Theoretical investigation on porous tilting pad bearings considering tilting pad motion and porous material restriction

Feng, Kai; Wu, Yihua; Liu, Wanhui; Zhao, Xiaohan; Li, Wenjun

doi:10.1016/j.precisioneng.2018.02.010

Cited by 23 publications

(7 citation statements)

References 20 publications

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“…where the pressure values at each pore are stored in the vector P. Q represents the flow rate at each pore of the pore network, and their summation is equal to zero, according to equation (8). The conductance matrix G is a sparse, symmetric matrix with non-diagonal elements expressed by the cylindrical hydraulic conductance.…”

Section: Pore Networkmentioning

confidence: 99%

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Study on the linkages between microstructure and permeability of porous media using pore network and BP neural network

Liu

Wang

et al. 2022

Mater. Res. Express

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In applying porous media air bearings (PMABs), designing the pore microstructure of porous media to obtain the desired permeability is challenging. The key parameters in this design are to map the pore microstructure characteristics to permeability and adapt to manufacturing process with the characteristics. For this purpose, a framework is proposed to characterize pore microstructure with morphology descriptor and predict permeability. 3D digital images of porous media are obtained using X-ray micro-computed tomography and various image construction techniques. The complex pore microstructure of porous media is represented with a pore network. Permeability is calculated based on the pore network. Sixteen pore microstructure morphology descriptors are initially calculated to characterize pore microstructure. A back-propagation neural network (BPNN) is built to learn the correlation between morphology descriptors and permeability. Pearson correlation coefficient (PCC) and feature importance scores of morphology descriptors are obtained based on the dataset and trained BPNN. The results demonstrate that the prediction performance of BPNN is excellent. The following six morphology descriptors (porosity, coordination number, average pore diameter, average throat diameter, average pore throat ratio, average throat length) are reserved to characterize pore microstructure. Finally, two types of pore microstructure are designed with the help of knowledge obtained by this research.

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Section: Pore Networkmentioning

confidence: 99%

“…Many studies have been done with the guidance of PMABs by the reference of papers [4][5][6][7][8][9]. However, these works mainly focus on the macro-performance such as capacity, stiffness, which cannot provide sufficient knowledge for the design of the pore microstructure of porous media.…”

Section: Introductionmentioning

confidence: 99%

Study on the linkages between microstructure and permeability of porous media using pore network and BP neural network

Liu

Wang

et al. 2022

Mater. Res. Express

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“…Predictions of the rotor-bearing system response to imbalance produced accurate critical speeds but overvalued the damping ratio by 30% compared to the experimental data. Based on the study, 6 Feng et al 11 developed a numerical model for HPTPBs considering the structural effect of the tilting pad and porous restrictor. The static performance was predicted using Darcy's equation coupling solved with the motion equation of the tilting pads, and the dynamic characteristics were obtained from the steady-state perturbation.…”

Section: Introductionmentioning

confidence: 99%

A novel transient computational fluid dynamics-fluid–structure interaction model for the pad adaptive motion and rotordynamic coefficients of hybrid porous tilting pad bearings

Xia,

Jin,

Song

et al. 2024

Proceedings of the Institution of Mechanical Engineers, Part J:

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Hybrid porous tilting pad bearings with the advantages of gas porous bearings and tilting pad bearings exhibited excellent rotor-supporting performance with high accuracy and stability. Under hybrid lubrication, the transient adaptive motion of the tilting pads was important for the rotordynamic characteristics. A novel fluid–structure interaction model of hybrid porous tilting pad bearings was developed to investigate the transient hydro forces and the pad's adaptive motion. The rotordynamic coefficients of the hybrid porous tilting pad bearings were identified using the rotor harmonic trajectory. The computational fluid dynamics-fluid–structure interaction model was validated with the experimental data. The effects of eccentricity ratios, rotor speeds, supply pressures, pivot radial stiffnesses, and dampings on the pad adaptive motion and the rotordynamic coefficients were evaluated. The pad self-adaption motions significantly influenced the supporting and vibration-absorbing characteristics of hybrid porous tilting pad bearings.

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“…The restrictor that controls the flow velocity is the key component in the air bearing, but a classic orifice-type restrictor limits its stability and precision due to a gas hammer effect [4]. Porous restriction can achieve a more uniform pressure distribution on the bearing's surface, and as such is receiving more and more attention [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Rational Design and Porosity of Porous Alumina Ceramic Membrane for Air Bearing

Xiao

et al. 2021

Membranes

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Air bearing has been widely applied in ultra-precision machine tools, aerospace and other fields. The restrictor of the porous material is the key component in air bearings, but its performance is limited by the machining accuracy. A combination of optimization design and material modification of the porous alumina ceramic membrane is proposed to improve performance within an air bearing. Porous alumina ceramics were prepared by adding a pore-forming agent and performing solid-phase sintering at 1600 °C for 3 h, using 95-Al2O3 as raw material and polystyrene microspheres with different particle sizes as the pore-forming agent. With 20 wt.% of PS50, the optimum porous alumina ceramic membranes achieved a density of 3.2 g/cm3, a porosity of 11.8% and a bending strength of 150.4 MPa. Then, the sintered samples were processed into restrictors with a diameter of 40 mm and a thickness of 5 mm. After the restrictors were bonded to aluminum shells for the air bearing, both experimental and simulation work was carried out to verify the designed air bearing. Simulation results showed that the load capacity increased from 94 N to 523 N when the porosity increased from 5% to 25% at a fixed gas supply pressure of 0.5 MPa and a fixed gas film thickness of 25 μm. When the gas film thickness and porosity were fixed at 100 μm and 11.8%, respectively, the load capacity increased from 8.6 N to 40.8 N with the gas supply pressure having been increased from 0.1 MPa to 0.5 MPa. Both experimental and simulation results successfully demonstrated the stability and effectiveness of the proposed method. The porosity is an important factor for improving the performance of an air bearing, and it can be optimized to enhance the bearing’s stability and load capacity.

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Theoretical investigation on porous tilting pad bearings considering tilting pad motion and porous material restriction

Cited by 23 publications

References 20 publications

Study on the linkages between microstructure and permeability of porous media using pore network and BP neural network

Study on the linkages between microstructure and permeability of porous media using pore network and BP neural network

A novel transient computational fluid dynamics-fluid–structure interaction model for the pad adaptive motion and rotordynamic coefficients of hybrid porous tilting pad bearings

Rational Design and Porosity of Porous Alumina Ceramic Membrane for Air Bearing

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