Numerical Calculation and Analysis of Dynamic Pressure Effect for Heavy Hydrostatic Bearing Disk with Multiple Oil Pads

2011 ◽  
Vol 4 (8) ◽  
pp. 2561-2565 ◽  
Author(s):  
Junpeng Shao ◽  
Chunxi Dai ◽  
Xiaoqiu Xu ◽  
Yunfei Wang ◽  
Yanqin Zhang ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Pressure Effect ◽  
Dynamic Pressure ◽  
Hydrostatic Bearing

FUNDAMENTAL ANALYSIS OF THREE-DIMENSIONAL ‘NEAR FLING’

1993 ◽  
Vol 183 (1) ◽  
pp. 217-248 ◽  
Author(s):  
S. Sunada ◽  
K. Kawachi ◽  
I. Watanabe ◽  
A. Azuma
Keyword(s):  
Numerical Calculation ◽  
Hydrodynamic Force ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Added Mass ◽  
Opening Angle ◽  
Rotation Axes ◽  
Adequate Accuracy ◽  
Series Of Experiments ◽  
The Moment

A series of experiments on three-dimensional ‘near fling’ was carried out. Two pairs of plates, rectangular and triangular, were selected, and the distance between the rotation axes of the two plates of each pair was varied. The motion of the plates as well as the forces and the moment were measured, and the interference between the two plates of a pair was studied. In addition, a method of numerical calculation was developed to aid in the understanding of the experimental results. The interference between the two plates of a pair, which acted to increase both the added mass of each plate and the hydrodynamic force due to dynamic pressure, was noted only when the opening angle between the plates was small. The hydrodynamic forces were strongly influenced by separated vortices that occurred during the rotation. A method of numerical calculation, which took into account the effect both of interference between the plates and of separated vortices, was developed to give adequate accuracy in analyzing beating wings in ‘near fling’.

scholarly journals Study on dynamic characteristics of gas films of spherical spiral groove hybrid gas bearings

2019 ◽  
Vol 233 (8) ◽  
pp. 1169-1181
Author(s):  
Chenhui Jia ◽  
Haijiang Zhang ◽  
Shijun Guo ◽  
Ming Qiu ◽  
Wensuo Ma ◽  
...  
Keyword(s):  
Pressure Effect ◽  
Dynamic Pressure ◽  
Iteration Algorithm ◽  
Unstable State ◽  
Gas Bearings ◽  
Damping Coefficients ◽  
The Stability ◽  
Stiffness And Damping ◽  
Film Stiffness ◽  
Gas Bearing

According to the gas film force variation law, when the bearing axis is slightly displaced from the static equilibrium position, displacement and velocity disturbance relation expressions for the gas film force increment are constructed. Moreover, combined with the bearing rotor system motion equation, calculation model equations for the gas film stiffness and damping coefficients are established. The axial and radial vibration and velocity of the gas bearings during operation are collected. The instantaneous stiffness and damping coefficients of the gas film are calculated by the rolling iteration algorithm using MATLAB. The dynamic changes in the gas film stiffness and damping under different motion states are analyzed, and the mechanism of the gas film vortex and oscillation is studied. The results demonstrate the following: (1) When the gas bearing is running in the linear steady state in cycle 1, the dynamic pressure effect is enhanced and the stability is improved by increasing the eccentricity; when the gas supply pressure is increased, the static pressure effect is enhanced and the gas film vortex is reduced, but the oscillation is strengthened. (2) With the increase in rotational speed, the gas film vortex force gradually exceeds the gas film damping force, and the stability gradually worsens, causing a fluctuation in the gas film stiffness and damping, following which singularity occurs and a half-speed vortex is formed. Meanwhile, the gas film oscillation is intensified, and the rotor enters the nonlinear stable cycle 2 state operation. (3) As the fluctuation of the film force increases, the instantaneous stiffness and damping oscillation of the film intensifies, most of the stiffness and damping coefficients exhibit distortion, and the rotor operation will enter a chaotic or unstable state. Therefore, the gas bearing stiffness and damping variation characteristics can be used to study and predict the gas bearing operating state. Finally, measures for reducing the vortex and oscillation of the gas film and improving the stability of the gas bearing operation are proposed.

Three-Dimensional CFD Simulation for Water-Lubricated Guide Bearing of Large Tubular Pump

2014 ◽  
Vol 574 ◽  
pp. 160-166
Author(s):  
Hua Rong Xin ◽  
Ming Yue Zhang
Keyword(s):  
Cfd Simulation ◽  
Pressure Effect ◽  
Load Capacity ◽  
Dynamic Pressure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Water Film ◽  
Static Characteristics ◽  
Pressure Distributions ◽  
High Speeds

A numerical simulation for flow field in water-lubricated guide bearing of large tubular pump is conducted by software Fluent, which shows the pressure distribution of water film with different rotating speeds and the rule of the influence of relevant parameters on the amount of lubricating water, dynamic and static characteristics of guide bearing.The result shows that the pressure distributions of water film at low and high speeds are very different, and with the obvious dynamic pressure effect, the bearing inner can be in a state of reflux and the water-lubricated amount and clearance are reduced. The load capacity and stiffness of guide bearing are increased along with the speed and water pressure increase meanwhile the amount of water is increased along with the speed lowering and the water pressure and clearance increase.

Dynamic pressure effect on horse and horse rider during riding

2014 ◽  
Vol 17 (3) ◽  
pp. 143-150 ◽  
Author(s):  
Graeme Nicol ◽  
Graham P. Arnold ◽  
Weijie Wang ◽  
Rami J. Abboud
Keyword(s):  
Pressure Effect ◽  
Dynamic Pressure

Influence of Working Parameters on Dynamic Pressure Effect of Heavy Constant Flow Hydrostatic Center Rest

2013 ◽  
Vol 274 ◽  
pp. 82-86
Author(s):  
Bo Wu ◽  
Xiao Dong Yu ◽  
Xue Mei Chang ◽  
Chao Yin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Field ◽  
Pressure Effect ◽  
Dynamic Pressure ◽  
Lubricating Oil ◽  
Constant Flow ◽  
Oil Film ◽  
Working Parameters ◽  
Volume Method

In order to increase the working performance of a heavy constant flow hydrostatic center rest, a theoretical study concerning the lubricating oil film dynamic pressure effect of the heavy constant flow hydrostatic center rest is described. The Computational Fluid Dynamics and the Finite Volume Method have been used to compute numerically the static pressure field and the total pressure field of the lubricating oil film. The influences of spindle rotating rate, lubricating oil dynamic viscosity and inlet flow rate on the lubricating oil film dynamic pressure effect of the heavy constant flow hydrostatic center rest were analyzed based on the computational fluid dynamics and lubrication theory, and the influencing laws were revealed. By means of this method, the reasonable data can be provided for reasonably controlling dynamic pressure and structure optimal design of the heavy constant flow hydrostatic center rest.

Study on Dynamic Pressure Effect of Gas Bearings in Fuel Cell Vehicles

2020 ◽  
Author(s):  
Chenxin Zhang ◽  
Weirong Hong ◽  
Shuiying Zheng
Keyword(s):  
Numerical Simulation ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Performance Test ◽  
Pressure Effect ◽  
Dynamic Pressure ◽  
Simulation Method ◽  
Dynamic Mesh ◽  
Gas Bearings ◽  
Cfd Numerical Simulation

Abstract The dynamic pressure effect can contribute to a better working performance of the gas bearing without changing its overall structure or increase its air supply pressure. To study the dynamic pressure effect of gas bearings, a new method of CFD numerical simulation with self-developed UDF dynamic mesh program was proposed. In this way, values of dynamic characteristics for gas bearings with different fluid fields and under different working conditions can be calculated. Based on the numerical simulation results, the influence law of rotational speed, gas film thickness, and radial eccentricity ratio on the dynamic characteristics (load-carrying capacity, stiffness and damping coefficients, static equilibrium position etc.) were obtained. Afterwards, a bearing’s performance test was conducted on a rotor-bearing system in the high-speed air compressor. Compared to the traditional methods, after the dynamic pressure effect was taken into account, the corresponding rotor dynamic calculation of critical speed is more in accordance with the experimental results, thus proved the credibility of the new CFD numerical simulation method with dynamic mesh.

Research on Velocity Field and Dynamic Pressure Effect of Oil Film of Hydrostatic Center Rack

2010 ◽  
Vol 129-131 ◽  
pp. 1119-1123 ◽  
Author(s):  
Jun Peng Shao ◽  
Chao Yin ◽  
Bo Wu ◽  
Zhong Wen Wang ◽  
Zhi Huang ◽  
...  
Keyword(s):  
Velocity Field ◽  
Pressure Field ◽  
Pressure Effect ◽  
Dynamic Pressure ◽  
Spindle Speed ◽  
Engineering Practice ◽  
Element Analysis ◽  
Open Type ◽  
Oil Film ◽  
Simulation Results

Hydrostatic center rack is an open type hydrostatic supporting equipment. In this paper, taking oil film of middle pillow of hydrostatic center rack as the research object, the velocity field, pressure field and dynamic pressure effect are simulated based on CFX finite element analysis software. The velocity distribution, pressure field and the relationship curve between spindle speeds and dynamic pressure are obtained. The simulation results show that there is negative pressure at the entrance of spindle rotation direction. When the spindle speed is less than 360r/min, the dynamic pressure effect is not obvious and at the steady state basically. Above this speed, the dynamic pressure effect increases significantly as the spindle speed rises. The simulation results can reflect the flow law of internal flow field of the middle pillow. It provides a theoretical basis for the structure optimization of hydrostatic center rack and open type radial sliding bearing in engineering practice.

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