Performance characteristics of an elliptic hydrostatic bearing and comparative analysis based on Stokes’ conditions

2012 ◽  
Vol 223 (6) ◽  
pp. 1187-1198 ◽  
Author(s):  
Bilal M. A. Maher
Author(s):  
Leonid Moroz ◽  
Leonid Romanenko ◽  
Roman Kochurov ◽  
Evgen Kashtanov

Abstract Hydrostatic bearings are widely used in industry, including aerospace and energy sectors. Hydrodynamic lubrication mechanism has been well studied analytically and experimentally and various types of bearings were developed to provide increasing operating speed, load capacity, stability and efficiency for modern rotating machines. Hydrostatically lubricated bearings have principal difference (in comparison with hydrodynamic bearings) and their characteristics have been an area of continued research. The goal of this work is to develop a robust algorithm, which can predict hydrodynamical characteristics and dynamic stiffness and damping coefficients of hybrid and hydrostatic bearings with increased accuracy and which can be used for engineering/design purposes. The developed approach is based on Reynold’s equations, where the unknown parameters are the rotor position and fluid pressure in recess pockets. Finite difference method in combination with the successive over-relaxation algorithm is used for a numerical solution of Reynold’s equations. Newton’s method is applied to solve the generated system of equations. Applying the developed approach, the effect of load influence on the hydrodynamical and the dynamic stiffness characteristics has been studied. Several hydrostatic bearing designs which are based on the published data were considered to compare the results calculated applying the approach with the experimental and theoretical data given in the literature. Performed study shows when journal eccentricity can’t be neglected while simulating hydrostatic bearing characteristics. Simulations also allow for analysis of how different design/geometrical parameters and initial conditions (supply pressure) influence bearing performance characteristics. The developed approach can be utilized as a practical tool which allows for the prediction of performance characteristics of hydrostatic bearing with increased accuracy.


Author(s):  
Asma Abed ◽  
Ahmed Bouzidane ◽  
Marc Thomas ◽  
Hamou Zahloul

A numerical analysis is carried out in order to investigate the effect of the electric field on the performance characteristics of a three-pad hydrostatic squeeze film damper compensated with new electrorheological valve restrictors. The bearing design is composed of three identical hydrostatic bearing pads. Each hydrostatic bearing pad is fed with a negative electrorheological fluid through an electrorheological valve. The numerical analysis showed that the viscosity of a smart fluid inside to each electrorheological valve can be controlled by using an electric field in order to control the static and dynamic characteristics. The results presented in this study can be made more useful to control rotor vibrations and force transmissibility especially around the critical speeds.


2012 ◽  
Vol 616-618 ◽  
pp. 1801-1807
Author(s):  
Man Li Ou ◽  
Wei Jun Cao ◽  
Long Min Jiang ◽  
Hui Cao

Through the analysis of the development status and application of steel structures in China, the author described the hazards of fire on steel structures and the importance of fire protection for steel structures, introduced the most commonly used fire protection methods for steel structures and meanwhile conducted comparative analysis of several fire-resistant coatings for steel structures to detail the performance characteristics of fire-resistant coatings for the thick, thin and ultra-thin steel structures. In addition, through project examples, the author puts forward choices and construction requirements of steel structures fire-resistant coatings in fire prevention design.


2010 ◽  
Vol 53 (3) ◽  
pp. 356-361 ◽  
Author(s):  
V. M. Abazov ◽  
G. D. Alexeev ◽  
Yu. I. Davydov ◽  
V. L. Malyshev ◽  
V. V. Tokmenin ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document