Nonlinear dynamic behaviors of a rod fastening rotor supported by fixed–tilting pad journal bearings

2014 ◽  
Vol 69 ◽  
pp. 129-150 ◽  
Author(s):  
Di Hei ◽  
Yanjun Lu ◽  
Yongfang Zhang ◽  
Zunyou Lu ◽  
Parag Gupta ◽  
...  
Keyword(s):  
Nonlinear Dynamic ◽  
Journal Bearings ◽  
Dynamic Behaviors ◽  
Tilting Pad ◽  
Rod Fastening Rotor ◽  
Tilting Pad Journal Bearings

Nonlinear Dynamic Behaviors of an Imbalance Rotor Supported on Fixed-Tilting Pad Journal Bearings

2011 ◽  
Vol 291-294 ◽  
pp. 1941-1951
Author(s):  
Xiao Bing Qi ◽  
Lei Feng ◽  
Yong Fang Zhang ◽  
Yan Jun Lu
Keyword(s):  
Pressure Distribution ◽  
Reynolds Equation ◽  
Axial Direction ◽  
Journal Bearings ◽  
Nonlinear Phenomena ◽  
Dynamic Behaviors ◽  
Oil Film ◽  
Tilting Pad ◽  
Field Dynamic ◽  
Tilting Pad Journal Bearings

Based on the unsteady Reynolds equation with Reynolds boundary, two-dimensional (2D) Reynolds equation is transformed into one-dimensional (1D) by taking the assumption of parabolic pressure distribution in axial direction in oil film field. Finite difference method was employed to solve 1D Reynolds equation, and the approximate pressure distribution was obtained in oil film field. Dynamic behaviors of a flexible rotor system with fixed-tilting pad journal bearings support were analyzed while the inertia of the pads was taken into consideration in the model. Imbalance responses of a symmetrical rotor-combination journal bearings (fixed-tilting pad journal bearings) system were investigated using Poincaré map and self-adaptive Runge-Kutta method. Numerical results reveal rich and complex nonlinear phenomena, such as periodic, quasi-periodic motion, etc.

Prediction of nonlinear dynamic coefficients of tilting-pad journal bearings with pad perturbation

2021 ◽  
pp. 135065012110548
Author(s):  
Mohammad Hojjati ◽  
Seyed Younes Farzanmehr ◽  
H. M. Navaz ◽  
Hassan Haddadpour
Keyword(s):  
Partial Derivative ◽  
Nonlinear Dynamic ◽  
Perturbation Technique ◽  
Journal Bearings ◽  
Eccentricity Ratio ◽  
Linear Dynamic ◽  
Dynamic Coefficients ◽  
Tilting Pad ◽  
Derivative Method ◽  
Tilting Pad Journal Bearings

In this paper, a modified partial derivative method is developed to predict the linear and nonlinear dynamic coefficients of tilting-pad journal bearings with journal and pad perturbation. To this end, Reynolds equation and its boundary conditions along with equilibrium equations of the pad are used. Finite difference, partial derivative method, and perturbation technique have been employed simultaneously for solving these equations. The accuracy of the results is investigated by comparing the linear dynamic coefficients of three types of tilting-pad journal bearings with those published the literature. It is shown that the nonlinear dynamic coefficients depend on Sommerfeld number, eccentricity ratio, and length to diameter ratio. Similar to the case of linear dynamic coefficients of TPJB, it is observed that the eccentricity ratio effects on nonlinear dynamic coefficients are more notable when the eccentricity ratio is higher than 0.8 or less than 0.2.

Journal Vibration: Influence of Compliant Bearing Design

2012 ◽  
Author(s):  
Matthew Cha ◽  
Sergei Glavatskih
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Dynamic Behaviour ◽  
Journal Bearings ◽  
Design Parameters ◽  
Radial Clearance ◽  
White Metal ◽  
Tilting Pad ◽  
Bearing Design ◽  
Tilting Pad Journal Bearings

In this paper, the nonlinear dynamic behaviour of vertical and horizontal rotors in compliant tilting pad journal bearings has been investigated. White metal and compliant bearings with line pivot pads are compared. The dynamic response of four pad bearings with different preload factors is studied. The effect of viscoelasticity is also considered in comparison with purely elastic compliant and white metal liners. The influence of radial clearance and pad offset is analysed. It is shown how pad design parameters such as preload factor, pivot offset, viscoelasticity of the liner, and radial clearance can be selected to control the size of the journal orbit in compliant bearings.

A new dynamic mesh algorithm for studying the 3D transient flow field of tilting pad journal bearings

2016 ◽  
Vol 230 (12) ◽  
pp. 1470-1482 ◽  
Author(s):  
Mengxuan Li ◽  
Chaohua Gu ◽  
Xiaohong Pan ◽  
Shuiying Zheng ◽  
Qiang Li
Keyword(s):  
Flow Field ◽  
Equilibrium Position ◽  
Transient Flow ◽  
Journal Bearings ◽  
Dynamic Mesh ◽  
Static Equilibrium ◽  
Time Step ◽  
Tilting Pad ◽  
Grid Nodes ◽  
Tilting Pad Journal Bearings

A new dynamic mesh algorithm is developed in this paper to realize the three-dimensional (3D) computational fluid dynamics (CFD) method for studying the small clearance transient flow field of tilting pad journal bearings (TPJBs). It is based on a structured grid, ensuring that the total number and the topology relationship of the grid nodes remain unchanged during the dynamic mesh updating process. The displacements of the grid nodes can be precisely recalculated at every time step. The updated mesh maintains high quality and is suitable for transient calculation of large journal displacement in FLUENT. The calculation results, such as the static equilibrium position and the dynamic characteristic coefficients, are consistent with the two-dimensional (2D) solution of the Reynolds equation. Furthermore, in the process of transient analysis, under conditions in which the journal is away from the static equilibrium position, evident differences appear between linearized and transient oil film forces, indicating that the nonlinear transient calculation is more suitable for studying the rotor-bearing system.

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