Steady-State Characteristics of Aerostatic Porous Rectangular Thrust Bearings Incorporating the Effects of Velocity Slip, Anisotropy and Tilt

1983 ◽  
Vol 197 (3) ◽  
pp. 179-188 ◽  
Author(s):  
K C Singh ◽  
N S Rao ◽  
B C Majumdar
Keyword(s):  
Steady State ◽  
Load Capacity ◽  
Velocity Slip ◽  
Generalized Solution ◽  
Static Stiffness ◽  
Mass Rate ◽  
Thrust Bearings ◽  
Design Charts ◽  
Mass Flowrate ◽  
Steady State Performance

A generalized solution is presented in order to predict the steady-state performance characteristics of aerostatic porous rectangular thrust bearings of finite pad thickness. The analysis takes into account the Beavers-Joseph criterion for velocity slip at the bearing interface, the anisotropy of the porous material and the tilt of the bearing. Dimensionless load capacity, mass flowrate of the gas and static stiffness are computed numerically for different operating parameters and bearing dimensions and presented in the form of design charts. The effect of slip is to reduce the load capacity and increase the mass rate of flow.

Effect of Slip Flow on the Steady-State Performance of Aerostatic Porous Journal Bearings

1984 ◽  
Vol 106 (1) ◽  
pp. 156-162 ◽  
Author(s):  
K. C. Singh ◽  
N. S. Rao ◽  
B. C. Majumdar
Keyword(s):  
Steady State ◽  
Slip Velocity ◽  
Load Capacity ◽  
Finite Thickness ◽  
Slip Flow ◽  
Velocity Slip ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Mass Rate ◽  
Steady State Performance

A theoretical solution is presented to predict the steady-state performance characteristics of aerostatic porous journal bearings of finite thickness considering three dimensional flow in the porous media. The analysis takes into account the velocity slip at the film bearing interface by using Beavers-Joseph criterion. Results are presented in dimensionless form for load capacity and mass rate of flow for different operating conditions and bearing dimensions. Solution is also obtained for modified slip velocity conditions and both the results are compared. It is observed that there is no agreement between two models except for few values of slip parameters. Hence, it is preferable to use the Beavers-Joseph model in order to account for all values of slip parameters. The effect of slip velocity on the static characteristics is discussed.

Static Axial Characteristics of Aerostatic Annular Porous Thrust Bearings with Tilt

1983 ◽  
Vol 197 (2) ◽  
pp. 83-88 ◽  
Author(s):  
K C Singh ◽  
N S Rao ◽  
B C Majumdar
Keyword(s):  
Gas Flow ◽  
Load Capacity ◽  
Three Dimensional ◽  
Graphical Form ◽  
Axial Stiffness ◽  
Mass Rate ◽  
Thrust Bearings ◽  
Bearing Clearance ◽  
Mass Flowrate ◽  
Flow Through

A theoretical analysis is presented to predict the static axial performance characteristics of a porous circular thrust bearing with a central hole for both open and sealed ends, taking into consideration the tilt of the runner pad. The flow in the bearing matrix is considered to be three-dimensional. The governing equations of gas flow through the porous pad and the bearing clearance are solved simultaneously using the finite difference technique to obtain pressure distribution in the bearing clearance. The load capacity, mass rate of flow and static axial stiffness are calculated numerically for various bearing dimensions and supply conditions and presented in graphical form. The bearings with sealed ends have comparatively better load capacity over those with unsealed ends. The effect of tilt is to decrease the load capacity and increase the mass flowrate.

Hybrid Porous Gas Journal Bearings: Steady State Solution Incorporating the Effect of Velocity Slip

1984 ◽  
Vol 106 (3) ◽  
pp. 322-328 ◽  
Author(s):  
K. C. Singh ◽  
N. S. Rao ◽  
B. C. Majumdar
Keyword(s):  
Steady State ◽  
Reynolds Equation ◽  
Stokes Equations ◽  
Load Capacity ◽  
Velocity Slip ◽  
Steady State Solution ◽  
Static Characteristic ◽  
Journal Bearings ◽  
Mass Rate ◽  
Modified Reynolds Equation

A theoretical analysis is presented to predict the steady state performance characteristics of externally pressurized rotating gas journal bearings incorporating the effect of velocity slip at the porous interface. The governing equation for flow in the porous media and the modified Reynolds equation derived from the Navier-Stokes equations satisfying the velocity slip boundary condition, are solved simultaneously for film pressure distribution. Due to the nonlinearity of modified Reynolds equation the solution is obtained by perturbation method using finite difference technique. The dimensionless load capacity, attitude angle and mass rate of flow are computed numerically for different operating parameters. The effect of slip on the static characteristic is discussed. Comparison of the results with similar available solution for the no-slip case shows good agreement.

Behavior of Thermal Effects and Velocity-Slip on Performance of Externally Pressurized Porous Incompressible Gas Thrust Bearing

1979 ◽  
Vol 46 (2) ◽  
pp. 465-468 ◽  
Author(s):  
V. K. Kapur ◽  
J. S. Yadav
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Effects ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Velocity Slip ◽  
Experimental Results ◽  
Slip Condition ◽  
Static Stiffness

In the present analysis, the interactions of thermal effects and velocity slip on the performance of externally pressurized porous incompressible gas thrust bearing have been studied. Numerical results for load capacity, mass flow rate, and static stiffness have been obtained and their behavior is illustrated in figures. The results for slip as well as no-slip condition have also been compared with the experimental results of Gargiulo and Gilmour [7].

Static and Dynamic Performance of an Infinite Stiffness Hydrostatic Thrust Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 106-112 ◽  
Author(s):  
N. Tully
Keyword(s):  
Steady State ◽  
Vibration Analysis ◽  
Thrust Bearing ◽  
Dynamic Performance ◽  
Cone Angle ◽  
Vibration Absorber ◽  
Static Stiffness ◽  
Load Range ◽  
Normal Diaphragm ◽  
Steady State Performance

A novel form of variable hydrostatic restriction is proposed which will automatically achieve a high, infinite or negative static stiffness over a substantial load range. The restrictor is formed between the bearing body and a spring mounted conical plug. The steady state performance is analyzed and design curves presented which are valid for any cone angle from zero, i.e., fixed clearance, to 90 deg which is the normal diaphragm restrictor. The dynamic response to forced sinusoidal vibrations is examined in conventional vibration analysis form and it is found that the restrictor system may be designed to act as a vibration absorber.

Numerical and experimental study on the static performance of externally pressurized thrust bearings lubricated with refrigerant gases

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chengjun Rong ◽  
Huaqi Lian ◽  
Yulong Li
Keyword(s):  
Heat Pump ◽  
Stokes Equations ◽  
Load Capacity ◽  
Heat Pumps ◽  
Static Stiffness ◽  
Space Applications ◽  
Content Type ◽  
Thrust Bearings ◽  
Bearing Clearance ◽  
Static Performance

Purpose Oil-free heat pumps that use the system refrigerant gases as lubricants are preferred for thermal management in future space applications. This study aims to numerically and experimentally investigate the static performance of externally pressurized thrust bearings lubricated with refrigerant gases. Design/methodology/approach The refrigerant gases R22, R410A and CO2 were chosen as the research objects, while N2 was used for comparison. Computational fluid dynamics was used to solve the full 3 D Navier–Stokes equations to determine the load capacity, static stiffness and static pressure distribution in the bearing film. The numerical results were experimentally verified. Findings The results showed that the refrigerant-gas-lubricated thrust bearings had a lower load capacity than the N2-lubricated bearings, but they presented a higher static stiffness when the bearing clearance was less than 9 µm. Compared with the N2-lubricated bearings, the optimal static stiffness of the R22- and CO2-lubricated bearings increased by more than 46% and more than 21%, respectively. The numerical and experimental results indicate that a small bearing clearance would be preferable when designing externally pressurized gas thrust bearings lubricated with the working medium of heat pump systems for space applications. Originality/value The findings of this study can serve as a basis for the further investigation of refrigerant gases as lubricants in heat pump systems, as well as for the future design of such gas bearings in heat pump systems for space applications.

An Analysis of the Steady State and Dynamic Characteristics of a Spherical Hydrodynamic Journal Bearing

1989 ◽  
Vol 111 (3) ◽  
pp. 459-467 ◽  
Author(s):  
P. S. Leung ◽  
I. A. Craighead ◽  
T. S. Wilkinson
Keyword(s):  
Steady State ◽  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Axial Forces ◽  
Design Charts ◽  
Spherical Surfaces ◽  
Recent Developments ◽  
Hydrodynamic Journal Bearing ◽  
Bearing Design ◽  
Steady State Performance

With recent developments in N. C. manufacturing processes it is relatively straightforward to produce a journal bearing with spherical surfaces. Such a bearing offers two main advantages over a conventional bearing: it can tolerate much larger misalignment and it can resist axial forces. In this paper, the steady state performance of a spherical journal bearing is studied by using a finite bearing theory. The dynamic characteristics of the bearing are represented by eight displacement and velocity force coefficients and the boundary of bearing stability is determined. The effect of superlaminar flow upon the bearing performance is also studied, and typical bearing design charts are provided. In comparison, the behavior of the spherical journal bearing is found to be similar to that of an equivalent cylindrical bearing.

Steady-state performance analysis of misaligned double-layered porous journal bearings under coupled-stress lubrication with slip flow and additives percolation effect

2018 ◽  
Vol 233 (6) ◽  
pp. 841-858 ◽  
Author(s):  
Shitendu Some ◽  
Sisir K Guha
Keyword(s):  
Steady State ◽  
Performance Analysis ◽  
Slip Flow ◽  
Velocity Slip ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Graphical Form ◽  
Percolation Effect ◽  
Coupled Stress ◽  
Steady State Performance

The aim of this paper is to address the effect of misalignment of the double-layered porous journal bearing on the steady-state performance analysis under coupled-stress lubrication with velocity phenomenon at the fine porous interface. Here, the misalignment caused by shaft displacement, e.g. axial (vertical displacement) and twisting (horizontal displacement) is considered. This analysis includes velocity slip phenomenon on the basis of Beavers-Joseph criteria. Moreover, the present analysis also focuses on the percolation effect of the additives into the pores of the porous layers. Steady-state film pressures are obtained by solving the modified Reynolds equation based on the coupled-stress lubrication theory. Under various parametric conditions, pressure profiles in the film region are discussed and demonstrated in the graphical form. Using these film pressure values, steady-state characteristics in terms of bearing load carrying capacity, attitude angle, frictional parameter, side leakage and misalignment moment are evaluated at various parametric conditions and represented in the graphical form.

Sign in / Sign up

Export Citation Format

Share Document