Hydrodynamic Analysis of the Flow in a Rotary Lip Seal Using Flow Factors

2004 ◽  
Vol 126 (1) ◽  
pp. 156-161 ◽  
Author(s):  
Richard F. Salant ◽  
Ann H. Rocke

The flow field in the lubricating film of a rotary lip seal is analyzed numerically by solving the Reynolds equation with flow factors. The behavior of such a flow field is dominated by the asperities on the lip surface. Since previous analyses treated those asperities deterministically, they required very large computation times. The present approach is much less computationally intensive because the asperities are treated statistically. Since cavitation and asperity orientation play important roles, these are taken into account in the computation of the flow factors. Results of the analysis show how the operating parameters of the seal and the characteristics of the asperities affect such seal characteristics as the pressure distribution in the film, the pumping rate and the load support.

1994 ◽  
Vol 116 (1) ◽  
pp. 56-62 ◽  
Author(s):  
R. F. Salant ◽  
A. L. Flaherty

An elastohydrodynamic analysis of a rotary lip seal containing microundulations, incorporating both the fluid mechanics of the lubricating film and the elastic behavior of the lip, has been performed numerically. The results indicate that, under dynamic conditions, the undulation pattern deforms such that it produces reverse pumping. The reverse pumping rate is substantial, and overwhelms the natural leakage induced by the sealed pressure, thereby preventing leakage through the seal. The results also show that the undulations hydrodynamically generate sufficiently high pressures, within the film, to provide load support and maintain the integrity of the film.


1992 ◽  
Vol 114 (3) ◽  
pp. 485-491 ◽  
Author(s):  
R. F. Salant

The flow field within the lubricating film of a rotating shaft lip seal containing microundulations is analyzed numerically. The results demonstrate that the action of the microundulations can prevent leakage through the seal. The effects on leakage rate of shaft speed, undulation amplitude and wavelength, shear deformation of the undulations, flattening of the undulations, and axial lip profile are presented.


2013 ◽  
Vol 650 ◽  
pp. 506-512
Author(s):  
Xiang Zhao ◽  
Bo Liu ◽  
Jun An Zhang

This paper adopts the Reynolds equation as the governing equation of gas lubrication; it mainly focuses on the complex flow field of flotation cushion with multiple supply-holes and analyzes the gas pressure distribution of bias load on the integral flotation cushion by the numerical method. At the same time, according to the mass conservation principle, an efficient revision iteration route about outlet pressure boundary condition of each supply-hole has been set, and the pressure distribution and flow rate of each supply-hole at different declination are calculated. The results show that when the flotation cushion deflection angle varies, due to the edge deflation, the outlet pressure of the orifice is not in strict inverse proportion to the thickness of gas film on the orifice on the integral flotation cushion.


2014 ◽  
Vol 709 ◽  
pp. 196-199
Author(s):  
Qiong Zhou ◽  
Zheng Mei Li ◽  
Yan Wu

Lip seal, widely used in industries, is usually applied to seal pressure chamber. Leakage of lip seal has always been a primary problem. In the present study, hydrodynamic property of lubricating film and elastic deformation of sealing lip are analyzed numerically by coupling Reynolds equation and elastic deformation equation. A numerical model for calculating leakage is proposed, results of the analysis will be of help to interference design and structure optimization for auto water pump bearing’s seal.


1999 ◽  
Vol 121 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Kevin Day ◽  
Richard F. Salant

A numerical thermal elastohydrodynamic model of a radial lip seal, with a flooded air side, has been constructed. The shaft surface is modeled as perfectly smooth, while the lip microgeometry is modeled as a uniform distribution of asperities with initially circular cross-sections. The asperities can deform circumferentially as the bulk lip material shears. Both the viscosity of the fluid and the elastic modulus of the lip are temperature dependent. Model predictions include the pressure distribution in the lubricating film under the lip, the film thickness distribution, the cavitation distribution, the pumping rate, and the lip temperature distribution.


2010 ◽  
Vol 156-157 ◽  
pp. 948-955
Author(s):  
Guang Yao Meng ◽  
Ji Wen Tan ◽  
Yi Cui

Relative motion between grinding wheel and workpiece makes the lubricant film pressure formed by grinding fluid in the grinding area increase, consequently, dynamic pressure lubrication forms. The grinding fluid flow field mathematical model in smooth grinding area is established based on lubrication theory. The dynamic pressure of grinding fluid field, flow velocity and carrying capacity of lubricating film are calculated by the numerical analysis method. An analysis of effect of grinding fluid hydrodynamic on the total lifting force is performed, and the results are obtained.


1992 ◽  
Vol 114 (3) ◽  
pp. 553-560 ◽  
Author(s):  
O. Le´onard ◽  
R. A. Van den Braembussche

A iterative procedure for blade design, using a time marching procedure to solve the unsteady Euler equations in the blade-to-blade plane, is presented. A flow solver, which performs the analysis of the flow field for a given geometry, is transformed into a design method. This is done by replacing the classical slip condition (no normal velocity component) by other boundary conditions, in such a way that the required pressure or Mach number distribution may be imposed directly on the blade. The unknowns are calculated on the blade wall using the so-called compatibility relations. Since the blade shape is not compatible with the required pressure distribution, a nonzero velocity component normal to the blade wall evolves from the new flow calculation. The blade geometry is then modified by resetting the wall parallel to the new flow field, using a transpiration technique, and the procedure is repeated until the calculated pressure distribution has converged to the required one. Examples for both subsonic and transonic flows are presented and show a rapid convergence to the geometry required for the desired Mach number distribution. An important advantage of the present method is the possibility to use the same code for the design and the analysis of a blade.


2019 ◽  
Vol 8 (2S3) ◽  
pp. 1000-1003 ◽  

In this paper, a study on the effect of the control on the wall pressure as well as the quality of the flow when tiny jets were employed. The small jet aimed to regulate the base pressure at the base region of the suddenly expanded duct and wall pressure distribution is carried out experimentally. The convergent-divergent (CD) nozzle with a suddenly expanded duct was designed to observe the wall pressure distribution with and without control using small jets. In order to obtain the results with the effect of controlled four tiny jets of 1 mm diameter located at a ninety-degree interval along a pitch circle diameter (PCD) of 1.3 times the CD nozzle exit diameter in the base, region was employed as active controls. The Mach numbers of the rapidly expanded are 1.5. The jets were expanded quickly into an axis-symmetry duct with an area ratio of 4.84. The length-todiameter (L/D) ratio of the rapid expansion duct was diverse from 10 to 1. There is no adverse effect due to the presence of the tiny jets on the flow field as well as the quality of the flow in the duct


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