scholarly journals Finite Element Method Applied to the Eigenvalue Analysis of Flexible Rotors Supported by Journal Bearings

Engineering ◽  
2014 ◽  
Vol 06 (03) ◽  
pp. 127-137 ◽  
Author(s):  
Wéderley M. Miranda ◽  
Marco Tulio C. Faria
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Journal Bearings ◽  
Eigenvalue Analysis ◽  
Flexible Rotors ◽  
Element Method

Analysis of Aerodynamic Journal Bearings With Small Number of Herringbone Grooves by Finite Element Method

1994 ◽  
Vol 116 (4) ◽  
pp. 698-704 ◽  
Author(s):  
D. Bonneau ◽  
J. Absi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Study ◽  
Load Capacity ◽  
Journal Bearings ◽  
The Finite Element Method ◽  
Bearing Number ◽  
Comparison Of The Results ◽  
Herringbone Grooves ◽  
Element Method

A numerical study of gas herringbone grooved journal bearings is presented for small number of grooves. The compressible Reynolds equation is solved by use of the Finite Element Method. The nonlinearity of the discretized equations is treated with the Newton-Raphson procedure. A comparison of the results for a smooth bearing with previously published results is made and the domain of validity of the Narrow Groove Theory is analyzed. Load capacity, attitude angle, and stiffness coefficients are given for various configurations: groove angle and thickness of grooves, bearing number, and that for both smooth and grooved member rotating.

scholarly journals Tribology of High Speed Aerodynamic Foil Journal Bearings

1997 ◽  
Author(s):  
D. Sudheer Kumar Reddy ◽  
S. Swarnamani ◽  
B. S. Prabhu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Perturbation Technique ◽  
Journal Bearings ◽  
Rotating Shaft ◽  
Aerodynamic Pressure ◽  
Foil Bearing ◽  
Bearing Number ◽  
Element Method

Foil journal bearings come under the category of air lubricated journal bearings where the lubricant is atmospheric air. In this type of bearings the pressure developed is due to the aerodynamic wedge developed between the rotating shaft and the foil bearing surface. This paper is concerned with the analysis of the bending dominated type foil bearing, in which the compliance is effected mainly through the bending of foils. The nonlinear Reynolds equation has been used for the aerodynamic pressure solution. Effect of elastohydrodynamics on foil journal bearing has been studied. The problem has been formulated using incremental finite element method. Two types of bending dominated foil bearings have been considered for analysis, namely straight foil type and curved foil type bearings. The equations for the dynamic coefficients were obtained by a perturbation technique and the results were computed using the finite element method. The effect of bearing compliance and the bearing number on performance parameters has been studied, the results were compared with the available literature.

Numerical investigation on the static performance of aerostatic journal bearings with different pocket shapes by the finite-element method

2020 ◽  
pp. 135065012097911
Author(s):  
Xinglong Chen ◽  
James K Mills ◽  
Kai Shi ◽  
Gang Bao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Film Thickness ◽  
Journal Bearings ◽  
Orifice Diameter ◽  
Eccentricity Ratio ◽  
The Finite Element Method ◽  
Area Formula ◽  
Static Performance ◽  
Element Method

In this work, to improve the static behavior of aerostatic journal bearings, we examine the effect of pockets with different shapes, including the square, rectangular 1, rectangular 2, and circular, manufactured on the surface of the aerostatic journal bearing. The effects of the pocket shapes, pocket area [Formula: see text], eccentricity ratio ɛ, orifice diameter df, average gas film thickness h0, and misalignment angles [Formula: see text] and [Formula: see text] on the static performance are investigated using simulations. The Reynolds equation is solved by the finite-element method in this work. Simulations reveal that the pocket area [Formula: see text], eccentricity ratio ɛ, gas film thickness h0, orifice diameter df, and misalignment angles [Formula: see text] and [Formula: see text] have a significant influence on the load force F and the stiffness K. In general, rectangular 2 pocket bearings are found to perform somewhat better than bearings with other pocket shapes, with the pocket depth set to one-half of h0, when the pocket area [Formula: see text] varies from one-twelfth to one. The pocket area [Formula: see text] should be set according to the average gas film thickness h0 and the orifice diameter df to achieve a better static performance for the bearings. For bearings operated with misalignment angles [Formula: see text] and [Formula: see text], different pocket areas [Formula: see text] should be set according to the pocket shapes for the optimal design.

scholarly journals Analysis of Spiral-Grooved Gas Journal Bearings by the Narrow-Groove Theory and the Finite Element Method At Large Eccentricities

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Elia Iseli ◽  
Eliott Guenat ◽  
Roger Tresch ◽  
Jürg Schiffmann
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Pressure ◽  
Journal Bearings ◽  
The Finite Element Method ◽  
Pressure Profiles ◽  
Stability Maps ◽  
Time Periodic ◽  
Good Agreement ◽  
Element Method

Abstract A finite groove approach (FGA), based on the finite element method (FEM), is used for analyzing the static and dynamic behavior of spiral-grooved aerodynamic journal bearings at different eccentricities, number of grooves, and compressibility numbers. The results of the FGA are compared with the narrow-groove theory (NGT) solutions. For the rotating-groove case, a novel time-periodic solution method is presented for computing the quasi-steady-state and dynamic pressure profiles. The new method offers the advantage of avoiding time-consuming transient integration, while resolving a finite number of grooves. The static and dynamic solutions of the NGT and FGA approach are compared, and they show good agreement, even at large eccentricities (ε=0.8) and high compressibility numbers (Λ = 40). Stability maps at different eccentricities are presented. At certain operation points, a stability decrease toward larger eccentricities is observed. The largest stability deviations of the NGT from the FGA solutions occur at large groove angle, low number of grooves, and large compressibility numbers.

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