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CLC number: TH117.2

On-line Access: 2009-11-30

Received: 2009-03-10

Revision Accepted: 2009-07-06

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Journal of Zhejiang University SCIENCE A 2010 Vol.11 No.1 P.43-49

10.1631/jzus.A0900141


Effects of rarefaction on the characteristics of micro gas journal bearings


Author(s):  Hai-jun ZHANG, Chang-sheng ZHU, Ming TANG

Affiliation(s):  College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China; more

Corresponding email(s):   zhjzszs_537@hotmail.com, cszhu@hotmail.com

Key Words:  Reference Knudsen number, Rarefaction effect, Reynolds equation, Finite difference method (FDM)


Hai-jun ZHANG, Chang-sheng ZHU, Ming TANG. Effects of rarefaction on the characteristics of micro gas journal bearings[J]. Journal of Zhejiang University Science A, 2010, 11(1): 43-49.

@article{title="Effects of rarefaction on the characteristics of micro gas journal bearings",
author="Hai-jun ZHANG, Chang-sheng ZHU, Ming TANG",
journal="Journal of Zhejiang University Science A",
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pages="43-49",
year="2010",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.A0900141"
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%0 Journal Article
%T Effects of rarefaction on the characteristics of micro gas journal bearings
%A Hai-jun ZHANG
%A Chang-sheng ZHU
%A Ming TANG
%J Journal of Zhejiang University SCIENCE A
%V 11
%N 1
%P 43-49
%@ 1673-565X
%D 2010
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.A0900141

TY - JOUR
T1 - Effects of rarefaction on the characteristics of micro gas journal bearings
A1 - Hai-jun ZHANG
A1 - Chang-sheng ZHU
A1 - Ming TANG
J0 - Journal of Zhejiang University Science A
VL - 11
IS - 1
SP - 43
EP - 49
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Y1 - 2010
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.A0900141


Abstract: 
Given the definition of the reference Knudsen number for micro gas journal bearings, the range in the number is related to the viscosity of air at different temperatures. A modified reynolds equation for micro gas journal bearings based on Burgdorfer’s first-order slip boundary condition is proposed that takes into account the gas rarefaction effect. The finite difference method (FDM) is adopted to solve the modified reynolds equation to obtain the pressure profiles, load capacities and attitude angles for micro gas journal bearings at different reference Knudsen numbers, bearing numbers and journal eccentricity ratios. Numerical analysis shows that pressure profiles and non-dimensional load capacities decrease markedly as gas rarefaction increases. Attitude angles change conversely, and when the eccentricity ratio is less than 0.6, the attitude angles rise slightly and the influence of the reference Knudsen number is not marked. In addition, the effect of gas rarefaction on the non-dimensional load capacity and attitude angle decreases with smaller bearing numbers.

Darkslateblue:Affiliate; Royal Blue:Author; Turquoise:Article

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