An Iterative CFD and Mechanical Brush Seal Model and Comparison With Experimental Results

1999 ◽  
Vol 121 (4) ◽  
pp. 656-662 ◽  
Author(s):  
L. H. Chen ◽  
P. E. Wood ◽  
T. V. Jones ◽  
J. W. Chew
Keyword(s):  
Pressure Distribution ◽  
Mechanical Model ◽  
Experimental Results ◽  
Iterative Technique ◽  
Mechanical Part ◽  
Contact Loads ◽  
Brush Seal ◽  
Mass Flows ◽  
Frictional Effects

The position of the bristles within a brush seal is dictated by the pressure distribution within the seal, which is itself influenced by the position of the bristle matrix. In order to predict mass flows, pressure capabilities, bristle displacements, stresses, and contact loads at the rotor interface, a technique for iterating between a CFD and a mechanical model has been developed. The iterative technique is used to model the behavior of seals with an initial build clearance, where the application of pressure causes a change in the position of the bristle matrix. Frictional effects between neighboring bristles and at the backing ring influence the behavior of the bristles and these are accounted for within the mechanical part of the model. Results are presented and discussed for seals of both initial build clearance and interference. The mathematical predictions for flow, contact loads at the rotor interface, and the nature of the bristles displacements are compared with experimental results.

scholarly journals An Iterative CFD and Mechanical Brush Seal Model and Comparison With Experimental Results

1998 ◽  
Author(s):  
L. H. Chen ◽  
P. E. Wood ◽  
T. V. Jones ◽  
J. W. Chew
Keyword(s):  
Pressure Distribution ◽  
Mechanical Model ◽  
Experimental Results ◽  
Iterative Technique ◽  
Mechanical Part ◽  
Contact Loads ◽  
Brush Seal ◽  
Mass Flows ◽  
Frictional Effects

The position of the bristles within a brush seal is dictated by the pressure distribution within the seal, which is itself influenced by the position of the bristle matrix. In order to predict mass flows, pressure capabilities, bristle displacements, stresses and contact loads at the rotor interface a technique for iterating between a CFD and a mechanical model has been developed. The iterative technique is used to model the behaviour of seals with an initial build clearance, where the application of pressure causes a change in the position of the bristle matrix. Frictional effects between neighbouring bristles and at the backing ring influence the behaviour of the bristles and these are accounted for within the mechanical part of the model. Results are presented and discussed for seals of both initial build clearance and interference. The mathematical predictions for flow, contact loads at the rotor interface and the nature of the bristles displacements are compared with experimental results.

Numerical Analysis of Pressure Distribution in a Brush Seal based on a 2-D Staggered Tube Banks Model

2019 ◽  
pp. -1--1
Author(s):  
Yuchi Kang ◽  
Meihong Liu ◽  
Sharon Kao-Walter ◽  
Jinbin Liu ◽  
Qihong Ceng
Keyword(s):  
Numerical Analysis ◽  
Pressure Distribution ◽  
Brush Seal ◽  
Tube Banks

scholarly journals Brush seal with thermo-regulating bimetal elements

2018 ◽  
Vol 8 (1) ◽  
pp. 307-313 ◽  
Author(s):  
Michał Stanclik
Keyword(s):  
Heat Flux ◽  
Contact Area ◽  
Heat Load ◽  
Experimental Results ◽  
Frictional Heat ◽  
Brush Seal ◽  
Thermoregulatory Function ◽  
Shaft Surface

Abstract This paper presents a new brush seal construction idea. It was shown that it is possible to use bimetallic elements for the construction of the brush seal, which have a thermoregulatory function by relieving a contact area between bristles and a shaft surface reducing frictional heat flux. This should improve the durability of the seal by diminishing the heat load and significantly decreases the temperature of the seal during the startup/ shutdown. This article shows a simplified construction of the concept brush seal as well as numerical and experimental results.

scholarly journals Theoretical Analysis of Brush Seals Leakage Using Local Computational Fluid Dynamics Estimated Permeability Laws

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Lilas Deville ◽  
Mihai Arghir
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Principal Direction ◽  
Experimental Results ◽  
Leakage Flow ◽  
Cfd Analysis ◽  
Brush Seal ◽  
Brush Seals ◽  
Local Reynolds Number

Brush seals are a mature technology that has generated extensive experimental and theoretical work. Theoretical models range from simple correlations with experimental results to advanced numerical approaches coupling the bristles deformation with the flow in the brush. The present work follows this latter path. The bristles of the brush are deformed by the pressure applied by the flow, by the interference with the rotor and with the back plate. The bristles are modeled as linear beams but a nonlinear numerical algorithm deals with the interferences. The brush with its deformed bristles is then considered as an anisotropic porous medium for the leakage flow. Taking into account, the variation of the permeability with the local geometric and flow conditions represents the originality of the present work. The permeability following the principal directions of the bristles is estimated from computational fluid dynamics (CFD) calculations. A representative number of bristles are selected for each principal direction and the CFD analysis domain is delimited by periodicity and symmetry boundary conditions. The parameters of the CFD analysis are the local Reynolds number and the local porosity estimated from the distance between the bristles. The variations of the permeability are thus deduced for each principal direction and for Reynolds numbers and porosities characteristic for brush seal. The leakage flow rates predicted by the present approach are compared with experimental results from the literature. The results depict also the variations of the pressures, of the local Reynolds number, of the permeability, and of the porosity through the entire brush seal.

Pressure Distribution in the Calendering of Plastic Materials

1951 ◽  
Vol 18 (1) ◽  
pp. 101-106
Author(s):  
J. T. Bergen ◽  
G. W. Scott
Keyword(s):  
Pressure Distribution ◽  
Viscous Liquid ◽  
High Speed ◽  
Plastic Material ◽  
The Body ◽  
Experimental Results ◽  
Distribution Characteristics ◽  
Flow Properties ◽  
Pressure Sensitive ◽  
Plastic Materials

Abstract In the calendering, or rolling, of a plastic material in to sheet form by passing it between parallel rolls, hydrostatic pressure is exerted against the surface of the roll throughout the region of contact with the plastic mass. This pressure has been measured by means of a pressure-sensitive cylinder, inserted in the body of a 10-in-diam roll, together with high-speed oscillographic technique. The materials which were calendered consisted of a resin which exhibited flow properties characteristic of a viscous liquid, and several filled plastic compositions of commercial interest. Pressure maxima ranging up to 8000 psi were observed. Comparison of experimental results with theoretical expressions for pressure distribution, as given by several authors, indicates that the equation derived by Gaskell quite satisfactorily predicts the results for the case of the viscous liquid. The commercial plastics were found to exhibit pressure-distribution characteristics which were perceptibly different from those of the viscous liquid. Certain limitations of Gaskell’s treatment of nonviscous materials prevent its application to these experimental results.

Torque Modelling and Experiment in Pelleting Process of Rotated Roll Forming

2012 ◽  
Vol 184-185 ◽  
pp. 609-613
Author(s):  
Kai Wu ◽  
Yu Sun ◽  
Bin Bin Peng
Keyword(s):  
Pressure Distribution ◽  
Powder Material ◽  
Structural Design ◽  
Experimental Results ◽  
Distribution Model ◽  
Roll Forming ◽  
Testing System ◽  
Force Model ◽  
Optimal Structural Design

First the extruding force model of isotropic powder material passing through the die hole in pelleting process was founded, then the pressure distribution model in the extruding areas was built. Based on the two models, the torque model in pelleting process of rotated roll forming was developed. The experiments were carried out on the special designed pellet mill and the wireless torque testing system was used to analysis the torque datum. It is shown the computing datum is very close to the experimental results. The researches are helpful to the optimal structural design, energy consume reduction and proper use of the pellet mill in practice.

Kinematic and Dynamic Determinations of the Movement of the Car when Moving between Cones

2020 ◽  
Vol 896 ◽  
pp. 163-168
Author(s):  
Robert Emil Simniceanu ◽  
Dumitru Neagoe ◽  
Mario Trotea ◽  
Augustin Constantinescu
Keyword(s):  
Mathematical Model ◽  
Mechanical Model ◽  
Experimental Results ◽  
Dynamic Parameters ◽  
Proposed Model ◽  
Theoretical Results

In this paper a mechanical model of the car and the related mathematical model are presented. Based on this mathematical model, some kinematic and dynamic parameters of the car are determined when moving between milestones. These theoretical results are compared with the experimental results to validate the proposed model.

Airflow-Housing-Induced Resonances of Rotating Optical Disks

2007 ◽  
Vol 74 (6) ◽  
pp. 1252-1263 ◽  
Author(s):  
R. M. C. Mestrom ◽  
R. H. B. Fey ◽  
H. Nijmeijer ◽  
P. M. R. Wortelboer ◽  
W. Aerts
Keyword(s):  
Numerical Model ◽  
Pressure Distribution ◽  
Critical Speed ◽  
Experimental Approach ◽  
Experimental Results ◽  
Lubrication Equation ◽  
Global View ◽  
Optical Disks ◽  
Insight Into ◽  
Finite Difference Techniques

Numerous excitation sources for disk vibrations are present in optical drives. For increasing rotation speeds, airflow-housing-induced vibrations have become more and more important. Currently, drives are designed in which rotation speeds are so high that critical speed resonances may show up. The presence of these resonances depends on the layout of the inner housing geometry of the drive. The influence of the drive inner housing geometry is investigated systematically by means of a numerical-experimental approach. An analytical model is derived, containing disk dynamics and the geometry-induced pressure distribution acting as the excitation mechanism on the disk. The Reynolds’ lubrication equation is used as a first approach for the modeling of the pressure distribution. The model is numerically implemented using an approach based on a combination of finite element and finite difference techniques. An idealized, drive-like environment serves as the experimental setup. This setup resembles the situation in the numerical model, in order to be able to verify the numerical model. Wedge-like airflow disturbances are used in order to obtain insight into the influence of drive inner geometry on the critical speed resonances of optical disks. A disk tilt measurement method is designed that yields a global view of the disk deformation. By means of two newly proposed types of plots, numerical and experimental results can be compared in a straightforward way. A qualitative match between the numerical and experimental results is obtained. The numerical and experimental methods presented provide insight into airflow-housing-induced vibrations in optical drives. Additionally, reduction of some critical speed resonances is found to be possible for certain drive inner geometry configurations.

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