Turbomachinery flows can be extremely difficult to predict, due to a multitude of effects, including interacting strain rates, compressibility, and rotation. The primary objective of this investigation was to study the influence of multiple strain rates (favorable streamwise pressure gradient combined with radial pressure gradient due to convex curvature) on the structure of the turbulent boundary layer. The emphasis was on the initial region of curvature, which is relevant to the leading edge of a stator vane, for example. In order to gain better insight into the dynamics of complex turbulent boundary layers, detailed velocity measurements were made in a low-speed water tunnel using a two-component laser Doppler velocimeter. The mean and fluctuating velocity profiles showed that the influence of the strong favorable pressure augmented the stabilizing effects of convex curvature. The trends exhibited by the primary Reynolds shear stress followed those of the mean turbulent bursting frequency, i.e., a decrease in the bursting frequency coincided with a reduction of the peak Reynolds shear stress. It was found that the effects of these two strain rates were not superposable, or additive in any simple manner. Thus, the dynamics of the large energy-containing eddies and their interaction with the turbulence production mechanisms must be considered for modeling turbulent flows with multiple strain rates.

1.
P. R.
, and
Ahmed
A.
,
1993
, “
Turbulent Boundary Layers Subjected to Multiple Curvatures and Pressure Gradients
,”
Journal of Fluid Mechanics
, Vol.
246
, pp.
503
527
.
2.
Barlow
R. S.
, and
Johnston
J. P.
,
1988
a, “
Structure of Turbulent Boundary Layers on a Concave Surface
.”
Journal of Fluid Mechanics
, Vol.
191
, pp.
137
176
.
3.
Barlow
R. S.
, and
Johnston
J. P.
,
1988
b, “
Local Effects of Large-Scale Eddies on Bursting in a Concave Boundary Layer
,”
Journal of Fluid Mechanics
, Vol.
191
, pp.
177
195
.
4.
V.
,
Pontikis
V. G.
, and
P.
,
1990
, “
Experimental Investigation of Three-Dimensional Turbulent Boundary Layers on Infinite Swept Curved Wings
,”
Journal of Fluid Mechanics
, Vol.
211
, pp.
95
122
.
5.
V.
,
Smits
A. J.
, and
Joubert
P. N.
,
1991
, “
A Turbulent Flow Over a Curved Hill. Part 2
,”
Journal of Fluid Mechanics
, Vol.
232
, pp.
377
402
.
6.
Bogard
D. G.
, and
Tiederman
W. G.
,
1986
, “
Burst Detection with Single-Point Velocity Measurements
,”
Journal of Fluid Mechanics
, Vol.
162
, pp.
389
413
.
7.
Gibson, M. M., 1988, “Effects of Surface Curvature on the Law of the Wall,” Near-Wall Turbulence, 1988 Zoran Zaric Memorial Conference, S. J. Kline and N. H. Afgan, eds., Hemisphere.
8.
Gibson
M. M.
,
Verriopoulos
C. A.
, and
Vlachos
N. S.
,
1984
, “
Turbulent Boundary Layer Flow on a Mildly Curved Convex Surface
,”
Experiments in Fluids
, Vol.
2
, pp.
17
24
.
9.
Gillis
J. C.
, and
Johnston
J. P.
,
1983
, “
Turbulent Boundary Layer Flow and Structure on a Convex Wall and its Redevelopment on a Flat Wall
,”
Journal of Fluid Mechanics
, Vol.
135
, pp.
123
153
.
10.
Kline, S. J., and McClintock, F. A., 1953, “Describing Uncertainties in Single Sample Experiments,” Mech. Eng., p. 3.
11.
Kline
S. J.
,
Reynolds
W. C.
,
Schraub
F. A.
, and
P. W.
,
1967
, “
The Structure of Turbulent Boundary Layers
,”
Journal of Fluid Mechanics
, Vol.
30
, Part 4, pp.
741
773
.
12.
Lu
S. S.
, and
Willmarth
W. W.
,
1973
, “
Measurements of the Reynolds Stress in a Turbulent Boundary Layer
,”
Journal of Fluid Mechanic
, Vol.
60
, pp.
481
511
.
13.
McLaughlin
D. K.
, and
Tiederman
W. G.
,
1973
, “
Biasing Correction for Individual Realization of Laser Velocimeter Measurements in Turbulent Flows
,”
Physics of Fluids
, Vol.
16
, pp.
2082
2088
.
14.
Moffat
R. J.
,
1988
, “
Describing the Uncertainties in Experimental Results
,”
Exp. Thermal Fluid Sci.
, Vol.
3
, p.
3
3
.
15.
Nagano, Y., Tagawa, M., and Tsuji, T., 1991, “Effects of Adverse Pressure Gradients on Mean Flows and Turbulence Statistics in a Boundary Layer,” 8th Symposium on Turbulent Shear Flows, University of Munich, pp. 2–3–1 to 2–3–6.
16.
Narasimha
R.
, and
Sreenivasan
K. R.
,
1979
, “
Relaminarization of Fluid Flows
,”
Advances in Applied Mechanics
, Vol.
19
, Indian Institute of Science, Bangalore, India, pp.
221
309
.
17.
Savill
A. M.
,
1987
, “
Recent Developments in Rapid-Distortion Theory
,”
Annual Review Fluid Mechanics
, Vol.
19
, pp.
531
575
.
18.
Schwarz
A. C.
, and
Plesniak
M. W.
,
1996
a, “
The Influence of Interacting Strain Rates on Turbulence in Convex Boundary Layers
,”
Physics of Fluids
, Vol.
8
, pp.
3163
3171
.
19.
Schwarz
A. C.
, and
Plesniak
M. W.
,
1996
b, “
Convex Turbulent Boundary Layers with Zero and Favorable Pressure Gradients
,”
ASME JOURNAL OF FLUIDS ENGINEERING
, Vol.
118
, pp.
787
794
.
20.
Schwarz, A. C., 1998, “Response of a Turbulent Boundary Layer to Multiple Strain Rates,” Ph.D. thesis, Purdue University, West Lafayette, IN.
21.
So
R. M. C.
, and
Mellor
G. L.
,
1973
, “
Experimental on convex curvature effects in turbulent boundary layers
,”
Journal of Fluid Mechanics
, Vol.
60
, Part 1, pp.
43
62
.
22.
Spalart
P. R.
,
1988
, “
Direct Simulation of a Turbulent Boundary Layer up to Reθ = 1410
,”
Journal of Fluid Mechanics
, Vol.
187
, pp.
61
98
.
23.
Spalart
P. R.
, and
Shur
M.
,
1997
, “
On the Sensitization of Turbulence Models to Rotation and Curvature
,”
Aerospace Science and Technology
, Vol.
1
, No.
5
, pp.
297
302
.
24.
Townsend
A. A.
,
1980
, “
The Response of Sheared Turbulence to Additional Distortion
,”
Journal of Fluid Mechanics
, Vol.
98
, pp.
171
191
.
25.
Walker, D. T., and Tiederman, W. G., 1988, “Turbulence Structure and Mass Transport in a Channel Flow with Polymer Injection,” Report PME-FM-88–2, Purdue University, W. Lafayette, IN.
26.
Webster
D. R.
,
Degraaff
D. B.
, and
Eaton
J. K.
,
1996
, “
Turbulence Characteristics of a Boundary Layer Over a Two-Dimensional Bump
,”
Journal of Fluid Mechanics
, Vol.
320
, pp.
53
69
.
27.
White, J. B., and Tiederman, W. G., 1990, “The Effect of Adverse Pressure Gradient on the Turbulent Burst Structure in Low-Reynolds Number Equilibrium Boundary Layers,” Proceedings of the 12th Symposium on Turbulence, University of Missouri-Rolla, Rolla, MO, pp. A5.1–A5.8.
28.
Yanta, W. J., and Smith, R. J., 1973, “Measurements of Turbulence Transport Properties with a Laser Doppler Velocimeter,” AIAA Paper No. 73-169.
This content is only available via PDF.
You do not currently have access to this content.