Developments in brush seal analyses tools have been covering advanced flow and structural analyses since brush seals are applied at elevated pressure loads, temperatures, surface speeds, and transients. Brush seals have dynamic flow and structural behaviors that need to be investigated in detail in order to estimate final leakage output and service life. Bristles move, bend, and form a grift matrix depending on pressure load. The level of pressure load determines the tightness of the bristle pack, and thus, the leakage. In the computational fluid dynamics (CFD) analyses of this work, the bristle pack is treated as a porous medium. Based on brush seal test data, the flow resistance coefficients (FRC) for the porous bristle pack are calibrated as a function of pressure load. A circular seal is tested in a static test rig under various pressure loads at room temperature. The FRC calibration is based on test leakage and literature-based axial pressure distribution on the rotor surface and radial pressure distribution over the backing plate. The anisotropic FRC are treated as spatial dependent in axisymmetrical coordinates. The fence height region and the upper region of bristle pack have different FRC since the upper region is supported by backing plate, while bristles are free to move and bend at the fence height region. The FRC are found to be almost linearly dependent on the pressure load for investigated conditions. The blow-down is also calculated by incorporating test leakage and calibrated FRC.

References

1.
Duran
,
E. T.
,
Aksit
,
M. F.
, and
Ozmusul
,
M.
,
2016
, “
Brush Seal Structural Analysis and Correlation With Tests for Turbine Conditions
,”
ASME J. Eng. Gas Turbines Power
,
138
(
5
), p.
052502
.
2.
Lelli
,
D.
,
Chew
,
J. W.
, and
Cooper
,
P.
,
2006
, “
Combined Three-Dimensional Fluid Dynamics and Mechanical Modeling of Brush Seals
,”
ASME J. Turbomach.
,
128
(
1
), pp.
188
195
.
3.
Huang
,
S.
,
Suo
,
S.
,
Li
,
Y.
, and
Wang
,
Y.
,
2014
, “
Theoretical and Experimental Investigation on Tip Forces and Temperature Distributions of the Brush Seal Coupled Aerodynamic Force
,”
ASME J. Eng. Gas Turbines Power
,
136
(
5
), p.
052502
.
4.
Sun
,
D.
,
Liu
,
N.-N.
,
Fei
,
C.-W.
,
Hu
,
G.-Y.
,
Ai
,
Y.-T.
, and
Choy
,
Y.-S.
,
2016
, “
Theoretical and Numerical Investigation on the Leakage Characteristics of Brush Seals Based on Fluid-Structure Interaction
,”
Aerosp. Sci. Technol.
,
58
, pp.
207
216
.
5.
Dogu
,
Y.
,
2005
, “
Investigation of Brush Seal Flow Characteristics Using Bulk Porous Medium Approach
,”
ASME J. Eng. Gas Turbines Power
,
127
(
1
), pp.
136
144
.
6.
Bayley
,
F. J.
, and
Long
,
C. A.
,
1993
, “
A Combined Experimental and Theoretical Study of Flow and Pressure Distributions in a Brush Seal
,”
ASME J. Eng. Gas Turbines Power
,
115
(
2
), pp.
404
410
.
7.
Turner
,
M. T.
,
Chew
,
J. W.
, and
Long
,
C. A.
,
1998
, “
Experimental Investigation and Mathematical Modelling of Clearance Brush Seals
,”
ASME J. Eng. Gas Turbines Power
,
120
(
3
), pp.
573
579
.
8.
Chen
,
L. H.
,
Wood
,
P. E.
,
Jones
,
T. V.
, and
Chew
,
J. W.
,
2000
, “
Detailed Experimental Studies of Flow in Large Scale Brush Seal Model and a Comparison With CFD Predictions
,”
ASME J. Eng. Gas Turbines Power
,
122
(
4
), pp.
672
679
.
9.
Chew
,
J. W.
,
Lapworth
,
B. L.
, and
Millener
,
P. J.
,
1995
, “
Mathematical Modelling of Brush Seals
,”
Int. J. Heat Fluid Flow
,
16
(
6
), pp.
494
500
.
10.
Dogu
,
Y.
, and
Aksit
,
M. F.
,
2006
, “
Effects of Geometry on Brush Seal Pressure and Flow Fields—Part I: Front Plate Configurations
,”
ASME J. Turbomach.
,
128
(
2
), pp.
367
378
.
11.
Dogu
,
Y.
, and
Aksit
,
M. F.
,
2006
, “
Effects of Geometry on Brush Seal Pressure and Flow Fields—Part II: Backing Plate Configurations
,”
ASME J. Turbomach.
,
128
(
2
), pp.
379
389
.
12.
Dogu
,
Y.
, and
Aksit
,
M. F.
,
2006
, “
Brush Seal Temperature Distribution Analysis
,”
ASME J. Eng. Gas Turbines Power
,
128
(
3
), pp.
599
609
.
13.
Dogu
,
Y.
,
Aksit
,
M. F.
,
Demiroglu
,
M.
, and
Dinc
,
O. S.
,
2008
, “
Evaluation of Flow Behavior for Clearance Brush Seals
,”
ASME J. Eng. Gas Turbines Power
,
130
(
1
), p.
012507
.
14.
Pugachev
,
A. O.
, and
Helm
,
P.
,
2009
, “
Calibration of Porous Medium Models for Brush Seals
,”
Proc. Inst. Mech. Eng., Part A
,
223
(
1
), pp.
83
91
.
15.
Qiu
,
B.
, and
Li
,
J.
,
2013
, “
Numerical Investigations on the Heat Transfer Behavior of Brush Seals Using Combined Computational Fluid Dynamics and Finite Element Method
,”
ASME J. Heat Transfer
,
135
(
12
), p.
122601
.
16.
Dogu
,
Y.
,
Bahar
,
A. S.
,
Sertçakan
,
M. C.
,
Pişkin
,
A.
,
Arıcan
,
E.
, and
Kocagül
,
M.
,
2015
, “
Computational Fluid Dynamics Investigation of Brush Seal Leakage Performance Depending on Geometric Dimensions and Operating Conditions
,”
ASME J. Eng. Gas Turbines Power
,
138
(
3
), p.
032506
.
17.
Moffat
,
R. J.
,
1988
, “
Describing the Uncertainties in Experimental Results
,”
Exp. Therm. Fluid Sci.
,
1
(
1
), pp.
3
17
.
18.
ANSYS
,
2013
, “ANSYS Fluent User's Guide, Release 15.0,” ANSYS, Canonsburg, PA.
19.
Baker
,
J. E.
,
2008
, “Measurements of Leakage, Power Loss and Rotordynamic Force in a Hybrid Brush Seal,”
M.Sc. thesis
, Texas A&M University, College Station, TX.http://oaktrust.library.tamu.edu/bitstream/handle/1969.1/ETD-TAMU-2767/BAKER-THESIS.pdf
20.
Crudgington
,
P. F.
, and
Bowsher
,
A.
,
2003
, “Brush Seal Blow Down,”
AIAA
Paper No. 2003-4697.
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