Experiments measuring the leakage rate through hole-pattern seals operating at high pressures of up to 8400 kPa reveal the presence of an abrupt variation in the friction factor (up to a factor of three) with change in the pressure difference across the seal. The measured pressure fluctuations suggest that this observation may, perhaps, be understood as a change in fluid instability modes across the cavities of the seal. A more detailed investigation via large eddy simulations (LES) suggest that the switching from shear layer instability mode to a wake instability mode, a phenomenon well known in fundamental studies of cavity flow (without a top bounding wall), is responsible for the observed variation.

References

References
1.
Ha
,
T. W.
,
1992
, “
Rotordynamic Analysis of Annular Honeycomb-Stator Turbulent Gas Seals Using Friction Factor Model Based on Flat Plate Tests
,”
Ph.D. dissertation
, Department of Mechanical Engineering, Texas A&M University, College Station, TX.
2.
San Andres
,
L.
,
2010
, “
Introduction to Bearings and Seals
,”
Class Notes
, Texas A&M University, Last accessed Feb. 10, 2016.
3.
Childs
,
D. W.
, and
Yu
,
Z.
,
1988
, “
A Comparison of Experimental Rotordynamic Coefficients and Leakage Characteristics Between Hole-Pattern Gas Damper Seals and a Honeycomb Seal
,”
ASME J. Eng. Gas Turbines Power
,
120
, pp.
778
783
.
4.
Moody
,
L. F.
,
1944
, “
Friction Factors for Pipe Flow
,”
Trans. ASME
,
66
, pp.
671
684
.
5.
Ha
,
T. W.
,
1989
, “
Friction Factor Data for Flat-Plate Tests of Smooth and Honeycomb Surfaces
,” M.S. thesis, Department of Mechanical Engineering, Texas A&M University, College Station, TX.
6.
Asirvatham
,
D. A.
,
2010
, “
Friction Factor Measurement, Analysis, and Modeling for Flat-Plates With 12.15 mm Diameter Hole-Pattern, Tested With Air at Different Clearances, Inlet Pressures, and Pressure Ratios
,” M.S. thesis, Department of Mechanical Engineering, Texas A&M University, College Station, TX.
7.
Sekaran
,
A.
,
2012
, “
Analysis of Instabilities and Their Impact on Friction-Factor in Hole-Pattern Seals
,”
Ph.D. dissertation
, Department of Mechanical Engineering, Texas A&M University, College Station, TX.
8.
Childs
,
D. W.
,
Kheireddin
,
B.
,
Phillips
,
S.
, and
Asirvatham
,
T. D.
,
2011
, “
Friction Factor Behavior From Flat-Plate Tests of Smooth and Hole-Pattern Roughened Surfaces With Supply Pressures up to 84 Bars
,”
ASME J. Eng. Gas Turbines Power
,
133
(
9
), p.
092504
.
9.
Thomas
,
J.
,
1992
, “
Determination of Variation of Friction Factor With Reynolds Number for Flow Between Two Closely Spaced Rough Plates
,” Senior thesis, Texas A&M University, College Station, TX.
10.
Nava
,
D. L.
,
1993
, “
Observations of Friction Factors for Various Roughness Patterns in Channel Flow
,” M.S. thesis, Department of Mechanical Engineering, Texas A&M University, College Station, TX.
11.
Childs
,
D. W.
, and
Fayolle
,
P.
,
1999
, “
Test Results for Liquid Damper Seals Using a Round-Hole Roughness Pattern for the Stators
,”
ASME J. Tribol.
,
121
(
1
), pp.
42
49
.
12.
Rossiter
,
J. E.
,
1966
, “
Wind-Tunnel Experiments on the Flow Over Rectangular Cavities at Subsonic and Transonic Speeds
,” Aeronautical Research Council, Technical Reports and Memo No. 3438.
13.
Karamacheti
,
K.
,
1955
, “
Acoustic Radiation From Two-Dimensional Rectangular Cutouts in Aerodynamic Surfaces
,” Report No. NACA TM 3478.
14.
Roshko
,
A.
,
1955
, “
Some Measurements of Flow in a Rectangular Cutout
,” NACA Technical Note No. 3488.
15.
Plumblee
,
H. E.
,
Gibson
,
J. S.
, and
Lassiter
,
L. W.
,
1962
, “
A Theoretical and Experimental Investigation of the Acoustic Response of Cavities in an Aerodynamic Flow
,” Wright-Patterson Air Force Base, Dayton, OH, Technical Report No. WADD TR-61-75 (AD-277803).
16.
East
,
L. F.
,
1966
, “
Aerodynamically Induced Resonance in Rectangular Cavities
,”
J. Sound Vib.
,
3
(
3
), pp.
277
287
.
17.
Heller
,
H. H.
, and
Bliss
,
D. B.
,
1975
, “
Aerodynamically Induced Pressure Oscillations in Cavities—Physical Mechanisms and Suppression Concepts
,” Air Force Flight Dynamics Laboratory,
Technical Report No. AFFDL-TR-74-133
.
18.
Rockwell
,
D.
, and
Naudascher
,
E.
,
1978
, “
Review-Self-Sustaining Oscillations of Flow Past Cavities
,”
ASME J. Fluids Eng.
,
100
(
2
), pp.
152
165
.
19.
Sarohia
,
V.
,
1976
, “
Experimental Investigation of Oscillations in Flows Over Shallow Cavities
,”
AIAA
Paper No. 76-182.
20.
Kegerise
,
M. A.
,
Spina
,
E. F.
, and
Cattafesta
,
L. N.
,
1999
, “
An Experimental Investigation of Flow-Induced Cavity Oscillations
,”
AIAA
Paper No. 99-3705.
21.
Zhang
,
X.
,
1995
, “
Compressible Cavity Flow Oscillation Due to Shear Layer Instabilities and Pressure Feedback
,”
AIAA J.
,
33
(
8
), pp.
1404
1411
.
22.
Shieh
,
C. M.
, and
Morris
,
P. J.
,
1999
, “
Parallel Numerical Simulation of Subsonic Cavity Noise
,”
AIAA
Paper No. 99-1891.
23.
Colonius
,
T.
,
Basu
,
A. J.
, and
Rowley
,
C. W.
,
1999
, “
Computation of Sound Generation and Flow/Acoustic Instabilities in the Flow Past an Open Cavity
,”
ASME
Paper No. FEDSM99-7228.
24.
Gloerfelt
,
X.
,
Bailly
,
C.
, and
Juvé
,
D.
,
2001
, “
Computation of the Noise Radiated by a Subsonic Cavity Using Direct Simulation and Acoustic Analogy
,”
AIAA
Paper No. 2001-2226.
25.
Larcheveque
,
L.
,
Sagaut
,
P.
,
Mary
,
I.
,
Labbé
,
O.
, and
Comte
,
P.
,
2003
, “
Large-Eddy Simulation of a Compressible Flow Past a Deep Cavity
,”
Phys. Fluids
,
15
(
1
), pp.
193
210
.
26.
Srinivasan
,
S.
, and
Baysal
,
O.
,
1991
, “
Navier–Stokes Calculations of Transonic Flows Past Cavities
,”
ASME J. Fluids Eng.
,
113
(
3
), pp.
368
376
.
27.
Chang
,
K.
,
Constantinescu
,
G.
, and
Park
,
S.
,
2007
, “
Assessment of Predictive Capabilities of Detached Eddy Simulation to Simulate Flow and Mass Transport Past Open Cavities
,”
ASME J. Fluids Eng.
,
129
(
11
), pp.
1372
1383
.
28.
Suponitsky
,
V.
,
Avital
,
E.
, and
Gaster
,
M.
,
2005
, “
On Three-Dimensionality and Control of Incompressible Cavity Flow
,”
Phys. Fluids
,
17
(
10
), p.
104103
.
29.
Colonius
,
T.
,
2001
, “
An Overview of Simulation, Modeling, and Active Control of Flow/Acoustic Resonance in Open Cavities
,”
AIAA
Paper No. 2001-0076.
30.
Rowley
,
C. W.
,
Colonius
,
T.
, and
Basu
,
A. J.
,
2002
, “
On Self-Sustained Oscillations in Two-Dimensional Compressible Flow Over Rectangular Cavities
,”
J. Fluid Mech.
,
455
, pp.
315
346
.
31.
Rowley
,
C. W.
, and
Williams
,
D. R.
,
2006
, “
Dynamics and Control of High-Reynolds-Number Flow Over Open Cavities
,”
Annu. Rev. Fluid Mech.
,
38
(
1
), pp.
251
276
.
32.
FLUENT, ANSYS
,
2010
, “
Fluent Theory Guide
,”
SAS IP, Inc.
,
Canonsburg, PA
.
33.
Brès
,
G. A.
, and
Colonius
,
T.
,
2008
, “
Three-Dimensional Instabilities in Compressible Flow Over Open Cavities
,”
J. Fluid Mech.
,
599
, pp.
309
339
.
34.
Faure
,
T. M.
,
Adrianos
,
P.
,
Lusseyran
,
F.
, and
Pastur
,
L.
,
2007
, “
Visualizations of the Flow Inside an Open Cavity at Medium Range Reynolds Numbers
,”
Exp. Fluids
,
42
(
2
), pp.
169
184
.
35.
Brès
,
G.
,
2007
, “
Numerical Simulations of Three-Dimensional Instabilities in Cavity Flows
,”
Ph.D. dissertation
, California Institute of Technology, Pasadena, CA.
36.
Liliedahl
,
D. N.
,
Carpenter
,
F. L.
, and
Cizmas
,
P. G. A.
,
2010
, “
Prediction of Aeroacoustic Resonance in Cavities of Hole-Pattern Stator Seals
,”
ASME J. Eng. Gas Turbines Power
,
133
(
2
), p.
022504
.
37.
Lesieur
,
M.
,
Staquet
,
C.
,
Le Roy
,
P.
, and
Comte
,
P.
,
1988
, “
The Mixing Layer and Its Coherence Examined From the Point of View of Two-Dimensional Turbulence
,”
J. Fluid Mech.
,
192
, pp.
511
534
.
38.
Sekaran
,
A.
, and
Morrison
,
G. L.
,
2012
, “
LES Investigations of Instabilities in Cavity Flow With a Top Boundary
,”
65th Annual Meeting of the APS Division of Fluid Dynamics
, San Diego, CA.
39.
Rockwell
,
D.
, and
Knisely
,
C.
,
1979
, “
The Organized Nature of Flow Impingement Upon a Corner
,”
J. Fluid Mech.
,
93
(03), pp.
413
432
.
40.
Coleman
,
H. W.
,
1989
,
Experimentation and Uncertainty Analysis for Engineers
,
Wiley
,
New York
.
41.
Kheireddin
,
B. A.
,
2009
, “
Investigation of the Friction Factor Behavior for Flat Plate Tests of Smooth and Roughened Surfaces With Supply Pressures up to 84 bars
,”
M.S. thesis
, Department of Mechanical Engineering, Texas A&M University, College Station, TX.
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