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.

Issue Section:
Gas Turbines: Heat Transfer
Topics:
Computational fluid dynamics, Pressure, Stress, Clearances (Engineering), Flow (Dynamics), Rotors, Friction
1.
Braun
M. J.
, and
Kudriavtsev
V. V.
,
1995
, “
A Numerical Simulation of a Brush Seal Section and Some Experimental Results
,”
Journal of Turbomachinery
, Jan., Vol.
117
, pp.
190
–
202
.
2.
Chew
J. W.
,
Lapworth
B. L.
, and
Millener
P. J.
,
1995
, “
Mathematical Modeling of Brush Seals
,”
Int. J. Heat & Fluid Flow
, Vol.
16
, pp.
493
–
500
.
3.
Chupp, R. E., and Holle, G. F., 1994, “Generalising Circular Brush Seal Leakage Through a Randomly Distributed Bristle Bed,” ASME Paper 94-GT-71.
4.
Baylay
F. J.
, and
Long
C. A.
,
1993
, “
A Combined Experimental and Theoretical Study of Flow and Pressure Distribution in a Brush Seal
,”
ASME JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER
, Vol.
115
, No.
2
, pp.
404
–
410
.
5.
Dowler, C. A., Chupp, R. E., and Holle, G. F, 1992, “Simple Effective Thickness Model for Circular Brush Seals,” AIAA-92-3192.
6.
Ferguson, J. G., 1988, “Brushes as High Performance Gas Turbine Seals,” ASME Paper 88-GT-182.
7.
Hendricks, R. C, Griffin, T. A., Kline, T. R., Csavina, K. R., Pancholi, A., and Sood, D., 1994, “Relative Performance Comparison Between Baseline Labyrinth and Dual Brush Compressor Discharge Seals in a T-700 Engine Test,” ASME Paper 94-GT-266.
8.
Turner, M. T., Chew, J. W., and Long, C. A., 1997, “Experimental Investigation and Mathematical Modeling of Clearance Brush Seals,” ASME Paper 97-GT-282.
9.
Wood, P. E., and Jones, T. V., 1997, “A Test Facility for the Measurement of Torques at the Shaft to Seal Interface in Brush Seals,” ASME Paper 97-GT-184.
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