This experimental study concerns the characteristics of vortex flow in a concentric annulus with a diameter ratio of 0.52, whose outer cylinder is stationary and inner one is rotating. Pressure losses and skin friction coefficients have been measured for fully developed laminar flows of water and of 0.4% aqueous solution of sodium carboxymethyl cellulose, respectively, when the inner cylinder rotates at the speed of $0-600rpm$. The results of the present study show the effect of the bulk flow Reynolds number Re and Rossby number Ro on the skin friction coefficients. They also point to the existence of a flow instability mechanism. The effect of rotation on the skin friction coefficient depends significantly on the flow regime. In all flow regimes, the skin friction coefficient is increased by the inner cylinder rotation. The change in skin friction coefficient, which corresponds to a variation of the rotational speed, is large for the laminar flow regime, whereas it becomes smaller as Re increases for transitional flow regime and, then, it gradually approaches to zero for turbulent flow regime. Consequently, the critical bulk flow Reynolds number $Rec$ decreases as the rotational speed increases. The rotation of the inner cylinder promotes the onset of transition due to the excitation of Taylor vortices.

1.
Taylor
,
G. I.
, 1923, “
Stability of a Viscous Fluid Contained Between Two Rotating Cylinders
,”
Philos. Trans. R. Soc. London, Ser. A
0962-8428,
223
, pp.
289
343
.
2.
Diprima
,
R. C.
1960, “
The Stability of a Viscous Fluid Between Rotating Cylinders With a Bulk Flow
,”
J. Fluid Mech.
0022-1120,
366
, pp.
621
631
.
3.
Watanabe
,
S.
, and
,
Y.
, 1973, “
Frictional Moment and Pressure Drop of the Flow Through Co-Axial Cylinders With an Outer Rotating Cylinder
,”
Bull. JSME
0021-3764,
16
(
93
), pp.
551
559
.
4.
Nouri
,
J. M.
, and
Whitelaw
,
J. H.
, 1994, “
Flow of Newtonian and Non-Newtonian Fluids in a Concentric Annulus With Rotation of the Inner Cylinder
,”
ASME J. Fluids Eng.
0098-2202,
116
, pp.
821
827
.
5.
Escudier
,
M. P.
, and
Gouldson
,
I. W.
, 1995, “
Concentric Annular Flow With Centerbody Rotation of a Newtonian and a Shear-Thinning Liquid
,”
Int. J. Heat Fluid Flow
0142-727X,
16
, pp.
156
162
.
6.
Delwiche
,
R. A.
,
Lejeune
,
M. W. D.
, and
Stratabit
,
D. B.
, 1992, “
Slimhole Drilling Hydraulics
,” SPE Paper No. 24596, pp. 521–541.
7.
Siginer
,
D. A.
, and
Bakhtiyarov
,
S. I.
, 1998, “
Flow of Drilling Fluids in Eccentric Annuli
,”
J. Non-Newtonian Fluid Mech.
0377-0257,
78
, pp.
119
132
.
8.
Escudier
,
M. P.
,
Oliveira
,
P. J.
, and
Pinho
,
F. T.
, 2002, “
Fully Developed Laminar Flow of Purely Viscous Non-Newtonian Liquids Through Annuli, Including the Effects of Eccentricity and Inner-Cylinder Rotation
,”
Int. J. Heat Fluid Flow
0142-727X,
23
, pp.
52
73
.
9.
Bird
,
R. B.
,
Lightfoot
,
E. N.
, and
Stewart
,
W. E.
, 1960,
Transport Phenomena
, pp.
34
70
.
10.
,
Y.
, and
Watanabe
,
S.
, 1973, “
Frictional Moment and Pressure Drop of the Flow Through Co-Axial Cylinders With an Outer Rotating Cylinder
,”
Bull. JSME
0021-3764,
12
(
93
), pp.
551
559
.
11.
Shah
,
R. K.
, and
London
,
A. L.
, 1978,
Laminar Flow Forced Convection
,
, New York.
12.
Wereley
,
S. T.
, and
Lueptow
,
R. M.
, 1998, “
Spatio-Temporal Character of Non-Wavy and Wavy Taylor-Couette Flow
,”
J. Fluid Mech.
0022-1120,
364
, pp.
59
80
.