Since the current thickness of the gas film between the slider and the disk in Hard Disk Drive is already only one order of magnitude larger than the diameter of gas molecules, the nanoscale effect cannot be neglected any longer. In this paper a nanoscale effect function, $Np$ is proposed by investigating the unidirectional flow of the rarefied gas between two parallel plates, and four kinds of formerly and currently employed lubrication models are modified. The calculated results using the modified Reynolds equations indicate that the nanoscale effect weaken the rarefaction effect to some extent for ultra-thin gas film lubrication.

1.
Shen
,
X. J.
, and
Bogy
,
D. B.
,
2003
, “
Particle Flow and Contamination in Slider Air Bearings for Hard Disk Drives
,”
ASME J. Tribol.
,
125
(
2
), pp.
358
363
.
2.
Zhang
,
B.
, and
Nakajima
,
A.
,
2003
, “
Possibility of Surface Force Effect in Slider Air Bearings of 100 Gbit/in2 Hard Disks
,”
Tribol. Int.
,
36
, pp.
291
296
.
3.
Zhou
,
L.
,
Kato
,
K.
, et al.
,
2003
, “
The Effect of Slider Surface Texture on Flyability and Lubricant Migration Under Near Contact Conditions
,”
Tribol. Int.
,
36
, pp.
269
277
.
4.
Burgdorfer
,
A.
,
1959
, “
The Influence of the Molecular Mean Free Path on the Performance of Hydrodynamic Gas Lubricated Bearings
,”
ASME J. Basic Eng.
,
81
(
3
), pp.
94
100
.
5.
Kennard, E. H., 1938, Kinetic Theory of Gases, McGraw-Hill.
6.
Hisa
,
Y. T.
, and
Domoto
,
G. A.
,
1983
, “
An Experimental Investigation of Molecular Rarefaction Effects in Gas Lubricated bearings at Ultra-Low Clearances
,”
ASME J. Lubr. Technol.
,
105
, pp.
120
130
.
7.
Mitsuya
,
Y.
,
1993
, “
Modified Reynolds Equation for Ultra-Thin Film Gas Lubrication Using 1.5-Order Slip-Flow Model and Considering Surface Accommodation Coefficient
,”
ASME J. Tribol.
,
115
, pp.
289
294
.
8.
Odaka
,
T.
,
Tanaka
,
K.
,
Takeuchi
,
Y.
, and
Saitoh
,
Y.
,
1986
, “
Analysis of Lubricated Bearing Performance With Very Low Clearances
,”
Trans. Jpn. Soc. Mech. Eng., Ser. C
,
52
, No.
475-C
, pp.
1047
1056
.
9.
Gans
,
R. F.
,
1985
, “
Lubrication Theory at Arbitrary Knudsen Number
,”
ASME J. Tribol.
,
107
, pp.
431
433
.
10.
Fukui
,
S.
, and
Kaneko
,
R.
,
1988
, “
Analysis of Ultra-Thin Gas Film Lubrication Based on Linearized Boltzmann Equation: First Report-Derivation of a Generalized Lubrication Equation Including Thermal Creep Flow
,”
ASME J. Tribol.
,
110
, pp.
253
262
.
11.
Fukui
,
S.
, and
Kaneko
,
R.
,
1990
, “
A Database for Interpolation of Poiseuille Flow Rates for High Knudsen Number Lubrication Problems
,”
ASME J. Tribol.
,
112
, pp.
78
83
.
12.
Bird, G. A., 1976, Molecular Gas Dynamics, Oxford University Press.
13.
Chapman, S., and Cowling, T. G., 1939, The Mathematical Theory of Nonuniform Gases, Cambridge University Press.
14.
Abramowita, M., and Stegun, I. A., 1969, Handbook of Mathematical Functions, Dover.
15.
Cercignani
,
C.
, and
Pagani
,
D. A.
,
1966
, “
Variational Approach to Boundary-Value Problems in Kinetic Theory
,”
Phys. Fluids
,
9
(
6
), pp.
1167
1173
.
You do not currently have access to this content.