Rapid and globally convergent method for dynamically loaded journal bearing design

1998 ◽  
Vol 212 (3) ◽  
pp. 207-214 ◽  
Author(s):  
H Hirani ◽  
K Athre ◽  
S Biswas
Keyword(s):  
Journal Bearing ◽  
Pressure Curve ◽  
Algebraic Equations ◽  
Connecting Rod ◽  
Main Bearing ◽  
Element Analysis ◽  
Globally Convergent ◽  
Dynamically Loaded ◽  
Convergent Method ◽  
Bearing Design

An approximate analytical pressure expression for dynamically loaded journal bearings is proposed. This approximation is applied to the solution of the finite journal bearing with a π-extent film. The starting and ending angular positions of the pressure curve are predicted by simple algebraic equations. The journal orbit is determined by treating it as an ‘inverse problem’ and evaluated by using the globally convergent Newton-Raphson method. To illustrate the validity of the present study, the Ruston and Hornsby big-end connecting rod bearing and an engine main bearing are analysed. The accuracy of the minimum film thickness and maximum film pressure values obtained by the proposed methodology is comparable to the more elaborate and time consuming finite element analysis, while the execution time is comparable to that required for the short bearing approximation.

Analytical Curve Fits for Solution Parameters of Dynamically Loaded Journal Bearings

1984 ◽  
Vol 106 (4) ◽  
pp. 421-427 ◽  
Author(s):  
P. K. Goenka
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Solution Time ◽  
Pressure Curve ◽  
Element Analysis ◽  
Analytical Curve ◽  
Dynamically Loaded ◽  
Method Of Solution ◽  
Mobility Method ◽  
Solution Accuracy

The mobility method of solution is frequently used for analyzing dynamically loaded journal bearings. Curve fits of journal-bearing solutions are used in this method. All the currently available curve fits are lacking in one or more of three important features—the solution accuracy, the solution detail, and the solution time. A new set of analytical curve fits is presented in this paper. The set includes: the two components of mobility vectors, location and magnitude of maximum film pressure, and the starting and finishing angles of the pressure curve. For an ideal journal bearing, the new curve fits give accuracy and solution detail comparable to an expensive finite-element analysis, while keeping the solution time comparable to that required for the short-bearing approximation. An example is presented to demonstrate the use of the new curve fits.

Dynamically Loaded Finite Length Journal Bearings: Analytical Method of Solution

1999 ◽  
Vol 121 (4) ◽  
pp. 844-852 ◽  
Author(s):  
H. Hirani ◽  
K. Athre ◽  
S. Biswas
Keyword(s):  
Pressure Distribution ◽  
Closed Form ◽  
Analytical Method ◽  
Journal Bearings ◽  
Positive Pressure ◽  
Maximum Pressure ◽  
Pressure Curve ◽  
Connecting Rod ◽  
Dynamically Loaded ◽  
Form Pressure

A closed-form pressure distribution, using a combination of short- and long-bearing approximations, is proposed for dynamically loaded journal bearings. The angles for start and finish of positive pressure curve are determined employing simple analytical equations. The mobility method, based on the suggested pressure distribution is easy to use, predicts results of acceptable accuracy and the execution time is comparable to that required for the short bearing approximation. This paper also provides a conceptually simple analytical method for evaluating angular location of the instantaneous maximum pressure using proposed closed form pressure distribution. Simple algebraic equations are derived to obtain the instantaneous maximum pressure in dynamically loaded bearings directly, without involving any iteration. To illustrate the validity of present study, a connecting rod big end bearing and two crankshaft main bearings are analyzed. The mobility components, minimum film thickness and maximum pressure are plotted over a load cycle and compared with established analytical and curve fit methods. The results are also compared with those obtained using finite element method.

Paper 8: An Investigation into the Performance of Dynamically Loaded Journal Bearings: Design Study

1966 ◽  
Vol 181 (2) ◽  
pp. 28-34 ◽  
Author(s):  
T. Lloyd ◽  
R. Horsnell ◽  
H. McCallion
Keyword(s):  
Maximum Load ◽  
Design Parameters ◽  
Maximum Pressure ◽  
Inlet Temperature ◽  
Connecting Rod ◽  
Main Bearing ◽  
Bulk Oil ◽  
Engine Design ◽  
Dynamically Loaded ◽  
Bearing Loads

The objects of this paper are to demonstrate the use of the method described in Paper 6 and to give an indication of the effect of design parameters on the performance of a dynamically loaded bearing. An investigation into the main and big-end bearings of a diesel engine of modern design is described. The performance of a bearing is gauged by obtaining: (a) the minimum oil film thickness, (6) the maximum pressure developed within the oil, (c) the maximum load/projected area, and ( d) the bulk oil temperature rise. The influence of the engine design upon the big-end bearing performance for the particular engine under consideration is found by investigating the effects of the following parameters: ( a) bearing length-diameter ratio, (6) removal of centre-circumferential groove, ( c) inlet temperature, ( d) bearing clearance, and ( e) loading diagram. This last parameter is varied by changing in turn the piston mass, the connecting-rod mass, and the position of the connecting-rod centre of gravity. Finally, the effect upon the main bearing performance of various balance weight configurations is demonstrated. The usual assumption is made to obtain the main bearing loads: that loads imposed by a crank throw are equally distributed between neighbouring main bearings. General conclusions are made regarding the relative influence of certain bearing-design parameters upon the bearing performance.

Analysis of Dynamically Loaded Floating Bush Bearing With Flexible Shaft in Flexible Anisotropic Bearing Used in Textile Application

2008 ◽  
Author(s):  
D. C. Patel ◽  
D. P. Vakharia
Keyword(s):  
Journal Bearing ◽  
Reducing Power ◽  
Design Concept ◽  
Potential Contribution ◽  
Oil Whip ◽  
Excited Vibration ◽  
Textile Machine ◽  
Minimum Film Thickness ◽  
Dynamically Loaded ◽  
Bearing Design

A FLOATING bush bearing is a kind of bearing which has a thin bush floating freely between journal and fixed bush. In recent years considerable attention has been paid to the “vibration suppressing effect” of floating us bearing. It is reported that floating bush bearing are, if properly designed, effective in suppressing both resonant vibrations at the critical speed and self excited vibration call oil whip. This study deal with performance of dynamically loaded floating ring journal bearing and investigates their feasibility for two for one textile machine application. A mathematical model is developed and its analysis for performance of floating bush journal bearing with flexible shat in flexible anisotropic bearing is conducted. The potential contribution of the floating bush journal bearing design concept to reduce vibration is assessed and its compliance with current bearing durability criteria is evaluated. The result indicates that the adoption of floating bush design concept has potential for reducing power loss and vibration in two for one (TFO) textile machine bearing. It is shown that this can be accomplished without violating minimum film thickness constraints currently accepted as criteria for successful machine bearing operation.

An Evaluation of Eight-Node Quadrilateral Finite Elements for the Analysis of a Dynamically Loaded Hydrodynamic Journal Bearing

1988 ◽  
Vol 202 (2) ◽  
pp. 95-101 ◽  
Author(s):  
J D C McIvor ◽  
D N Fenner
Keyword(s):  
Finite Element Analysis ◽  
Journal Bearing ◽  
Computer Time ◽  
Medium Size ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dynamically Loaded ◽  
Hydrodynamic Journal Bearing ◽  
Triangular Elements ◽  
Solution Accuracy

A comparative study is presented for the finite element analysis of a dynamically loaded journal bearing showing the improvement in solution accuracy and decrease in computer time achieved when using eight-node quadilateral, rather than three-node triangular, elements. Results are presented for medium size diesel engine big end bearings using a wide variety of mesh gradings.

Thermal Effects in Dynamically Loaded Flexible Journal Bearings

1989 ◽  
Vol 111 (1) ◽  
pp. 49-55 ◽  
Author(s):  
H. Moes ◽  
P. B. Y. Ten Hoeve ◽  
J. Van der Helm
Keyword(s):  
Temperature Distribution ◽  
Viscous Dissipation ◽  
Heat Generation ◽  
Thermal Effects ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Connecting Rod ◽  
Lubricant Flow ◽  
Dynamically Loaded

A method of taking into account the thermal effects when simulating dynamically loaded, flexible, journal bearings on a computer will be introduced. The method is an extension of Van der Tempel’s model for a flexible, short journal bearing under severe dynamic duty, with partial circumferential supply grooves, cavitation and cavitation induced starvation. It incorporates the heat generation due to the viscous dissipation and the cooling due to the axial and circumferential flow of lubricant. The results for the film thicknesses, the lubricant flow, the viscous dissipation and the temperature distribution in two specific connecting-rod bearing configurations will be presented.

Convexity of a discrete Carleman weighted objective functional in an inverse medium scattering problem

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nguyen Trung Thành
Keyword(s):  
Finite Number ◽  
Scattering Problem ◽  
One Dimensional ◽  
Globally Convergent ◽  
Convergent Method ◽  
Inverse Medium ◽  
Inverse Medium Scattering ◽  
Objective Functional

AbstractWe investigate a globally convergent method for solving a one-dimensional inverse medium scattering problem using backscattering data at a finite number of frequencies. The proposed method is based on the minimization of a discrete Carleman weighted objective functional. The global convexity of this objective functional is proved.

scholarly journals Pivoted-Pad Journal Gas Bearing Performance in Exploratory Operation of Brayton Cycle Turbocompressor

1968 ◽  
Vol 90 (4) ◽  
pp. 687-696 ◽  
Author(s):  
R. Y. Wong ◽  
W. L. Stewart ◽  
H. E. Rohlik
Keyword(s):  
Experimental Study ◽  
Journal Bearing ◽  
Inert Gas ◽  
Brayton Cycle ◽  
Ambient Conditions ◽  
Operating Characteristics ◽  
The Third ◽  
Loading Device ◽  
Bearing Design ◽  
Gas Bearing

This paper describes findings obtained to date in the area of journal gas bearings from an experimental study of a Brayton cycle turbocompressor designed for the requirements of a two-shaft 10-kw space power system. The journal bearing design utilizes three pads pivoted on conforming balls and sockets. Two of the pivots are rigidly mounted to the frame, and the third pivot is mounted to the frame through a low-spring-rate diaphragm. This paper describes the salient package and bearing design features and then presents the principal results obtained from testing the package in both a spin calibration rig and operation at design temperature conditions with an inert gas. The results discussed include (a) the successful use of a pneumatic loading device to vary pad load during operation, (b) the operating characteristics of the bearings as obtained over a range of pad loads and ambient conditions, (c) structural and dynamic behavior of the bearing-support system during design temperature operation and (d) a discussion of the wear characteristics of the conforming ball-and-socket pivot as obtained from the tests made to date.

scholarly journals A derivative free globally convergent method and its deformations

2021 ◽  
Author(s):  
Manoj Kumar Singh ◽  
Arvind K. Singh
Keyword(s):  
Difference Operator ◽  
Linear Equations ◽  
Numerical Test ◽  
Test Functions ◽  
Globally Convergent ◽  
Forward Difference ◽  
Derivative Free ◽  
Fractal Patterns ◽  
Convergent Method ◽  
Non Linear Equations

AbstractThe motive of the present work is to introduce and investigate the quadratically convergent Newton’s like method for solving the non-linear equations. We have studied some new properties of a Newton’s like method with examples and obtained a derivative-free globally convergent Newton’s like method using forward difference operator and bisection method. Finally, we have used various numerical test functions along with their fractal patterns to show the utility of the proposed method. These patterns support the numerical results and explain the compactness regarding the convergence, divergence and stability of the methods to different roots.

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