The Influence of Ring-Speed Ratio Dynamic Change on Nonlinear Vibration Response of High-Speed Turbocharger Rotor System

Guangfu Bin,Liang Zhang,Feng Yang,Anhua Chen,Lei Hou

doi:10.1155/2021/9649232

Guangfu Bin, Liang Zhang + Show 3 more

Open Access

https://doi.org/10.1155/2021/9649232

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Abstract

The ring-speed ratio is a comprehensive dynamic index of floating ring bearing structure and operating parameters, which directly affects the dynamic behavior of the turbocharger rotor system. The cross stiffness of ring-speed ratio and floating ring bearing and the work of oil film force are analyzed. The influence of dynamic ring-speed ratio change on the vibration response of floating ring bearing was studied. The finite element model of the rotor-floating ring bearing system is constructed; its model parameters are verified through the measured critical rotor speed. Newmark integral method is used to analyze the nonlinear transient response. The results show that when the ring-speed ratio is between 0.18 and 0.24, the rotor is in a good operating state; when it increases from 0.24 to 0.36, the rotor vibration is dominated by frequency division, and the system will be less stable. The square of the ring-speed ratio is inversely proportional to the rotational speed of the journal where the subfrequency vibration occurs. It helps to know the nonlinear vibration by judging the journal speed when the rotor vibration occurs in subfrequency. The conclusion provides a reference for the mechanical dynamics design and intelligent management and maintenance of this kind of turbine rotors.

Highlights

Ring-speed ratio is the ratio of floating ring speed to rotor journal speed, which determines the stability and reliability of the rotor bearing system to a large extent, and its variation range is generally between 0.10 and 0.35 [1]. erefore, it has become a key problem to be solved in high-speed rotor dynamics design to master the influence law of ring speed ratio on the vibration of the high-speed light-loaded turbocharger rotor system
[16] analyzed the dynamic behavior of the rotor-bearing system with internal damping composite materials under the action of temperature field, and the results showed that the increase of temperature field would generate tangential force for the damping of the rotor system, affecting the stability of the rotor system
Most of the researchers only consider the influence of fixed ring speed ratio on the nonlinear vibration of rotor and the stability of rotor system, the speed range, and the speed fluctuation of the turbocharger rotor and rarely consider the influence of the dynamic change of the ring-speed ratio on the stability of the turbocharger rotor system. erefore, this paper systematically studies the influence of dynamically changing ring-speed ratio on the stability and nonlinear vibration characteristics of the high-speed light-load turbocharger rotor system

Summary

Introduction

Ring-speed ratio is the ratio of floating ring speed to rotor journal speed, which determines the stability and reliability of the rotor bearing system to a large extent, and its variation range is generally between 0.10 and 0.35 [1]. erefore, it has become a key problem to be solved in high-speed rotor dynamics design to master the influence law of ring speed ratio on the vibration of the high-speed light-loaded turbocharger rotor system. Erefore, this paper systematically studies the influence of dynamically changing ring-speed ratio on the stability and nonlinear vibration characteristics of the high-speed light-load turbocharger rotor system. Wo πaobo sin φ􏼐koxy − koyx􏼑 − πcωj􏼐coxxa2o + coyyb2o􏼑 − πcωjaobo cos φ􏼐coxy + coyx􏼑 In this equation, πabsinφ represents the area of the vortex trajectory of the inner and outer oil film, c is the damping coefficient, and φ is the rotation angle, a is the major axis of the ellipse, and b is the minor axis of the ellipse. According to the above analysis, it can be concluded that the ring-speed ratio mainly changes the inner and outer oil film pressure of the floating ring bearing and the cross stiffness of the rotor system, which affects the response of the turbocharger floating ring bearing and rotor system under nonlinear vibration

FEM Modeling and Its Experimental Analysis

Harmonic Response Analysis of the Turbocharger Rotor System

X 196000

Conclusions