Performance improvement of foil air journal bearing employing micro-pocket and textures on top compliant surface

2021 ◽  
Author(s):  
Pranabesh Ganai ◽  
Raj K Pandey ◽  
Jayanta Kumar Dutt
Keyword(s):  
Performance Improvement ◽  
Journal Bearing ◽  
Compliant Surface

Application of Foil Bearings to Turbomachinery Including Vertical Operation

2002 ◽  
Vol 124 (4) ◽  
pp. 1032-1041 ◽  
Author(s):  
J. F. Walton ◽  
H. Hesmat
Keyword(s):  
Journal Bearing ◽  
Wide Spectrum ◽  
Turbine Engines ◽  
Vibrational Amplitude ◽  
Gas Turbine Engines ◽  
Foil Bearings ◽  
New Class ◽  
Compliant Surface ◽  
Actual Equipment ◽  
Bearing Design

A review is made of the function of compliant surface bearings in serving the needs of modern turbomachinery. This service extends over a wide spectrum of severe operational and environmental conditions such as extreme low and high temperatures, speeds over 100,000 rpm, and the use of cryogenics as lubricants. The importance of using appropriate simulators that duplicate the actual equipment in evaluating the application of compliant bearings is demonstrated via two specific examples; one, a simulator to evaluate bearings for an air cycle machine and another for an advanced cryogenic device. In view of the known difficulties in using hydrodynamic bearings in vertical machines a new preloaded compliant journal bearing design is offered which performs as well with a vertically mounted shaft as it does in horizontal operation. In terms of the location of the first two rigid-body criticals, the test data show the compliant bearing’s vertical operation to be at most 15 percent lower than for the horizontal case, whereas the maximum vibrational amplitude stayed the same for both modes of operation. This new class of hydrodynamic compliant surface journal bearings now makes possible development of oil-free machines capable of all attitude operation, such as aircraft gas turbine engines undergoing severe pitch maneuvers or machines that must be operated vertically due to space constraints.

scholarly journals Application of Foil Bearings to Turbomachinery Including Vertical Operation

1999 ◽  
Author(s):  
James F. Walton ◽  
Hooshang Heshmat
Keyword(s):  
Journal Bearing ◽  
Wide Spectrum ◽  
Turbine Engines ◽  
Vibrational Amplitude ◽  
Gas Turbine Engines ◽  
Foil Bearings ◽  
New Class ◽  
Compliant Surface ◽  
Actual Equipment ◽  
Bearing Design

A review is made of the function of compliant surface bearings in serving the needs of modern turbomachinery. This service extends over a wide spectrum of severe operational and environmental conditions such as extreme low and high temperatures, speeds over 100,000 rpm and the use of cryogenics as lubricants. The importance of using appropriate simulators that duplicate the actual equipment in evaluating the application of compliant bearings is demonstrated via two specific examples; one, a simulator to evaluate bearings for an air cycle machine and another for an advanced cryogenic device. In view of the known difficulties in using hydrodynamic bearings in vertical machines a new preloaded compliant journal bearing design is offered which performs as well with a vertically mounted shaft as it does in horizontal operation. In terms of the location of the first two rigid body criticals the test data show the compliant bearing’s vertical operation to be at most 15% lower than for the horizontal case whereas the maximum vibrational amplitude stayed the same for both modes of operation. This new class of hydrodynamic compliant surface journal bearings now makes possible development of oil-free machines capable of all attitude operation such as aircraft gas turbine engines undergoing severe pitch maneuvers or machines that must be operated vertically due to space constraints.

Elastomer Inertia Effects in Compliant Surface Bearings

1973 ◽  
Vol 95 (3) ◽  
pp. 372-380 ◽  
Author(s):  
J. Pirvics ◽  
V. Castelli
Keyword(s):  
Steady State ◽  
Pressure Distribution ◽  
Journal Bearing ◽  
Analytical Techniques ◽  
Operating Conditions ◽  
Infinite Length ◽  
Inertial Effects ◽  
Inertia Effects ◽  
Compliant Surface ◽  
Bearing System

A bearing system using a compliant surface may be so constructed that the lubricant pressure distribution is either stationary or in motion relative to the elastomer. In the latter case the motion of the deformation in the elastomer introduces inertial effects which can be important at high enough bearing velocities. This paper is concerned with the assessment of these effects. Steady state operating conditions are computed and analytical techniques presented for the infinite width slider and infinite length journal bearing.

Structural Damping of Self-Acting Compliant Foil Journal Bearings

1994 ◽  
Vol 116 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Hooshang Heshmat ◽  
C.-P. Roger Ku
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Test Facility ◽  
Structural Stiffness ◽  
Structural Damping ◽  
Equivalent Viscous Damping ◽  
Compliant Surface ◽  
Wide Range ◽  
Dynamic Forces

This paper describes an experimental investigation into the dynamic characteristics of corrugated foil (bump foil) strips used in compliant surface foil journal bearings and dampers. In the experimental method described herein, a test facility with a journal supported by a compliant foil journal bearing was built. The nonrotating journal was driven by two shakers which were used to simulate dynamic forces acting on bump foil strips. The dynamic structural stiffness and equivalent viscous damping coefficients are calculated based on the experimental measurements for a wide range of operating conditions. The results are compared to the analytical predictions obtained by a theoretical model developed earlier.

Analysis of magnetohydrodynamic partial slip laser bump texture slider and journal bearing

2019 ◽  
Vol 233 (12) ◽  
pp. 1921-1938 ◽  
Author(s):  
TVVLN Rao ◽  
Ahmad Majdi Abdul Rani ◽  
Norani Muti Mohamed ◽  
Hamdan Haji Ya ◽  
Mokhtar Awang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Performance Improvement ◽  
Uniform Magnetic Field ◽  
Journal Bearing ◽  
Load Capacity ◽  
Partial Slip ◽  
Slider Bearing ◽  
One Dimensional ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid

A model of magnetohydrodynamic partial slip laser texture bearing (slider and journal) is developed. The influence of laser bump texture and slip laser texture partial configuration on the magnetohydrodynamic performance analysis of bearing is presented. An electrically conducting fluid is confined to bearing surfaces under uniform magnetic field perpendicular to slider bearing and inclined to the line of maximum film thickness to journal bearing. A one-dimensional analysis based on the narrow groove theory is considered to evaluate the nondimensional pressure distribution in bearing. Results of the nondimensional load capacity and coefficient of friction of magnetohydrodynamic partial laser bump texture and partial slip laser texture bearing configurations are analyzed. Partial slip configuration under MHD lubrication without laser bump texture brings in the performance improvement.

A Theoretical Investigation of Compliant Surface Journal Bearings

1971 ◽  
Vol 93 (1) ◽  
pp. 191-201 ◽  
Author(s):  
M. K. Benjamin ◽  
V. Castelli
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Mathematical Problem ◽  
Ritz Method ◽  
Newton Iteration ◽  
Journal Bearings ◽  
Elasticity Problem ◽  
Algebraic Equations ◽  
Compliant Surface ◽  
Nonlinear Algebraic Equations

The problem of the compliant surface journal bearing is investigated. The mathematical problem is divided into two parts, the elasticity problem and the fluid problem. The equations of linear elasticity, which represent the elasticity problem, are solved; (a) by expansion of the solution in eigenfunctions (b) by the Raleigh Ritz method, and (c) by a collocation method. Reynolds’ equation, which represents the fluid problem, is then coupled with the solution to the elasticity problem. The corresponding finite difference representation of Reynolds’ equation, which is a set of fourth-order nonlinear algebraic equations, is inverted by Newton iteration. Finally, numerical results are presented.

Elastomer Viscoelasticity Effects in Compliant Surface Bearings

1973 ◽  
Vol 95 (3) ◽  
pp. 363-371 ◽  
Author(s):  
J. Pirvics ◽  
V. Castelli
Keyword(s):  
Steady State ◽  
Pressure Distribution ◽  
Journal Bearing ◽  
Analytical Techniques ◽  
Operating Conditions ◽  
Infinite Length ◽  
Compliant Surface ◽  
Viscoelastic Effects ◽  
Bearing System

A bearing system using a compliant surface may be so constructed that the lubricant pressure distribution is either stationary or in motion relative to the elastomer. In the latter case the motion of the deformation in the elastomer introduces viscoelastic effects which can be important at conventional bearing velocities. This paper is concerned with the assessment of these effects. Steady state operating conditions are computed and analytical techniques presented for the infinite width slider and infinite length journal bearing.

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