Time-averaged and phase-averaged size and velocity distributions of water droplets in the turbulent wake of a square cross-section cylinder, measured with a phase-Doppler anemometer, are presented for a Reynolds number ReD=18,500, based on the free stream velocity, U, and cylinder side dimension, D. It is shown that the coherent motion strongly influences the particle distribution and that the mean flow representation can be misleading in interpreting mixing. The results show that small particle concentration is largest in the very near wake. The mean particle distributions are homogeneous as early as 4D downstream of the cylinder, but the influence of vortex shedding on instantaneous distributions persists much longer. It is also observed that at the point of maximum mean streamline curvature, which also coincides with the region of maximum streamwise velocity fluctuations, particle separation is most effective.

1.
Lyn
,
D. A.
,
Einav
,
S.
,
Rodi
,
W.
, and
Park
,
J.-H.
,
1995
, “
A Laser-Doppler Velocimetry Study of Ensemble-Averaged Characteristics of the Turbulent Near Wake of a Square Cylinder
,”
J. Fluid Mech.
,
304
, pp.
285
319
.
2.
Durao, D. F. G., Heitor, M. V., and Pereira, J. C. F., 1986, “A Laser Anemometry Study of Separated Flow Around a Squared Obstacle,” in Laser Anemometry in Fluid Mechanics III (Ed. R. J. Adrian et al.), LADOAN-IST, Lisbon, Portugal.
3.
Wu, K. C. Q., and Martinuzzi, R. J., 1997, “An Experimental Investigation of the Flow Around a Two-Dimensional Square Prism in the Proximity of a Solid Wall: Effect of the Gap Size,” Proc. 11th Symposium on Turb. Shear Flows, Grenoble, France, pp. 1116–1121.
4.
Bearman
,
P. W.
, and
Obasaju
,
E. D.
,
1982
, “
An Experimental Study of Pressure Fluctuations on Fixed and Oscillating Square-Section Cylinders
,”
J. Fluid Mech.
,
119
, pp.
297
321
.
5.
Haidn, O. J., Bailey, S. C. C., and Martinuzzi, R. J., 1999, “Relating Pressure Field and Vortex Shedding Suppression for a Square Cylinder in the Vicinity of a Solid Wall,” Proc. 1st Int. Symposium on Turbulence and Shear Flow Phenomena, Santa Barbara, U.S.A., pp. 1039–1044.
6.
Eaton
,
J. K.
, and
Fessler
,
J. R.
,
1994
, “
Preferential Concentration of Particles by Turbulence
,”
Int. J. Multiphase Flow
,
20
(
Supplement
), pp.
169
209
.
7.
Crowe
,
C. T.
,
Chung
,
J. N.
, and
Troutt
,
T. R.
,
1988
, “
Particle Mixing in Free Shear Flows
,”
Prog. Energy Combust. Sci.
,
14
, pp.
171
194
.
8.
Lazaro
,
B. J.
, and
Lasheras
,
J. C.
,
1989
, “
Particle Dispersion in a Turbulent, Plane, Free Shear Layer
,”
Phys. Fluids A
,
1
, pp.
1035
1044
.
9.
Wen
,
F.
,
Kamalu
,
N.
,
Chung
,
J. N.
,
Crowe
,
C. T.
, and
Troutt
,
T. R.
,
1992
, “
Particle Dispersion by Vortex Structures in Plane Mixing Layers
,”
ASME J. Fluids Eng.
,
114
, pp.
657
666
.
10.
Lazaro
,
B. J.
, and
Lasheras
,
J. C.
,
1992
, “
Particle Dispersion in the Developing Free Shear Layer. Part 1. Unforced Flow
,”
J. Fluid Mech.
,
235
, pp.
143
178
.
11.
Lazaro
,
B. J.
, and
Lasheras
,
J. C.
,
1992
, “
Particle Dispersion in the Developing Free Shear Layer. Part 2. Forced Flow
,”
J. Fluid Mech.
,
235
, pp.
179
221
.
12.
Kiger
,
K. T.
, and
Lasheras
,
J. C.
,
1995
, “
The Effect of Vortex Pairing on Particle Dispersion and Kinetic Energy Transfer in a Two-Phase Turbulent Shear Layer
,”
J. Fluid Mech.
,
302
, pp.
149
178
.
13.
Martin
,
J. E.
, and
Meiburg
,
E.
,
1994
, “
The Accumulation and Dispersion of Heavy Particles in Forced Two-Dimensional Mixing Layers. I. The Fundamental and Subharmonic Cases
,”
Phys. Fluids
,
6
(
3
), pp.
1116
1132
.
14.
Laitone
,
J. A.
,
1981
, “
A Numerical Solution for Gas-Particle Flows at High Reynolds Numbers
,”
J. Appl. Mech.
,
48
, pp.
465
471
.
15.
Chein
,
R.
, and
Chung
,
J. N.
,
1988
, “
Particle Dynamics in a Gas-Particle Flow Over Normal and Inclined Plates
,”
Chem. Eng. Sci.
,
43
(
7
), pp.
1621
1636
.
16.
Tang
,
L.
,
Wen
,
F.
,
Yang
,
Y.
,
Crowe
,
C. T.
,
Chung
,
J. N.
, and
Troutt
,
T. R.
,
1992
, “
Self-Organizing Particle Dispersion Mechanism in a Plane Wake
,”
Phys. Fluids A
,
4
(
10
), pp.
2244
2251
.
17.
Bachalo, W. D., Bachalo, E. J., Hanscom, J., and Sankar, S. V., 1993, “An Investigation of Spray Interaction With Large-Scale Eddies,” Proc. AIAA 31st Aerospace Sciences Meeting, Reno, NV, paper AIAA 93-0696.
18.
Bachalo
,
W. D.
,
1994
, “
Experimental Methods in Multiphase Flows
,”
Int. J. Multiphase Flow
,
20
(
Supplement
), pp.
261
295
.
19.
Crowe
,
C. T.
,
Troutt
,
T. R.
,
Chung
,
J. N.
,
Davis
,
R. W.
, and
Moore
,
E. F.
,
1995
, “
A Turbulent Flow Without Particle Mixing
,”
Aerosol Sci. Technol.
,
22
, pp.
135
138
.
20.
Burns
,
T. J.
,
Davis
,
R. W.
, and
Moore
,
E. F.
,
1999
, “
A Perturbation Study of Particle Dynamics in a Plane Wake Flow
,”
J. Fluid Mech.
,
384
, pp.
1
26
.
21.
Bore´e
,
J.
,
Ishima
,
T.
, and
Flour
,
I.
,
2001
, “
The Effect of Mass Loading and Inter-Particle Collisions on the Development of the Polydispersed Two-Phase Flow Downstream of a Confined Bluff Body
,”
J. Fluid Mech.
,
443
, pp.
129
165
.
22.
Chung
,
J. N.
, and
Troutt
,
T. R.
,
1988
, “
Simulation of Particle Dispersion in an Axisymmetric Jet
,”
J. Fluid Mech.
,
186
, pp.
199
222
.
23.
Longmire
,
E. K.
, and
Eaton
,
J. K.
,
1992
, “
Structure of a Particle-Laden Round Jet
,”
J. Fluid Mech.
,
236
, pp.
217
257
.
24.
Sakakibara
,
J.
,
Wicker
,
R. B.
, and
Eaton
,
J. K.
,
1996
, “
Measurements of the Particle-Fluid Velocity Correlation and the Extra Dissipation in a Round Jet
,”
Int. J. Multiphase Flow
,
22
(
5
), pp.
863
881
.
25.
Raju
,
N.
, and
Meiburg
,
E.
,
1997
, “
Dynamics of Small, Spherical Particles in Vortical and Stagnation Point Flow Fields
,”
Phys. Fluids
,
9
(
2
), pp.
299
314
.
26.
Hussain
,
A. K. M. F.
,
1983
, “
Coherent Structures—Reality and Myths
,”
Phys. Fluids
,
26
(
10
), pp.
2816
2850
.
27.
Saffman
,
M.
,
1987
, “
Automatic Calibration of LDA Measurement Volume Size
,”
Appl. Opt.
,
26
(
13
), pp.
2592
2597
.
28.
Abernethy
,
R. B.
,
Benedict
,
R. P.
, and
Dowdell
,
R. B.
,
1985
, “
ASME Measurement Uncertainty
,”
ASME J. Fluids Eng.
,
107
, pp.
161
164
.
29.
Edwards
,
R. V.
,
1987
, “
Report of the Special Panel on Statistical Particle Bias Problems in Laser Anemometry
,”
ASME J. Fluids Eng.
,
109
, pp.
89
93
.
30.
Benedict
,
L. H.
, and
Gould
,
R. D.
,
1996
, “
Towards Better Uncertainty Estimates for Turbulence Statistics
,”
Exp. Fluids
,
22
, pp.
129
136
.
31.
Saha
,
A. K.
,
Biswas
,
G.
, and
Muralidhar
,
K.
,
2001
, “
Two-Dimensional Study of the Turbulent Wake Behind a Square Cylinder Subject to Uniform Shear
,”
ASME J. Fluids Eng.
,
123
, pp.
595
603
.
You do not currently have access to this content.