physical parameters of the squeeze film damper analyzed but also the system parameters, like the number of squeeze film dampers used and squeeze film damper implementation positions, are analyzed. The amplitude-frequency curves are obtained by conducting the simulation of a dual-rotor, intershaft, and oil film force concatenated model. Through the analysis and comparisons of the results, the vibration suppression effects of the squeeze film damper with different parameter configurations are analyzed and summarized. This work contributes to further optimization and dynamical analysis work on rotor systems with the application of the squeeze film damper.

Ball bearing turbocharger vibration management: application on high speed balancer

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Ball Bearing ◽  
Squeeze Film ◽  
Design And Technology ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Bearing Loads ◽  
Stiffness And Damping

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

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.

Development of an Efficient Oil Film Damper for Improving the Control of Rotor Vibration

1991 ◽  
Vol 113 (4) ◽  
pp. 557-562 ◽  
Author(s):  
Shiping Zhang ◽  
Litang Yan
Keyword(s):  
High Speed ◽  
Porous Metal ◽  
Porous Matrix ◽  
Squeeze Film ◽  
Oil Film ◽  
Squeeze Film Damper ◽  
Outer Race ◽  
Typical Experiment ◽  
Stiffness And Damping ◽  
Film Stiffness

An efficient oil film damper known as a porous squeeze film damper (PSFD) was developed for more effective and reliable vibration control of high-speed rotors based on the conventional squeeze film damper (SFD). The outer race of the PSFD is made of permeable sintered porous metal materials. The permeability allows some of the oil to permeate into and seep out of the porous matrix, with remarkable improvement of the squeeze film damping properties. The characteristics of PSFD oil film stiffness and damping coefficients and permeability, and also, the steady-state unbalance response of a simple rigid rotor and flexible Jeffcott’s rotor supported on PSFD and SFD are investigated. A typical experiment is presented. Investigations show that the nonlinear vibration characteristics of the unpressurized SFD system such as bistable jump phenomena and “lockup” at rotor pin-pin critical speeds could be avoided and virtually disappear under much greater unbalance levels with properly designed PSFD system. PSFD has the potential advantage of operating effectively under relatively large unbalance conditions.

Dynamical Behaviors of Hybrid Squeeze Film Damper for Rotor System Vibration Control

1995 ◽  
Author(s):  
Zhu Changsheng
Keyword(s):  
Rotor System ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Rigid Rotor ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Dynamical Behaviors ◽  
System Vibration ◽  
Stiffness And Damping ◽  
Film Stiffness

Abstract The behaviors of oil film stiffness and damping coefficients of the deep multi-recessed hybrid squeeze film damper (HSFD) with the orifices compensated are first analysed in this paper. The control ability of the HSFD on the rotor system vibrations is studied theoretically and experimentally with a rigid rotor system supported on the HSFD, and compared with that of the conventional squeeze film damper (SFD). Investigation shows that the HSFD not only can significantly improve the high nonlinearity of the SFD, but also can effectively control the rotor vibrational amplitudes, especially for larger rotor unbalance levels and radial clearance ratios, as compared with the SFD.

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.

Study of Transient Characteristic of a Simple Rigid Rotor Supported on a Squeeze Film Damper With Valvular Metal Rubber Squeeze Film Ring

2007 ◽  
Author(s):  
Yanhong Ma ◽  
Jie Hong ◽  
Dayi Zhang ◽  
Hong Wang
Keyword(s):  
High Speed ◽  
Squeeze Film ◽  
Impact Loads ◽  
Rigid Rotor ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Metal Rubber ◽  
Stiffness And Damping ◽  
Film Stiffness ◽  
Blade Loss

An efficient oil film damper known as a squeeze film damper with valvular metal rubber squeeze film ring (SFD/VMR) was developed for more effective and reliable vibration control, and especially for improving the blade loss dynamics of high-speed rotors based on the conventional squeeze film damper (SFD). The immobile squeeze film ring of the SFD was replaced by the elastic squeeze film ring with the valvular metal rubber subassembly (VMR) of the SFD/VMR. The squeeze film force properties of the SFD/VMR was improved, because it can passively adjust the squeeze film clearance by taking advantage of the elastic deformation of the VMR and can control the squeeze film clearance in a suitable range. The characteristics of squeeze film stiffness and damping coefficients, as well as the steady-state unbalance response of a simple rigid rotor supported on SFD/VMR and SFD, were reported in a previous literature[1]. In this paper, the transient response of the rigid rotor supported on SFD/VMR and SFD subjected to sudden unbalance of blade loss are inverstigated. Time transient simulation and experimental results indicated that SFD/VMR can operate effectively under much greater unbalance compared with SFD, especially under relative large impact loads of blade loss. The SFD/VMR can suppress the occurrence of the nonlinear vibration phenomenon markedly, such as the bistable jump up phenomenon. Furthermore, the effective eccentricities of SFD/VMR with small transfer ratio (T<1.2) extend to two times of SFD, and optimum film stiffness and damping distribution within the whole film clearance can be achieved.

scholarly journals An Improved Squeeze Film Damper for Rotor Vibration Control: Theoretical Results

1994 ◽  
Author(s):  
J. Y. Zhao ◽  
I. W. Linnett ◽  
E. J. Hahn
Keyword(s):  
Operating Conditions ◽  
Outer Ring ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Constant Stiffness ◽  
Wide Range ◽  
Squeeze Film Dampers ◽  
Secondary Support ◽  
Stiffness And Damping ◽  
Theoretical Results

This paper proposes an improved squeeze film damper which will prevent the bistable operation associated with conventional squeeze film dampers at large unbalances and/or at small bearing parameters. It consists of a conventional squeeze film damper with a flexibly supported outer ring. This secondary flexible support is considered to be massless, and to have a constant stiffness and damping. The effectiveness of this damper in preventing bistable operation is investigated over a wide range of operating conditions for a rigid rotor supported on a centrally preloaded squeeze film damper. It is shown that depending on relevant parameters such as the stiffness ratio between the secondary support and the retaining spring, the damping coefficient of the support, and the mass ratio between the damper outer ring and the rotor, this proposed damper is very effective in preventing bistable operation even for high unbalance conditions.

scholarly journals Passive vibration reduction of a squeeze film damper for a rotor system with fit looseness between outer ring and housing

2020 ◽  
pp. 146134842096869
Author(s):  
Haifei Wang
Keyword(s):  
Nonlinear Vibration ◽  
Vibration Reduction ◽  
Research Work ◽  
Contact Problems ◽  
Rotor System ◽  
Outer Ring ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Response Characteristics ◽  
Vibration Responses

Clearances between bearing outer ring and sleeve can generally be maintained to provide a margin for the thermal expansion of the bearings. However, temperature variation, improper assembly and long-term vibration can enlarge the clearances and accelerate mechanical wear, leading to what is known as the fit looseness fault. Therefore, it is important to study a fit looseness fault model and investigate how to control the vibration coming from the fit looseness fault. In this paper, a Jeffcott rotor system with three disks was modeled as a single unit. A fit looseness model was applied in the whole rotor model to study the contact problems and response characteristics using a numerical integration method. Then, a squeeze film damper model was applied to assess the vibration reduction effects on the whole rotor system with the fit looseness fault. By comparing the results of the fit looseness fault without squeeze film damper and with squeeze film damper, it is found that the squeeze film damper can reduce nonlinear vibration responses effectively generated by the fit looseness fault for the nonlinear contact. This research work contributes to understanding the mechanism of fit looseness fault and controlling strong nonlinear vibration responses due to the fit clearances.

A Dynamic Analysis of a Dual Clearance Squeeze Film Damper

2010 ◽  
Author(s):  
L. Moraru ◽  
T. G. Keith ◽  
F. Dimofte ◽  
S. Cioc ◽  
N. Ene ◽  
...  
Keyword(s):  
High Speed ◽  
Reynolds Equation ◽  
Numerical Solutions ◽  
Rotating Machinery ◽  
Operating Conditions ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Squeeze Film Dampers ◽  
Abnormal Operating Conditions ◽  
Oil Films

Squeeze film dampers (SFD) are devices utilized to control the shafts of high-speed rotating machinery. A dual squeeze film damper (DSFD) consists of two squeeze film bearings that are separated by a sleeve, which is released when the rotor experiences abnormal operating conditions. In this part of our study of DSFD we analyze the case when both the inner and the outer oil films are active. We present computed and measured unbalance responses of a shaft supported in DSFD. The oil forces which are utilized in the calculation of the unbalance response are obtained from numerical solutions of the Reynolds equation. A finite-difference algorithm is utilized for solving the pressure equation within the calculation of the dynamic response of the shaft.

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