Investigation into Velocity Choice for Determining Aerodynamic Resistance in Brush Seals

2018 ◽  
pp. 616-622
Author(s):  
Yuchi Kang ◽  
Meihong Liu ◽  
Xiangping Hu ◽  
Jinbin Liu
Keyword(s):  
Aerodynamic Resistance ◽  
Brush Seals

scholarly journals Predicting aerodynamic resistance of brush seals using computational fluid dynamics and a 2-D tube banks model

2018 ◽  
Vol 126 ◽  
pp. 9-15 ◽  
Author(s):  
Yuchi Kang ◽  
Meihong Liu ◽  
Sharon Kao-Walter ◽  
Wureguli Reheman ◽  
Jinbin Liu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Aerodynamic Resistance ◽  
Brush Seals ◽  
Tube Banks

Numerical Investigations on the Leakage Flow Characteristics of Brush Seal Based on the Three-Dimensional Staggered Tube Bundle Model

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Dengqian Ma ◽  
Yuanqiao Zhang ◽  
Zhigang Li ◽  
Jun Li ◽  
Xin Yan
Keyword(s):  
Flow Rate ◽  
Tube Bundle ◽  
Aerodynamic Resistance ◽  
Three Dimensional ◽  
Leakage Flow ◽  
Mesh Motion ◽  
Brush Seal ◽  
Leakage Flow Rate ◽  
Structured Mesh ◽  
Brush Seals

Abstract To accurately predict the leakage flow and resistance characteristics of brush seals, the multiblock structured mesh and the mesh motion technique are applied to the three-dimensional (3D) staggered tube bundle model of brush seals. The multiblock structured mesh can easily add nodes and set boundary layers in the interbristle gap between adjacent bristles, which can ensure good mesh quality (orthogonal angle and expansion ratio). The mesh motion technique realizes the overall axial compactness of the bristle pack. The effects of pressure ratio Rp, sealing clearance c, and bristle pack compactness on the leakage flow and resistance characteristics are investigated. To analyze the aerodynamic resistance of the brush seals, Euler number (Eu) is applied in this study. The numerical results are in good agreement with the experimental data. Thus, the accuracy of the presented numerical method is validated. For the contacting brush seal, ΔSx, i has a significant effect on the leakage flow rate reduction. For the clearance brush seal, ΔSx, i has little effect on the leakage flow rate reduction. The leakage flow passing through the sealing clearance keeps almost constant. As for aerodynamic resistance, the presence of the sealing clearance can effectively convert the pressure energy of the leakage flow into the kinetic energy. As a result, the leakage flow velocity exiting the bristle pack of the clearance brush seal is 1.5 to 2.0 times larger than that of the contacting brush seal. Although the existence of the sealing clearance obviously increases the leakage flow rate, it effectively reduces the aerodynamic forces acting on the bristles. The developed numerical approach based on the three-dimensional staggered tube bundle model and multiblock structured mesh can serve as a technical method for analysis of the sealing mechanisms of brush seals.

Aerodynamic resistance of coppiced poplar

2002 ◽  
Vol 114 (1-2) ◽  
pp. 83-102 ◽  
Author(s):  
Robin L Hall
Keyword(s):  
Aerodynamic Resistance

The aerodynamic resistance to a sphere rotating at high Mach numbers in the rarefied transition régime

1966 ◽  
Vol 293 (1433) ◽  
pp. 156-168 ◽  
Keyword(s):  
Experimental Study ◽  
Aerodynamic Resistance ◽  
Pressure Gauge ◽  
Transition Regime ◽  
Drag Torque ◽  
Free Molecule ◽  
Rotating Sphere ◽  
Mach Numbers ◽  
High Mach ◽  
Molecule Flow

An experimental study has been made of the gaseous drag torque on an isolated sphere rotating at high Mach numbers. The sphere was suspended electromagnetically and spun by induction. The drag torque has been measured through the transition régime from continuum to free molecule flow at Mach numbers (based on equatorial speed) of up to about five. These high Mach numbers were achieved in heavy vapours (diiodomethane, germanium tetrabromide and stannic bromide) with sonic speed as little as a quarter of that in air. To measure the pressure in the vapour a second (smaller) rotating sphere was used as a pressure gauge. The results agree well with those previously obtained and show an unexpected Mach number dependence in the transition régime.

Calculation of the primary trajectories of seeds and other particles in strong winds

1983 ◽  
Vol 219 (1215) ◽  
pp. 217-217
Keyword(s):  
Equations Of Motion ◽  
Aerodynamic Resistance ◽  
Reynolds Numbers ◽  
Spherical Particles ◽  
Spores And Pollen ◽  
General Terms ◽  
Wide Range ◽  
Strong Winds ◽  
Dispersal Distances ◽  
Enormous Number

The movement of variously dense spherical particles representing a variety of seeds, fruits, spores and pollen, and released from rest into arbitrary winds and a gravitational field is discussed in general terms that account in detail for changes in the quasi-static aerodynamic resistance to motion experienced by such particles during aerial flight. A hybrid analytical-empirical law is established which describes this resistance fairly accurately for particle Reynolds numbers in the range 0—60 000 and that allows for the numerical integration of the equations of motion so as to cover a very wide range of flight conditions. This makes possible the provision of a set of four-parameter universal range tables from which the dispersal distances for an enormous number of practical cases may be estimated. One particular case of particle movement in a region of pseudo-thermal convection is also discussed and this shows how a marked degree of deposition concentration may be induced in some circumstances by such a flow. Botanists and ecologists concerned with seed and particle dispersal in the environment may find the universal range tables of particular interest and use. This is because the tables obviate the need for the integration of the equations of motion when dealing with individual cases and permit an estimation of range purely on the basis of the specified quantities of particle size, density and altitude of release, atmospheric wind speed, density and viscosity, and the acceleration due to gravity.

scholarly journals Flow Visualization in a Simulated Brush Seal

1990 ◽  
Author(s):  
M. J. Braun ◽  
R. C. Hendricks ◽  
V. Canacci
Keyword(s):  
Flow Visualization ◽  
Flow Fields ◽  
Inlet Pressure ◽  
Complex Flow ◽  
Axial Pressure ◽  
Interface Motion ◽  
Pressure Profiles ◽  
Brush Seal ◽  
Brush Seals

A method to visualize and characterize the complex flow fields in simulated brush seals is presented. The brush seal configuration was tested in a water and then in an oil tunnel. The visualization procedure revealed typical regions that are rivering, jetting, vortical or lateral flows and exist upstream, downstream or within the seal. Such flows are engendered by variations in fiber void that are spatial and temporal and affect changes in seal leakage and stability. While the effects of interface motion for linear or cylindrical configurations have not been considered herein, it is believed that the observed flow fields characterize flow phenomenology in both circular and linear brush seals. The axial pressure profiles upstream, across and downstream of the brush in the oil tunnel have been measured under a variety of inlet pressure conditions and the ensuing pressure maps are presented and discussed.

Aerodynamic Resistance Coefficients of Agricultural Particulates Determined by Elutriation

1973 ◽  
Vol 16 (5) ◽  
pp. 0918-0921 ◽  
Author(s):  
S. Edward Law ◽  
John A. Collier
Keyword(s):  
Aerodynamic Resistance ◽  
Resistance Coefficients
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