Effects of Rub-Impact on Vibration Response of a Dual-Rotor System-Theoretical and Experimental Investigation

2019 ◽  
Vol 44 (3) ◽  
pp. 299-311 ◽  
Author(s):  
N. Wang ◽  
D. Jiang ◽  
H. Xu
Keyword(s):  
Experimental Investigation ◽  
Rotor System ◽  
Vibration Response

scholarly journals EFFECT OF FRICTION ON VIBRATIONAL CHARACTERISTICS OF ROTOR SYSTEM DURING ROTOR-STATOR INTERACTION

2020 ◽  
pp. 22-31
Author(s):  
Anton Kurakin ◽  
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Friction Coefficient ◽  
Rotor System ◽  
Aluminum Bronze ◽  
Rotor Systems ◽  
Vibrational Characteristics ◽  
Rotor Stator Interaction ◽  
Intermediate Value ◽  
Impact Motion

Systems operation which include rotating elements in certain cases is associated with occurrence of contact between the rotating parts (rotor) and the stationary parts (stator). There were cases then rotor-stator interaction led to damage or to complete unit destruction. For this reason, rotor-stator interaction is one of the main problem of rotor systems exploitation. The main aim of the work is to gather detail data about effect of friction on vibrational characteristics of rotor system during rotor-stator interaction. In this article the experimental investigation method and experimental investigation of dynamic behavior of rotor during rotor-stator interaction is presented. The analysis of experimental data obtained during interaction between steel rotor and stator made of aluminum, bronze and PTFE is presented. All results with rotor-stator contact and without were compared by using Campbell diagrams, orbits and frequency responses. Analysis of experimental data shows that friction has strong effect on vibrational characteristics of rotor system during rotor-stator interaction. According to friction ratio three kinds of vibrational characteristics of rotor system are distinguished: forward slipping if friction coefficient is small, backward rolling if friction coefficient is big, vibratory impact motion if friction coefficient has intermediate value. Created experimental method and gathered data about rotor dynamics during rotor-stator contact can be used for verification and tuning of mathematical models.

Experimental Investigation into the Vibration Response of an Aero-Engine Rotor-Damper Assembly

1994 ◽  
Vol 208 (1) ◽  
pp. 52-66 ◽  
Author(s):  
M C Levesley ◽  
R Holmes
Keyword(s):  
Experimental Investigation ◽  
Harmonic Balance ◽  
Vibration Response ◽  
Linear Vibration ◽  
Film Rupture ◽  
Supply Pressure ◽  
Balance Principle ◽  
Aero Engine ◽  
Rupture Pressure ◽  
Engine Rotor

This paper presents experimental results on the non-linear vibration response of a rotating assembly comprising a rotor, flexible bearing housing and oil film damper. For the latter, due consideration is given to the effects of oil-supply pressure, film-rupture pressure and end sealing. The results are compared with predictions based on the Harmonic Balance principle described in a complementary paper (1).

scholarly journals Research on Automatic Balance Control of Active Magnetic Bearing-Rigid Rotor System

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yang Liu ◽  
Shuaishuai Ming ◽  
Siyao Zhao ◽  
Jiyuan Han ◽  
Yaxin Ma
Keyword(s):  
Vibration Control ◽  
Rotational Speed ◽  
Notch Filter ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Vibration Response ◽  
Active Magnetic Bearing ◽  
Rigid Rotor ◽  
Phase Compensation ◽  
Synchronous Control

In this paper, in order to solve the problem of unbalance vibration of rigid rotor system supported by the active magnetic bearing (AMB), automatic balancing method is applied to suppress the unbalance vibration of the rotor system. Firstly, considering the dynamic and static imbalance of the rotor, the detailed dynamic equations of the AMB-rigid rotor system are established according to Newton’s second law. Then, in order to rotate the rotor around the inertia axis, the notch filter with phase compensation is used to eliminate the synchronous control current. Finally, the variable-step fourth-order Runge–Kutta iteration method is used to solve the unbalanced vibration response of the rotor system in MATLAB simulation. The effects of the rotational speed and phase compensation angle on the unbalanced vibration control are analysed in detail. It is found that the synchronous control currents would increase rapidly with the increase of rotational speed if the unbalance vibration cannot be controlled. When the notch filter with phase shift is used to balance the rotor system automatically, the control current is reduced significantly. It avoids the saturation of the power amplifier and reduces the vibration response of the rotor system. The rotor system can be stabilized over the entire operating speed range by adjusting the compensation phase of the notch filter. The method in the paper is easy to implement, and the research result can provide theoretical support for the unbalance vibration control of AMB-rotor systems.

An Experimental Investigation on the Response of a Flexible Rotor Mounted in Pressure Dam Bearings

1980 ◽  
Vol 102 (4) ◽  
pp. 842-850 ◽  
Author(s):  
R. D. Flack ◽  
M. E. Leader ◽  
E. J. Gunter
Keyword(s):  
Experimental Investigation ◽  
Rotor System ◽  
Flexible Rotor ◽  
The Stability

The response of a flexible rotor mounted in six bearing sets has been experimentally determined. One set of axial groove bearings and five sets of pressure dam bearings were tested. Conventional synchronous tracking was used in the analysis and other techniques utilizing an FFT analyzer were developed. The stability of the system was seen to strongly depend on the design of the step bearings. The dam bearings were also noted to lock into subsynchronous whip during deceleration after the system went unstable. The response of the system with varying degrees of unbalance is also analyzed and several structural resonances of the rotor system are discussed.

Experimental Investigations of Single and Multi-Fault in Rotor System

2014 ◽  
Vol 541-542 ◽  
pp. 628-634
Author(s):  
S.P. Mogal ◽  
D.I. Lalwani
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Real Life ◽  
Rotor System ◽  
Vibration Response ◽  
Experimental Investigations ◽  
Multiple Faults ◽  
Single Fault ◽  
Vibration Behavior ◽  
Combined Action

Many researchers dealt with single fault but in real life situations, combined action of two or more single faults are usually present. Multi-faults (two and three combinations) were studied by few researchers. Researchers have mostly studied the vibration behavior of a rotor with misalignment, unbalance and rub separately. This paper presents one such case, where multiple faults are considered together in a rotor system, i.e. misalignment, unbalance and rub. The objective of this paper is to experimentally investigate the vibration response of combined of three faults misalignment, unbalance and rub using Fast Fourier Transform (FFT). FFT spectrum of combination of three faults misalignment, unbalance and rub show 1 X and 2 X are predominant and many sub harmonics are generated.1X peak represent unbalance, 2X peak represents misalignment and sub harmonics shows rub fault.

Influence Characteristics of Fluid Film Bearing’s Displacement-Load on Rotating Vibration of Rotor System

2015 ◽  
Vol 727-728 ◽  
pp. 567-571
Author(s):  
Xi Chen Lin ◽  
Rui Ping Zhou ◽  
Neng Qi Xiao
Keyword(s):  
Mathematical Model ◽  
Numerical Integration ◽  
Dynamic Characteristics ◽  
Load Distribution ◽  
High Load ◽  
Rotor System ◽  
Vibration Response ◽  
Fluid Film ◽  
Load Carrying

In high load-carrying bearing-rotor system, bearings’ places usually change for load distribution or in continual work. It influences the system’s stability, and brings out different vibration response in rotor system. This article puts forward mathematical model of bearing’s stiffness under load which is calculated from bearing displacement. Then through numerical integration it studies system’s rotating vibration with different bearing settings. The results of the analysis show that bearing displacement has a great effect on dynamic characteristics of the bearing-rotor system.

On LMI-Based Optimization of Vibration and Stability in Rotor System Design

2005 ◽  
Author(s):  
Matthew O. T. Cole ◽  
Theeraphong Wongratanaphisan ◽  
Patrick S. Keogh
Keyword(s):  
System Design ◽  
Rotor System ◽  
Vibration Response ◽  
Linear Matrix ◽  
Matrix Inequalities ◽  
Axial Distribution ◽  
Worst Case ◽  
The Matrix ◽  
Gyroscopic Effects ◽  
Parameter Constraints

This paper considers optimization of rotor system design using stability and vibration response criteria. The initial premise of the study is that the effect of certain design changes can be parameterized in a system dynamic model through their influence on the system matrices obtained by finite element modeling. A suitable vibration response measure is derived by considering an unknown axial distribution of unbalance components having bounded magnitude. It is shown that the worst-case unbalance response is given by an absolute row-sum norm of the system frequency response matrix. The minimization of this norm is treated through the formulation of a set of linear matrix inequalities (LMIs) that can also incorporate design parameter constraints and stability criteria. The formulation can also be extended to cover uncertain or time-varying system dynamics arising, for example, due to speed-dependent bearing coefficients or gyroscopic effects. Numerical solution of the matrix inequalities is tackled using an iterative method that involves standard convex optimization routines. The method is applied in a case study that considers the optimal selection of bearing support stiffness and damping levels to minimize the worst-case vibration of a flexible rotor over a finite speed range. The main restriction in the application of the method is found to be the slow convergence of the numerical routines that occurs with high-order models and/or high problem complexity.

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