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1

Analysis of high-speed angular ball bearing lubrication based on bi-directional fluid-solid coupling

Jiao Bowen, Bian Qiang, Wang Xinghong, Chunjiang Zhao, Chen Ming, Zhang Xiangyun

Archive of Mechanical Engineering

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2023

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LXX, nr 4

531--551

EN

The lubrication of angular contact ball bearings under high-speed motion con- ditions is particularly important to the working performance of rolling bearings. Combining the contact characteristics of fluid domain and solid domain, a lubrication calculation model for angular contact ball bearings is established based on the RNG 𝑘-𝜀 method. The pressure and velocity characteristics of the bearing basin under the conditions of rotational speed, number of balls and lubricant parameters are analyzed, and the lubrication conditions and dynamics of the angular contact ball bearings under different working conditions are obtained. The results show that the lubricant film pressure will rise with increasing speed and viscosity of the lubricant. The number of balls affects the pressure and velocity distribution of the flow field inside the bearing but has a small effect on the values of the characteristic parameters of the bearing flow field. The established CFD model provides a new approach to study the effect of fluid flow on bearing performance in angular contact ball bearings.

2

Free vibrations of Kirchhoff plates considering plate variable thickness and interaction with water including water boundaries

Lenartowicz Agnieszka, Guminiak Michał, Przychodzki Maciej

Vibrations in Physical Systems

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2021

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Vol. 32, nr 2

art. no. 2021208

EN

The natural vibrations of thin (Kirchhoff-Love) plates with constant and variable thickness and interaction with water are considered in the paper. The influence of the water free surface on natural frequencies of the coupled water-plate system is analysed too. The Finite Element Method (FEM) and the Finite Difference Method (FDM) are used to describe structural deformation and the Boundary Element Method (BEM) is applied to describe the dynamic interaction of water on a plate surface. The plate inertia forces are expressed by diagonal or consistent mass matrix. The water inertia forces are described by fully-populated mass matrix which is obtained directly from the theory of double layer potential.

3

Numerical investigation of the basilar membrane vibration induced by the unsteady fluid flow in the human inner ear

Wahl Philipp, Ziegler Pascal, Eberhard Peter

Archive of Mechanical Engineering

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2020

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LXVII, nr 4

381--414

EN

For a deeper understanding of the inner ear dynamics, a Finite-Element model of the human cochlea is developed. To describe the unsteady, viscous creeping flow of the liquid, a pressure-displacement-based Finite-Element formulation is used. This allows one to efficiently compute the basilar membrane vibrations resulting from the fluid-structure interaction leading to hearing nerve stimulation. The results show the formation of a traveling wave on the basilar membrane propagating with decreasing velocity towards the peaking at a frequency dependent position. This tonotopic behavior allows the brain to distinguish between sounds of different frequencies. Additionally, not only the middle ear, but also the transfer behavior of the cochlea contributes to the frequency dependence of the auditory threshold. Furthermore, the fluid velocity and pressure fields show the effect of viscous damping forces and allow us to deeper understand the formation of the pressure difference, responsible to excite the basilar membrane.