The Optimal Design of Squeeze Film Dampers for Flexible Rotor Systems

1988 ◽  
Vol 110 (2) ◽  
pp. 166-174 ◽  
Author(s):  
W. J. Chen ◽  
M. Rajan ◽  
S. D. Rajan ◽  
H. D. Nelson
Keyword(s):  
Design Procedure ◽  
Optimization Techniques ◽  
Squeeze Film ◽  
Design Parameters ◽  
Element Formulation ◽  
Rotor Systems ◽  
Transmitted Force ◽  
Squeeze Film Dampers ◽  
Speed Range ◽  
Damper Design

Optimization techniques are employed to design squeeze film dampers for minimum transmitted load to the bearing and foundation in the operational speed range. The rotor systems are modeled by finite element formulation. The maximum transmitted load in the operational speed range is the objective function that is minimized using mathematical nonlinear programming (NLP) techniques. The damper design parameters are the radius, length, and radial clearance. Stability of the equilibrium solutions are investigated in the design procedure. Design derivatives have been determined in closed form expressions without resolution of the inherently nonlinear problem. A parametric study of the transmitted force is carried out to show the influence of damper parameters on the response and to demonstrate the merits of applying optimization techniques in damper design. Two numerical examples are presented that illustrate the effectiveness of optimizing squeeze film damper designs for reducing transmitted load.

scholarly journals Dynamic Behavior of Geared Rotors

1997 ◽  
Author(s):  
T. N. Shiau ◽  
J. S. Rao ◽  
J. R. Chang ◽  
Siu-Tong Choi
Keyword(s):  
Dynamic Behavior ◽  
Chaotic Behavior ◽  
Squeeze Film ◽  
Rotor Systems ◽  
Lateral Vibrations ◽  
Squeeze Film Dampers ◽  
Torsional Excitation ◽  
Route To Chaos

This paper is concerned with the dynamic behavior of geared rotor systems supported by squeeze film dampers, wherein coupled bending torsion vibrations occur. Considering the imbalance forces and gravity, it is shown that geared rotors exhibit chaotic behavior due to non linearity of damper forces. The route to chaos in such systems is established. In geared rotor systems, it is shown that torsional excitation can induce lateral vibrations. It is shown that squeeze film dampers can suppress large amplitudes of whirl arising out of torsional excitation.

scholarly journals Squeeze-Film Damper Technology: Part 1 — Prediction of Finite Length Damper Performance

1983 ◽  
Author(s):  
J. W. Lund ◽  
A. J. Smalley ◽  
J. A. Tecza ◽  
J. F. Walton
Keyword(s):  
Finite Length ◽  
Gas Turbines ◽  
Squeeze Film ◽  
Fluid Inertia ◽  
Inertia Effects ◽  
Strongly Coupled ◽  
Squeeze Film Damper ◽  
Rotor Systems ◽  
Squeeze Film Dampers ◽  
Calculation Results

Squeeze-film dampers are commonly used in gas turbine engines and have been applied successfully in a great many new designs, and also as retrofits to older engines. Of the mechanical components in gas turbines, squeeze-film dampers are the least understood. Their behavior is nonlinear and strongly coupled to the dynamics of the rotor systems on which they are installed. The design of these dampers is still largely empirical, although they have been the subject of a large number of past investigations. To describe recent analytical and experimental work in squeeze-film damper technology, two papers are planned. This abstract outlines the first paper, Part 1, which concerns itself with squeeze-film damper analysis. This paper will describe an analysis method and boundary conditions which have been developed recently for modelling dampers, and in particular, will cover the treatment of finite length, feed and drain holes and fluid inertia effects, the latter having been shown recently to be of great importance in predicting rotor system behavior. A computer program that solves the Reynolds equation for the above conditions will be described and sample calculation results presented.

Genetic Optimization of Geometrical Parameters of High Speed Rotor

2015 ◽  
Author(s):  
Behnam Ghalamchi ◽  
Adam Kłodowski ◽  
Jussi T. Sopanen ◽  
Aki M. Mikkola
Keyword(s):  
High Speed ◽  
Turbine Rotor ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Campbell Diagram ◽  
Critical Speeds ◽  
Operation Speed ◽  
Wide Range ◽  
Speed Range

The main scope of this paper is optimization of high speed rotor systems by using Evolutionary Algorithm. The target of the optimization is finding geometrical parameters of the shaft, in such a way that the critical speeds are not occurring in the operation speed range. Rotating machines have a wide range of applications in industrial machinery and applying numerical optimization techniques helps engineers to improve the performance of rotor bearing systems. A schematic of a turbine rotor system is studied. The rotor is modeled using finite element method and Timoshenko beam elements having four degrees of freedom (DOF) per node — two translational and two rotational. Critical speeds are identified using Campbell diagram. The outcome of the simulation is looking to find the widest safe margin for operation speed range without any critical speed in Campbell diagram within the operation range. Design parameters for optimization are overhang shafts lengths and diameters. Several simulation runs with different variables shows a significant effect of these parameters in dynamic behavior of the system. Comparison of the results with the basic design of turbine rotor reveals that all constraints are satisfied.

A Chambered Porous Damper for Rotor Vibration Control: Part I—Concept Development

1993 ◽  
Vol 115 (2) ◽  
pp. 360-365 ◽  
Author(s):  
J. Tecza ◽  
J. Walton
Keyword(s):  
Concept Development ◽  
Squeeze Film ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
High Eccentricity ◽  
Wide Range ◽  
Squeeze Film Dampers ◽  
Theoretical Predictions ◽  
Damper Design ◽  
Control Part

In this paper a novel, high-load chambered porous damper design, supporting analysis, and experimental results are presented. It was demonstrated that significant damping can be generated from the viscous discharge losses of capillary tubes arranged in chambered segments with large radial clearances and that the resulting damping is predictable and fairly constant with speed and eccentricity ratio. This design avoids the nonlinearities associated with high-eccentricity operation of conventional squeeze film dampers. Controlled orbit tests with a porous chambered configuration were completed and favorably compared with theoretical predictions. The ability to accommodate high steady-state and transient imbalance conditions makes this damper well suited to a wide range of rotating machinery, including aircraft gas turbine engines.

The Control of Engine Vibration Using Squeeze Film Dampers

1983 ◽  
Vol 105 (3) ◽  
pp. 525-529 ◽  
Author(s):  
R. Holmes
Keyword(s):  
Experimental Work ◽  
Squeeze Film ◽  
Vibration Isolator ◽  
Squeeze Film Damper ◽  
Engine Vibration ◽  
Transmitted Force ◽  
Squeeze Film Dampers ◽  
Jump Phenomena ◽  
Theoretical Predictions ◽  
In Series

This paper describes the following roles of a squeeze-film damper when used in gas turbine applications as a means of reducing vibration and transmitted force due to unbalance: (a) as an element in parallel with a soft spring in a vibration isolator; and (b) as an element in series with the stiffness of the engine pedestal. The effects of cavitation on performance are elucidated, and the dangers of jump phenomena and subsynchronous response are discussed. Experimental work is described in which both roles of the squeeze-film damper are investigated and the results are compared with theoretical predictions.

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.

The Effect of Bistable Jump on the Reliability of Squeeze Film Damper

1991 ◽  
Author(s):  
Zhu Changsheng
Keyword(s):  
High Speed ◽  
Operating Time ◽  
Squeeze Film ◽  
Jump Phenomenon ◽  
Rotor Vibration ◽  
Squeeze Film Damper ◽  
Operation Speed ◽  
Squeeze Film Dampers ◽  
Speed Range ◽  
Pass Through

Abstract Based on lots of data from an experiment of a high-speed rotor supported on squeeze film dampers, this paper analyses that how the bistable jump affects the reliability of squeeze film dampers, if the rotor system has to frequently pass through the bistable oparation speed range. It is shown that the change of the rotor vibration amplitudes caused by times of passed through bistable operation speed range is more significant than that caused by steady operating time. The users must pay much attention to the bistable jump phenomenon in the successful application of squeeze film dampers.

Experiments on the Dynamic Behavior of a Supercritical Rotor

1982 ◽  
Vol 104 (2) ◽  
pp. 364-369
Author(s):  
M. Botman ◽  
M. A. Samaha
Keyword(s):  
Strain Energy ◽  
Squeeze Film ◽  
Maximum Speed ◽  
Stability Behavior ◽  
Squeeze Film Dampers ◽  
Rolling Element ◽  
Speed Range ◽  
In Series ◽  
The Stability ◽  
Desirable Effect

Tests have been performed on supercritical rotors to determine the sensitivity to unbalance and the suitability of balancing techniques. Results are presented for a rotor with an overhanging disk and supported on two rolling element bearings in series with squeeze-film dampers. The rotor has two flexural modes with high relative strain energy in the speed range up to 55,000 rpm. After completion of the balancing exercise the rotor could be run to maximum speed and was found to be stable and free from half-frequency whirl instability, depending on the oil inlet pressure of the dampers. Pressurization of the dampers and increasing the clearance of the dampers had a very desirable effect on the stability behavior and the unbalance response.

Fault Diagnosis on an Aircraft Engine Model Equipped With Self-Sensing Piezoelectric Actuators

2016 ◽  
Author(s):  
Ramakrishnan Ambur ◽  
Xiaonan Zhao ◽  
Stephan Rinderknecht
Keyword(s):  
Fault Diagnosis ◽  
Piezoelectric Materials ◽  
Piezoelectric Actuators ◽  
Aircraft Engine ◽  
Axial Direction ◽  
Squeeze Film ◽  
Sensors And Actuators ◽  
Rotor Systems ◽  
Engine Model ◽  
Squeeze Film Dampers

Piezoelectric actuators provide an active solution for vibration control in aircraft engines compared to the state-of-the-art squeeze film dampers. The property of piezoelectric materials enable them to be used as sensors and actuators simultaneously. This self-sensing property of the actuator is analyzed in this paper for its ability to detect unbalance faults, which are common in rotor systems. In this paper two different actuator configurations are studied for its ability to diagnose unbalance faults in an aircraft engine. Three parameters of unbalances such as its magnitude, its position in the circumferential and axial direction in a rotor are estimated through simulations. Finally a suitable position to achieve a better fault diagnosis is identified.

Squeeze-Film Damper Predictions for Simulation of Aircraft Engine Rotordynamics

2004 ◽  
Author(s):  
Cyril Defaye ◽  
Franck Laurant ◽  
Philippe Carpentier ◽  
Mihai Arghir ◽  
Olivier Bonneau ◽  
...  
Keyword(s):  
Reynolds Equation ◽  
Aircraft Engine ◽  
Theoretical Work ◽  
Analytical Models ◽  
Squeeze Film ◽  
Design Parameters ◽  
Aircraft Engines ◽  
Predictive Tool ◽  
Squeeze Film Dampers ◽  
Inertia Forces

On aircraft engines, a common recurring problem is excessive vibration levels generated by unbalance. With rotors mounted on usual undamped ball bearings, an amount of damping is required to limit peak amplitudes at traversed critical speeds: a solution is to introduce external damping with squeeze-film dampers. Such dampers can be added with minor modifications of the rotor system design. This paper presents experimental and theoretical work in progress focused on the analysis of squeeze film dampers (SFD) based on serial aircraft engines design. Several squeeze-film geometries were tested to measure the influence of different design parameters as the fluid clearance and the groove feeding system. Next, a damper model based on the numerical solution of the Reynolds equation is correlated with the experimental data to obtain predictive global forces. It is shown that the theoretical model is a good predictive tool if it is correctly adjusted and if temporal inertia forces are negligible. The present damper model is further compared with analytical models taken from the literature which are obviously more appropriate to be used in whole engine rotordynamic analysis. The limits of the models are then underlined by comparisons with experimental results.

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