Abstract

Experimental measurements using a laser Doppler anemometer (LDA) system have been performed on 150μm dense glass particles in a fully developed downward channel flow in air. Tests were conducted in smooth, rough development, and fully rough wall conditions with a channel Reynolds number of 13,800, corresponding to a centerline gas phase velocity of 10.5ms with a dilute loading of particles of 15% by mass fraction. Velocities were measured and statistics compared to see the nature of the effects of the wall roughness in a rebuilt channel facility originally used for important works including Kulick, Fessler, and Eaton, (1994, “Particle Response and Turbulence Modification in Fully-Developed Channel flow,” J. Fluid Mech., 277, pp. 109–134) and Paris (2001, “Turbulence Attenuation in a Particle-Laden Channel Flow,” Ph.D. thesis, Stanford University, Stanford, CA). Wall roughness has a substantial impact on gas phase mean velocities across most of the channel width, except very near the wall. The turbulence intensity of the gas phase is enhanced across the entire channel in the presence of fully rough walls. The rough walls have an even greater impact on the particle phase. Streamwise particle velocities are reduced up to 40%, and become quite uniform across the channel. Particle fluctuating velocities are nearly doubled near the channel centerplane. Profiles appear uniform, due in large part to strong transverse mixing induced by particle-wall collisions. Much of the data of Kulick and Paris is shown here to be strongly influenced by wall conditions with poorly defined roughness in the development region, followed by rapid flow recovery in a relatively smooth test section.

1.
Kulick
,
J. D.
,
Fessler
,
J. R.
, and
Eaton
,
J. K.
, 1994, “
Particle Response and Turbulence Modification in Fully-Developed Channel Flow
,”
J. Fluid Mech.
0022-1120,
277
, pp.
109
134
.
2.
Paris
,
A. D.
, 2001, “
Turbulence Attenuation in a Particle-Laden Channel Flow
,” Ph.D. thesis, Stanford University, Stanford, California.
3.
Caraman
,
N.
,
Boree
,
J.
, and
Simonin
,
O.
, 2003, “
Effect of Collisions on the Dispersed Phase Fluctuation in a Dilute Tube Flow; Experimental and Theoretical Analysis
,”
Phys. Fluids
1070-6631,
15
, pp.
3602
3612
.
4.
Fukagata
,
K.
,
Zahrai
,
S.
,
Kondo
,
S.
, and
Bark
,
F.
, 2001, “
Anomalous Velocity Fluctuations in Particulate Turbulent Channel Flow
,”
Int. J. Multiphase Flow
0301-9322,
27
, pp.
701
719
.
5.
Rouson
,
D.
, 1997, “
A Direct Numerical Simulation of a Particle-laden Turbulent Channel Flow
,” Ph.D. thesis, Stanford University, Stanford, CA;
also available as
Rouson
,
D. W. I.
,
Abrahamson
,
S. D.
, and
Eaton
,
J. K.
, Report No. TSD-101, Mechanical Engineering Department,
Stanford University
.
6.
Wang
,
Q.
, and
Squires
,
K.
, 1996, “
Large Eddy Simulation of Particle-Laden Turbulent Channel Flow
,”
Phys. Fluids
1070-6631,
8
, pp.
1207
1223
.
7.
Yamamoto
,
Y.
,
Potthoff
,
M.
,
Tanaka
,
T.
,
Kajishima
,
T.
, and
Tsuji
,
Y.
, 2001, “
Large-Eddy Simulation of Turbulent Gas-particle Flow in a Vertical Channel: Effect of considering Inter-Particle Collisions
,”
J. Fluid Mech.
0022-1120,
442
, pp.
303
334
.
8.
Perry
,
A. E.
,
Schofield
,
W. H.
, and
Joubert
,
P. N.
, 1969, “
Rough-Wall Turbulent Boundary Layers
,”
J. Fluid Mech.
0022-1120,
37
, pp.
383
413
.
9.
Perry
,
A. E.
,
Lim
,
K. L.
, and
Henbest
,
S. M.
, 1987, “
An Experimental Study of the Turbulence Structure is Smooth and Rough-Wall Boundary Layers
,”
J. Fluid Mech.
0022-1120,
177
, pp.
437
466
.
10.
Raupach
,
M. R.
,
Antonia
,
R. A.
, and
Rajagopalan
,
S.
, 1991, “
Rough-wall Turbulent Boundary Layers
,”
Appl. Mech. Rev.
0003-6900,
37
, pp.
383
413
.
11.
Krogstad
,
P. A.
,
Antonia
,
R. A.
, and
Browne
,
L. W. B.
, 1992, “
Comparisons Between Rough and Smooth Wall Turbulent Boundary Layers
,”
J. Fluid Mech.
0022-1120,
245
, pp.
599
617
.
12.
Kussin
,
J.
, and
Sommerfeld
,
M.
, 2002, “
Experimental Studies on Particle Behaviour and Turbulence Modification in Horizontal Channel with Different Wall Roughness
,”
Exp. Fluids
0723-4864,
33
, pp.
143
159
.
13.
Tanaka
,
M.
,
Maeda
,
Y.
, and
Hagiwara
,
Y.
, 2002, “
Turbulence Modification in a Homogeneous Turbulent Shear Flow Laden with Small Heavy Particles
,”
Int. J. Heat Fluid Flow
0142-727X,
23
, pp.
615
626
.
14.
Benson
,
M.
, 2003, “
The Effects of Wall Roughness on the Particle Velocity Field in a Fully-Developed Channel Flow
,” Engineer thesis, Stanford University, Stanford, California, 94305.
15.
Hussain
,
A.
, and
Reynolds
,
W.
, 1975, “
Measurements in a Fully Developed Turbulent Channel Flow
,”
Trans. ASME
0097-6822, Dec., pp.
558
580
.
16.
Varaskin
,
A.
,
Polezhaev
,
Y.
, and
Polyakov
,
A.
, 2000, “
Effect of Particle Concentration on Fluctuating Velocity of the Disperse Phase for Turbulent Pipe Flow
,”
Int. J. Heat Fluid Flow
0142-727X,
21
, pp.
562
567
.
17.
Li
,
Y.
, and
McLaughlin
,
J. B.
, 2001, “
Numerical Simulation of Particle-Laden Turbulent Channel Flow
,”
Phys. Fluids
1070-6631,
13
, pp.
2957
2967
.
18.
Boree
,
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.
0022-1120,
443
, pp.
129
165
.
19.
Sheen
,
H.
,
Chang
,
Y.
, and
Chiang
,
Y.
, 1993, “
Two-Dimensional Measurements of Flow Structure in a Two-Phase Vertical Pipe Flow
,”
Proc. Natl. Sci. Counc., Repub. China, Part A: Appl. Sci
0253-8415,
17
, pp.
200
213
.
20.
Bendat
,
J.
, and
Piersol
,
A.
, 2000,
Random Data Analysis and Measurement Procedures
,
Wiley Interscience
, New York.
21.
Coleman
,
H.
, and
Steele
,
W.
, 1989,
Experimentation and Uncertainty Analysis for Engineers
,
Wiley
, New York.
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