This paper has experimentally studied the windage torque in a rotor-stator system with superimposed central inflow and rotor-mounted protrusions. A novel measurement method has been proposed, and the basic principle is to transform the torque of rotating components into static torque measured by using a static torquemeter. Compared with the previous research, the difference of the moment coefficient for the free plain disk in this paper is within 10%. The disk models used in the experiments included a plain disk and a rotor with 18 protrusions. Plain-disk results were obtained with axial clearances varying from 4.5 mm to 40.5 mm and a stator of the same diameter. Two test cases were performed: one was the case where the flow structure was dominated by the superimposed flow and the other was where rotation dominated the flow structure. For the plain-disk case, as turbulence parameter increases, the sensitivity of the torque to variations of G value also increases, leaving the moment coefficient as a function of the rotational and throughflow Reynolds number only. Comparing to the flow parameter, gap ratio and shroud-clearance ratio have weaker influence on frictional moment coefficient. The rotor with protrusions results showed that the gap ratio had negligible effect on the moment coefficient for the former case; however, the torque decreased by approximately 20% with the decrease of the gap ratio for the latter case. It was also found that, for different configurations, the deviation in the moment coefficient was attributed to variations in form drag. In addition, the moment coefficient was affected by the orientation of bolts with respect to the direction of rotation. The empirical correlations have been proposed for the windage losses of various bolt configurations, and a further discussion about minimizing the windage losses was conducted.

References

References
1.
Dorfman
,
L. A.
,
1963
,
Hydrodynamic Resistance and the Heat Loss of Rotating Solids
,
Oliver & Boyd
,
Edinburgh
, UK.
2.
Bayley
,
F. J.
, and
Owen
,
J. M.
,
1969
, “
Flow Between a Rotating and a Stationary Disc
,”
Aeronaut. Q.
,
20
, pp.
333
354
.
3.
Von Kármán
,
T.
,
1921
, “
Technical Memorandum on Laminar and Turbulent Friction
,” National Advisory Committee for Aeronautics Report No. 1092.
4.
Daily
,
J. W.
, and
Nece
,
R. E.
,
1960
, “
Chamber Dimension Effects on Induced Flow and Frictional Resistance of Enclosed Rotating Disks
,”
ASME J. Basic Eng.
,
82
, pp.
217
230
.10.1115/1.3662532
5.
Daily
,
J. W.
,
Ernst
,
W. D.
, and
Asbedian
,
V.
,
1964
, “
Enclosed Rotating Disks With Superposed Throughflow
,” MIT, Department of Civil Engineering, Hydrodynamics Laboratory, Cambridge, MA, Report No. 64.
6.
Dibelius
,
G.
,
Radtke
,
F.
, and
Ziemann
,
M.
,
1984
, “
Experiments on Friction, Velocity and Pressure Distribution of Rotating Discs
,” Heat and Mass Transfer in Rotating Machinery, Dubrovnik, Yugoslavia, August 30–September 3, pp.
117
130
.
7.
Zimmermann
,
H.
,
Firsching
,
A.
,
Dibelius
,
G.
, and
Ziemann
,
M.
,
1986
, “
Friction Losses and Flow Distribution for Rotating Disks With Shielded and Protruding Bolts
,”
ASME J. Eng. Gas Turbines Power
,
108
(
3
), pp.
547
552
.10.1115/1.3239945
8.
Owen
,
J. M.
,
1971
, “
The Effect of Forced Flow on Heat Transfer From a Disc Rotating Near a Stator
,”
Int. J. Heat Mass Transfer
,
14
(
8
), pp.
1135
1147
.10.1016/0017-9310(71)90209-2
9.
Owen
,
J. M.
,
1984
, “
Fluid Flow and Heat Transfer in Rotating Disc Systems
,” Heat and Mass Transfer in Rotating Machinery, Dubrovnik, Yugoslavia, August 30–September 3, pp. 81–103.
10.
Chew
,
J. W.
, and
Vaughan
,
C. M.
,
1988
, “
Numerical Predictions for the Flow Induced by an Enclosed Rotating Disc
,” NASA STI/Recon Technical Report No. 88, p. 28281.
11.
Owen
,
J. M.
, and
Rogers
,
R. H.
,
1989
,
Flow and Heat Transfer in Rotating-Disc Systems
,
Research Studies Press
,
Taunton
, UK.
12.
Gartner
,
W.
,
1997
, “
A Prediction Method for the Frictional Torque of a Rotating Disc in a Stationary Housing With Superimposed Radial Outflow
,” ASME Paper No. 97-GT-204.
13.
Owen
,
J. M.
, “
An Approximate Solution for the Flow Between a Rotating and a Stationary Disk
,”
ASME J. Turbomach.
,
111
(
3
), pp.
323
332
.10.1115/1.3262275
14.
Gartner
,
W.
,
1998
, “
A Momentum Integral Method to Predict the Frictional Torque of a Rotating Disc With Protruding Bolts
,” ASME Paper No. 98-GT-138.
15.
Daniels
,
W. A.
,
Johnson
,
B. V.
,
Graber
,
D. J.
, and
Martin
,
R. J.
,
1992
, “
Rim Seal Experiments and Analysis for Turbine Applications
,”
ASME J. Turbomach.
,
114
(
2
), pp.
426
432
.10.1115/1.2929161
16.
Millward
,
J. A.
, and
Robinson
,
P. H.
,
1989
, “
Experimental Investigation Into the Effects of Rotating and Static Bolts on Both Windage Heating and Local Heat Transfer Coefficients in a Rotor-Stator Cavity
,” ASME Paper No. 89-GT-196.
17.
Poncet
,
S.
,
Chauve
,
M.-P.
, and
Schiestel
,
R.
,
2005
, “
Batchelor Versus Stewartson Flow Structures in a Rotor-Stator Cavity With Throughflow
,”
Phys. Fluids
,
17
(
7
), p.
075110
.10.1063/1.1964791
18.
Coren
,
D.
,
Childs
,
P. R. N.
, and
Long
,
C. A.
,
2009
, “
Windage Sources in Smooth-Walled Rotating Disc Systems
,”
Proc. Inst. Mech. Eng. Part C: J. Mech. Eng. Sci.
,
223
(
4
), pp.
873
888
.10.1243/09544062JMES1260
19.
Miles
,
A. L.
,
2012
, “
An Experimental Study of Windage Due to Rotating and Static Bolts in an Enclosed Rotor-Stator System
,” Ph.D. thesis, University of Sussex, Brighton, UK.
20.
Moghaddam
,
E. R.
,
Long
,
C.
, and
Sayma
,
A.
,
2013
, “
A Numerical Investigation of Moment Coefficient and Flow Structure in a Rotor–Stator Cavity With Rotor-Mounted Bolts
,”
Proc. Inst. Mech. Eng. Part A
,
227
(
3
), pp.
306
327
.10.1177/0957650912473543
21.
Long
,
C.
,
Miles
,
A. L.
, and
Coren
,
D.
,
2012
, “
Windage Measurements in a Rotor Stator Cavity With Rotor Mounted Protrusions and Bolts
,”
ASME
Paper No. GT2012-69385.10.1115/GT2012-69385
22.
Schlichting
,
H.
, and
Kestin
,
J.
,
1979
,
Boundary-Layer Theory
,
McGraw-Hill
,
New York
.
You do not currently have access to this content.