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.

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.

Investigation on influences of herringbone grooves for the aerostatic journal bearings applied to ultra-high-speed spindles

2019 ◽  
Vol 233 (16) ◽  
pp. 5795-5812 ◽  
Author(s):  
Siyu Gao ◽  
Yungao Shi ◽  
Linsen Xu ◽  
Hong Chen ◽  
Kai Cheng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Journal Bearings ◽  
Sensitivity Analyses ◽  
Geometrical Parameters ◽  
High Speeds ◽  
Ultra High Speed ◽  
Herringbone Grooves ◽  
Element Method

Aerostatic bearings are the core parts of ultra-high-speed spindles with maximum running speed greater than 100,000 r/min. In this paper, the influences of herringbone grooves on the performance of aerostatic journal bearings are studied to design spindles with the features of higher precision and higher speed. Parametric studies and sensitivity analyses are executed in terms of the improved finite element method, which is specially developed to solve the compressible Reynolds equation for herringbone grooved air bearings. The calculated results indicate that herringbone grooves significantly improve the performance of aerostatic journal bearings under the conditions of ultra-high speeds and low supply pressures. Groove parameters are nonlinear dependent, and groove depth and length are the dominant influential factors for the load capacity at speed of 200,000 r/min. Experiments are designed and conducted to verify the improved finite element method, which show that the improved finite element method can be used to analyze the influences of herringbone grooves on aerostatic journal bearings and also manifest that suitable herringbone groove geometrical parameters can obviously decrease spindle radial runouts at ultra-high speeds.

scholarly journals Design and Structural Analysis of a SWATH type vessel using the Finite Element Method and its response to Slamming events

2020 ◽  
Vol 14 (27) ◽  
pp. 55-66
Author(s):  
Hugo Leonardo Murcia Gallo ◽  
Richard Lionel Luco Salman ◽  
David Ignacio Fuentes Montaña
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Load Condition ◽  
Structural Response ◽  
Water Area ◽  
The Finite Element Method ◽  
Short Period ◽  
Classification Society ◽  
Element Method

The main objective of this study is to analyze the structural response of a boat during a slamming event using the Finite Element Method in a Small Water Area Twin Hull (SWATH) type boat.  In the mentioned load condition, the acceptance criteria established by a classification society must be fulfilled, taking into account the areas where this event affects the structure such as the junction deck, the pontoons and other structural members established by the standard, all this generated by the high pressure loads in the ship's structure in a very short period of time being an element of study in this type of vessels, as long as they are within the range of high speed vessels. Among the main results of this study were the deformations and stresses in the structure obtained under the reference parameters of the classification society.

Modeling and Simulation of High Speed Intermittent Cutting Based on the Finite Element Method

2013 ◽  
Vol 683 ◽  
pp. 556-559
Author(s):  
Bin Bin Jiao ◽  
Fu Sheng Yu ◽  
Yun Jiang Li ◽  
Rong Lu Zhang ◽  
Gui Lin Du ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Field ◽  
Cutting Force ◽  
High Speed ◽  
Element Model ◽  
Periodic Variation ◽  
Element Analysis ◽  
Intermittent Cutting ◽  
Element Method

In order to study the distribution of the stress field in the high-speed intermittent cutting process, finite element model of high-speed intermittent cutting is established. Exponential material model of the constitutive equation and adaptive grid technology are applied in the finite element analysis software AdvantEdge. The material processing is simulated under certain cutting conditions with FEM ( Finite Element Method ) and the distribution of cutting force, stress field, and temperature field are received. A periodic variation to the cutting force and temperature is showed in the simulation of high-speed intermittent cutting. Highest value of the milling temperature appears in front contacting area of the knife -the chip.and maximum stress occurs at the tip of tool or the vicinity of the main cutting edge. The analysis of stress and strain fields in-depth is of great significance to improve tool design and durability of tool.

Explicit Finite Element Simulation of Granular Flow in an Annular Shear Cell

2009 ◽  
Author(s):  
M. A. Kabir ◽  
C. F. Higgs ◽  
M. R. Lovell ◽  
V. Jasti ◽  
M. C. Marinack
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Granular Flow ◽  
High Speed ◽  
Flow Behavior ◽  
Shear Cell ◽  
Explicit Finite Element Method ◽  
Explicit Finite Element ◽  
Annular Shear Cell ◽  
Element Method

Explicit finite element method modeling of granular flow behavior in an annular shear cell has been studied and presented in this paper. The explicit finite element method (FEM) simulations of granular flow in an annular shear cell with around 1633 particles were performed, where the inner wheel rotated at a very high speed and the outer disk remained stationary. The material properties of the particles and the outer wheel were defined as elastic steel whereas the inner wheel was elastic aluminum. In this investigation, the explicit FEM model mimicked granular flow in an experimental set up where the inner wheel was rotated at a speed of 240 rpm. The FEM results for shearing motion and solid fraction were compared with experimental results from a granular shear cell.

Calculation of Heat Distribution in High Speed Cutting Based on Finite Element Method

2009 ◽  
Vol 626-627 ◽  
pp. 249-254
Author(s):  
Wang Yu Liu ◽  
X.K. Liu ◽  
Jing Li ◽  
Yong Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Experimental Result ◽  
Analytic Method ◽  
Heat Distribution ◽  
Analytic Model ◽  
The Finite Element Method ◽  
High Speed Cutting ◽  
Element Method

Combined the analytic method with the finite element method, the data necessary for calculating the heat distribution ratio for high speed cutting was mined first, and the experimental result was used to validate the authenticity of finite element modeling. Then, the ratio of heat distribution for high speed cutting based on the analytic model was obtained by customizing the special subroutine developed by the authors, which provides a new method for calculating the heat distribution.

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