An experimental investigation was carried out to study the turbulent flow behind passive grids in a subsonic wind tunnel. The enhanced level of turbulence was generated by five wicker metal grids with square meshes and different parameters (diameter of the grid rod d = 0.3 to 3 mm and the grid mesh size M = 1 to 30 mm). The velocity of the flow was measured by means of a one-dimensional hot-wire probe. For this purpose, skewness, kurtosis, and transverse variation of the velocity fluctuations were determined, obtaining knowledge of the degree of turbulence isotropy and homogeneity in the flow behind grids of variable geometry, for different incoming velocities U = 4, 6, 10, 15, 20 m/s. Approximately, the isotropic and homogeneous turbulence was obtained for x/M > 30. Next, several correlations for turbulence degeneration law were tested. Finally, as the main goal of the study, impact of turbulence intensity on bypass laminar–turbulent transition parameters (transition inception, shape parameter, and the length of the transition region) on a flat plate was investigated. Parameter ITum was created as an integral taken from the leading edge of the plate to the transition inception, divided by the distance from the leading edge to the transition inception, expressing in this way the averaged value of turbulence intensity.

References

References
1.
Morkovin
,
M. V.
,
1969
, “
On the Many Faces of Transition
,”
Viscous Drag Reduction
,
C. S.
Wells
, ed.,
Plenum
,
New York
, pp.
1
31
.
2.
Abu–Ghannam
,
B. J.
, and
Shaw
,
R.
,
1980
, “
Natural Transition of Boundary Layers–The Effects of Turbulence, Pressure Gradient, and Flow History
,”
J. Mech. Eng. Sci.
,
22
(
5
), pp.
213
228
.
3.
Mayle
,
R. E.
,
1991
, “
The Role of Laminar–Turbulent Transition in Gas Turbine Engines
,”
ASME J. Turbomach.
,
113
(
4
), pp.
509
537
.
4.
Hourmouziadis
,
J.
,
1989
,
Aerodynamics Design of Low Pressure Turbines
,
North Atlantic Treaty Organization Advisory Group for Aerospace Research and Development, Brussels
,
Belgium
.
5.
Valente
,
P. C.
, and
Vassilicos
,
J. C.
,
2011
, “
The Decay of Turbulence Generated by a Class of Multiscale Grids
,”
J. Fluid Mech.
,
687
, pp.
300
340
.
6.
Mydlarski
,
L.
, and
Warhaft
,
Z.
,
1996
, “
On the Onset of High-Reynolds-Number Grid-Generated Wind Tunnel Turbulence
,”
J. Fluid. Mech.
,
320
, pp.
331
368
.
7.
Gad-el-Hak
,
M.
, and
Corrsin
,
S.
,
1974
, “
Measurements of the Nearly Isotropic Turbulence Behind a Uniform Jet Grid
,”
J. Fluid Mech.
,
62
(
01
), pp.
115
143
.
8.
Hideharu
,
M.
,
1991
, “
Realization of a Large-Scale Turbulence Field in a Small Wind Tunnel
,”
Fluid Dyn. Res.
,
8
(
1–4
), pp.
53
64
.
9.
Mydlarski
,
L.
, and
Warhaft
,
Z.
,
1998
, “
Passive Scalar Statistics in High-Peclet-Number Grid Turbulence
,”
J. Fluid. Mech.
,
358
, pp.
135
175
.
10.
Birouk
,
M.
,
Sarh
,
B.
, and
Gokalp
,
I.
,
2003
, “
An Attempt to Realize Experimental Isotropic Turbulence at Low Reynolds Number
,”
Flow, Turbul. Combust.
,
70
(
1
), pp.
325
348
.
11.
Poorte
,
R. E. G.
, and
Biesheuvel
,
A.
,
2001
, “
Experiments on the Motion of Gas Bubbles in Turbulence Generated by an Active Grid
,”
J. Fluid Mech.
,
461
, pp.
127
154
.
12.
Kang
,
H. S.
,
Chester
,
S.
, and
Meneveau
,
C.
,
2003
, “
Decaying Turbulence in an Active-Grid-Generated Flow and Comparisons With Large-Eddy Simulation
,”
J. Fluid Mech.
,
480
, pp.
129
160
.
13.
Obligado
,
M.
,
Cartellier
,
A.
,
Mininni
,
P.
,
Teitelabaum
,
T.
, and
Bourgoin
,
M.
,
2014
, “
Preferential Concentration of Heavy Particles in Turbulence
,”
J. Turbul.
,
15
(
5
), pp.
293
310
.
14.
Johnson
,
M. W.
, and
Pinarbasi
,
A.
,
2014
, “
The Effect of Pressure Gradient on Boundary Layer Receptivity
,”
Flow, Turbul. Combust.
,
93
(
1
), pp.
1
24
.
15.
Kurian
,
T.
, and
Fransson
,
J. H. M.
,
2009
, “
Grid-Generated Turbulence Revisited
,”
Fluid Dyn. Res.
,
41
(
2
), p.
021403
.
16.
Dryden
,
H. L.
,
Schubauer
,
G. B.
,
Mock
,
W. C.
, Jr.
, and
Skramstad
,
H. K.
,
1937
, “
Measurements of Intensity and Scale of Wind Tunnel Turbulence and Their Relation to the Critical Reynolds Number of Spheres
,” National Aeronautics and Space Administration, Washington, DC, Technical
Report No. NACA-TR-581
.
17.
Hinze
,
J. O.
,
1953
,
Turbulence
,
2nd ed.
,
McGraw-Hill
,
New York
.
18.
Batchelor
,
G. K.
,
1953
,
The Theory of Homogeneous Turbulence
,
Cambridge University Press
,
Cambridge, UK
.
19.
Mohamed
,
M. S.
, and
LaRue
,
J. C.
,
1990
, “
The Decay Power Law in Grid-Generated Turbulence
,”
J. Fluid Mech.
,
219
, pp.
195
214
.
20.
Ting
,
D. S. K.
,
2013
,
Some Basics of Engineering Flow Turbulence
,
revised ed.
,
Naomi Ting's Book
,
Windsor, ON, Canada
.
21.
Jimenez
,
J.
,
1998
, “
Turbulent Velocity Fluctuations Need to be Gaussian
,”
J. Fluid Mech.
,
376
, pp.
139
147
.
22.
Tresso
,
R.
, and
Munoz
,
D. R.
,
2000
, “
Homogeneous, Isotropic Flow in Grid Generated Turbulence
,”
ASME J. Fluids Eng.
,
122
(
1
), pp.
51
56
.
23.
Fouladi
,
F.
,
Henshaw
,
P.
, and
Ting
,
D. S. K.
,
2015
, “
Turbulent Flow Over a Flat Plate Downstream of a Finite Height Perforated Plate
,”
ASME J. Fluids Eng.
,
137
(
2
), p.
021203
.
24.
Roach
,
P. E.
,
1986
, “
The Generation of Nearly Isotropic Turbulence by Means of Grids
,”
J. Heat Fluid Flow
,
8
(
2
), pp.
82
92
.
25.
Baines
,
W. D.
, and
Peterson
,
E. G.
,
1951
, “
An Investigation of Flow Through Screens
,”
ASME J. Fluids Eng.
,
73
, pp.
467
480
.
26.
Mikhailova
,
N. P.
,
Repik
,
E. U.
, and
Sosedko
,
Y. P.
,
2005
, “
Reynolds Number Effect on the Grid Turbulence Degeneration Law
,”
Fluid Dyn.
,
40
(
5
), pp.
714
725
.
27.
Comte–Bellot
,
G.
, and
Corrsin
,
S.
,
1966
, “
The Use of a Contraction to Improve the Isotropy of Grid-Generated Turbulence
,”
J. Fluid. Mech.
,
25
(
04
), pp.
657
682
.
28.
Batchelor
,
G. K.
, and
Townsend
,
A. A.
,
1948
, “
Decay of Isotropic Turbulence in the Initial Period
,”
Proc. R. Soc. A
,
193
(
1035
), pp.
539
558
.
29.
Krogstad
,
P. A.
, and
Davidson
,
P. A.
,
2010
, “
Is Grid Turbulence Saffman Turbulence?
,”
J. Fluid Mech.
,
642
, pp.
373
394
.
30.
George
,
W. K.
,
1988
, “
The Decay of Homogeneous Turbulence
,”
Transport Phenomena in Turbulent Flows
,
M.
Hirata
, and
N.
Kasagi
, eds.,
Routledge
,
New York
.
31.
Lavoie
,
P.
,
Djenidi
,
L.
, and
Antonia
,
R. A.
,
2007
, “
Effects of Initial Conditions in Decaying Turbulence Generated by Passive Grids
,”
J. Fluid Mech.
,
585
, pp.
395
420
.
32.
Warhaft
,
Z.
, and
Lumley
,
J. L.
,
1978
, “
The Decay of Temperature Fluctuations and Heat Flux in Grid Generated Turbulence
,”
Lecture Notes in Physics
,
Springer–Verlag
,
Berlin
, pp.
113
123
.
33.
Torrano
,
I.
,
Tutar
,
M.
,
Martinez–Agirre
,
M.
,
Rouquier
,
A.
,
Mordant
,
N.
, and
Bourgoin
,
M.
,
2015
, “
Comparison of Experimental and RANS-Based Numerical Studies of the Decay of Grid-Generated Turbulence
,”
ASME J. Fluids Eng.
,
137
(
6
), p.
061203
.
34.
Dhawan
,
S.
, and
Narasimha
,
R.
,
1958
, “
Some Properties of Boundary Layer Flow During the Transition From Laminar to Turbulent Motion
,”
J. Fluid Mech.
,
3
(
4
), pp.
418
436
.
35.
Blasius
,
P. R. H.
,
1913
, “
Das Aehnlichkeitsgesetz bei Reibungsvorgangen in Flüssigkeiten
,”
Forschungsheft
,
131
, pp.
1
41
.
36.
Townsend
,
A. A.
,
1948
, “
Local Isotropy in the Turbulent Wake of a Cylinder
,”
Aust. J. Sci. Res. A: Phys. Sci.
,
1
, pp.
161
174
.
37.
Emmons
,
H. W.
,
1951
, “
The Laminar-Turbulent Transition in a Boundary Layer—Part I
,”
J. Aeronaut. Sci.
,
18
(
7
), pp.
490
498
.
38.
Wiercinski
,
Z.
,
1997
, “
The Stochastic Theory of the Natural Laminar-Turbulent Transition in the Boundary Layer
,”
Transactions of the Institute of Fluid-Flow Machinery
,
102
, pp.
89
110
.
39.
Lipson
,
C.
, and
Sheth
,
N. J.
,
1973
,
Statistical Design and Analysis of Engineering Experiments
,
McGraw-Hill
,
New York
.
40.
Wadsworth
,
H. M.
,
1989
,
Handbook of Statistical Methods for Engineers and Scientists
,
McGraw-Hill
,
New York
.
41.
Wiercinski
,
Z.
,
1995
, “
The Measurements of the Intermittency Factor in the Region of Laminar-Turbulent Transition in the Boundary Layer Over a Flat Plate
,” Report of the Institute of Fluid-Flow Machinery, Polish Academy of Science, Gdansk, Poland, Report No. 363/95 (in Polish).
42.
Keller
,
F. J.
, and
Wang
,
T.
,
1993
, “
Effects of Criterion Functions on Intermittency in Heated Transitional Boundary Layers With and Without Streamwise Acceleration
,”
ASME
Paper No. 93-GT-067.
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