This paper presents a new computational fluid dynamics (CFD)/bulk-flow hybrid method to determine the rotordynamic characteristics of annular gas seals. The method utilizes CFD analysis to evaluate the unperturbed base state flow, an averaging method to determine the base state bulk-flow variables, and a bulk-flow perturbation method to solve for the fluid forces acting on an eccentric, whirling rotor. In this study the hybrid method is applied to a hole-pattern seal geometry and compared with experimental data and numerical and analytical methods. The results of this study show that the dynamic coefficients predicted by the hybrid method agree well with the experimental data, producing results that are comparable with a full, three-dimensional, transient, whirling rotor CFD method. Additionally, the leakage rate predicted by the hybrid method is more agreeable with experiment than the other methods. The benefit of the present method is the ability to calculate accurate rotordynamic characteristics of annular seals that are comparable to results produced by full, transient CFD analyses with a simulation time on the order of bulk-flow analyses.

References

References
1.
Hirs
,
G. G.
, 1973, “
A Bulk-Flow Theory for Turbulence in Lubricant Films
,”
J. Lub. Technol.
,
95
(
2
), pp.
137
145
.
2.
Childs
,
D.
, 1993,
Turbomachinery Rotordynamics: Phenomena, Modeling, and Analysis
,
Wiley-Interscience
,
New York
.
3.
Nelson
,
C. C.
, 1984, “
Analysis for Leakage and Rotordynamic Coefficients of Surface-Roughened Tapered Annular Gas Seals
,”
ASME J. Eng. Gas Turbines Power
,
106
(
4
), pp.
927
934
.
4.
Nelson
,
C. C.
, 1985, “
Rotordynamic Coefficients for Compressible Flow in Tapered Annular Seals
,”
ASME J. Tribol.
,
107
(
3
), pp.
318
325
.
5.
Ha
,
T. W.
, and
Childs
,
D. W.
, 1994, “
Annular Honeycomb-Stator Turbulent Gas Seal Analysis Using a New Friction-Factor Model Based on Flat Plate Tests
,”
ASME J. Tribol.
,
116
(
2
), pp.
352
359
.
6.
Kleynhans
,
G. F.
, and
Childs
,
D. W.
, 1997, “
The Acoustic Influence of Cell Depth on the Rotordynamic Characteristics of Smooth-Rotor/Honeycomb-Stator Annular Gas Seals
,”
ASME J. Eng. Gas Turbines Power
,
119
(
4
), pp.
949
956
.
7.
Al-Qutub
,
A. M.
,
Elrod
,
D.
, and
Coleman
,
H. W.
, 2000, “
A New Friction Factor Model and Entrance Loss Coefficient for Honeycomb Annular Gas Seals
,”
ASME J. Tribol.
,
122
(
3
), pp.
622
627
.
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.
Grigoriev
,
B.
,
Schmeid
,
J.
,
Fedorov
,
A.
, and
Lupeleac
,
S.
, 2006, “
Consideration of the Pressure Entrance Loss for the Analysis of Rotordynamic Gas Seals Forces
,” in
Proceedings of the 7th IFToMM-Conference on Rotor Dynamics
.
10.
Arghir
,
M.
,
Billy
,
F.
,
Pineau
,
G.
,
Fr[icirc]ene
,
J.
, and
Texier
,
A.
, 2007, “
Theoretical Analysis of Textured “Damper” Annular Seals
,”
ASME J. Tribol.
,
129
(
3
), pp.
669
678
.
11.
D’Souza
,
R. J.
, and
Childs
,
D.W.
, 2002, “
A Comparison of Rotordynamic-Coefficient Predictions for Annular Honeycomb Gas Seals Using Three Different Friction-Factor Models
,”
ASME J. Tribol.
,
124
(
3
), pp.
524
529
.
12.
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
,” Master’s thesis, Texas A&M University, College Station, TX.
13.
Asirvatham
,
T. D.
, 2010, “
Friction Factor Measurement, Analysis, and Modeling for Flat-Plates With 12.15 mm Diameter Hole-Pattern, Tested With Air at Different Clearances, Inlet Pressure, and Pressure Ratios
,” Master’s thesis, Texas A&M University, College Station, TX.
14.
Dietzen
,
F. J.
, and
Nordmann
,
R.
, 1987, “
Calculating Rotordynamic Coefficients of Seals by Finite-Difference Techniques
,”
ASME J. Tribol.
,
109
(
3
), pp.
388
394
.
15.
Rhode
,
D. L.
,
Hensel
,
S. J.
, and
Guidry
,
M. J.
, 1992, “
Labyrinth Seal Rotordynamic Forces Using a Three-Dimensional Navier-Stokes Code
,”
ASME J. Tribol.
,
114
(
4
), pp.
683
689
.
16.
Athavale
,
M. M.
, and
Hendricks
,
R.
, 1996, “
A Small Perturbation CFD Method for Calculation of Seal Rotordynamic Coefficients
,”
Int. J. Rotating Mach.
,
2
(
3
), pp.
167
177
.
17.
Moore
,
J. J.
, 2003, “
Three-Dimensional CFD Rotordynamic Analysis of Gas Labyrinth Seals
,”
ASME J. Vib. Acoust.
,
125
(
4
), pp.
427
433
.
18.
Untaroiu
,
A.
,
Migliorini
,
P.
,
Wood
,
H. G.
,
Allaire
,
P. E.
, and
Kocur
,
J. A.
, 2009, “
Hole-Pattern Seals: A Three Dimensional CFD Approach for Computing Rotordynamic Coefficient and Leakage Characteristics
,”
ASME Conference Proceedings
, 2009 (
43833
), pp.
981
990
.
19.
Untaroiu
,
A.
,
Dimond
,
T. W.
,
Allaire
,
P. E.
, and
Armentrout
,
R.
, 2009, “
CFD Analysis of a Canned Pump Rotor Considering an Annular Fluid With Axial Flow
,”
ASME Conference Proceedings
, 2009 (
48876
), pp.
1013
1022
.
20.
Chochua
,
G.
, and
Soulas
,
T. A.
, 2007, “
Numerical Modeling of Rotordynamic Coefficients for Deliberately Roughened Stator Gas Annular Seals
,”
ASME J. Tribol.
,
129
(
2
), pp.
424
429
.
21.
Childs
,
D. W.
, and
Wade
,
J.
, 2004, “
Rotordynamic-Coefficient and Leakage Characteristics for Hole-Pattern-Stator Annular Gas Seals—Measurements Versus Predictions
,”
ASME J. Tribol.
,
126
(
2
), pp.
326
333
.
22.
Yan
,
X.
,
Li
,
J.
, and
Feng
,
Z.
, 2011, “
Investigations on the Rotordynamic Characteristics of a Hole-Pattern Seal Using Transient CFD and Periodic Circular Orbit Model
,”
ASME J. Vib. Acoust.
,
133
(
4
), p.
041007
.
23.
Kleynhans
,
G. F.
, 1996, “
A Two-Control-Volume Bulk-Flow Rotordynamics Analysis for Smooth-Rotor/Honeycomb-Stator Gas Annular Seals
,” Ph.D. thesis, Texas A&M University, College Station, TX.
24.
Mathworks, 2011, MATLAB Product Documentation, bvp5c, r2011b ed., Mathworks, Natick, MA.
25.
Wade
,
J. L.
, 2004, “
Test Versus Predictions for Rotordynamic Coefficients and Leakage Rates of Hole-Pattern Gas Seals at Two Clearances in Choked and Unchoked Conditions
,” M.S. thesis, Department of Mechanical Engineering, Texas A&M University.
You do not currently have access to this content.