Mean radial and turbulent radial velocity profiles were measured in a circular jet at up to 40 jet diameters downstream of the jet exit using an LDA. The mean radial velocity in the ambient reservoir (the entrainment velocity) is found to be inversely proportional to the radial distance from the jet centerline. The coefficient of proportionality, c⁠, increases in the zone of flow establishment and reaches a constant after the transition zone. It is suggested that the traditional definition of entrainment velocity, which maintains direct proportionality to the local jet velocity by the entrainment coefficient, should be augmented by this inverse function.

Issue Section:
Technical Papers
Keywords:
turbulence, jets, stratified flow, velocity, laser Doppler anemometry
Topics:
Turbulence, Flow (Dynamics)
1.
Mih
,
W.
,
1989
, “
Equations for Axisymmetric and Two-Dimensional Turbulent Jets
,”
J. Hydraul. Eng.
,
115
(
12
), pp.
1715
–
1719
.
2.
Davies
,
P.
,
Fisher
,
M.
, and
Barratt
,
M.
,
1963
, “
The Characteristics of the Turbulence in the Mixing Region of a Round Jet
,”
J. Fluid Mech.
,
15
, pp.
337
–
367
.
3.
Wygnanski
,
I.
, and
Fiedler
,
H.
,
1969
, “
Some Measurements in the Self-Preserving Jet
,”
J. Fluid Mech.
,
38
, pp.
577
–
612
.
4.
Fukushima, C., Aanen, L., and Westerweel, K., 2000, “Investigation of the Mixing Process in an Axisymmetric Turbulent Jet Using PIV and LIF,” 10th Int. Symp. on Application of Laser Techniques to Fluid Mechanics, 19\0-13 July, Lisbon, Portugal.
5.
Kassab
,
S.
,
Bakry
,
A.
, and
Warda
,
H.
,
1996
, “
Laser Doppler Anemometry Measurements in an Axisymmetric Turbulent Jet
,”
Rev. Sci. Instrum.
,
67
(
5
), pp.
1842
–
1849
.
6.
Sami
,
S.
,
Carmody
,
T.
, and
Rouse
,
H.
,
1967
, “
Jet Diffusion in the Region of Flow Establishment
,”
J. Fluid Mech.
,
27
, pp.
231
–
252
.
7.
Kimura, M., Maeyama, M., Ono, K., and Saima, A., 1991. “Flow Structure in Near-Nozzle Region of Gas Jet,” Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Elsevier, New York.
8.
Liepmann
,
D.
, and
Gharib
,
M.
,
1992
, “
The Role of Streamwise Vorticity in the Near-Field Entrainment of Round Jets
,”
J. Fluid Mech.
,
245
, pp.
643
–
668
.
9.
List
,
E.
, and
Imberger
,
J.
,
1973
, “
Turbulent Entrainment in Buoyant Jets and Plumes
,”
J. Hydraul. Div., Am. Soc. Civ. Eng.
,
HY9
, pp.
1461
–
1474
.
10.
Morton
,
B. R.
,
Taylor
,
G. I.
, and
Turner
,
J. S.
,
1956
, “
Turbulent Gravitational Convection From Maintained and Instantaneous Sources
,”
Proc. R. Soc. London, Ser. A
,
A234
, pp.
1
–
23
.
11.
Turner
,
J.
,
1986
, “
Turbulent Entrainment: The Development of the Entrainment Assumption, and Its Application to Geophysical Flows
,”
J. Fluid Mech.
,
173
, pp.
431
–
471
.
12.
Capp, S., 1983, “Experimental Investigation of the Turbulent Axisymmetric Jet,” Ph.D. thesis, State University of New York at Buffalo, Buffalo, NY.
13.
Crow
,
S.
, and
Champagne
,
F.
,
1971
, “
Orderly Structure of Jet Turbulence
,”
J. Fluid Mech.
,
48
, pp.
547
–
596
.
14.
Fondse
,
H.
,
Leijdens
,
H.
, and
Ooms
,
G.
,
1983
, “
On the Influence of the Exit Conditions on the Entrainment Rate in the Development Region of a Free, Round, Turbulent Jet
,”
Appl. Sci. Res.
,
40
, pp.
355
–
375
.
15.
Hill
,
B.
,
1972
, “
Measurements of Local Entrainment Rate in the Initial Region of Axisymmetric Turbulent Air Jets
,”
J. Fluid Mech.
,
51
, pp.
773
–
779
.
16.
Hussain
,
A.
, and
Zaman
,
K.
,
1981
, “
The ‘Preferred Mode’ of the Axisymmetric Jet
,”
J. Fluid Mech.
,
110
, pp.
39
–
71
.
17.
Bayazitoglu
,
Y.
, and
Peterson
,
J.
,
1992
, “
Measurements of Velocity and Turbulence in Vertical Axisymmetric Isothermal and Buoyant Jets
,”
ASME J. Heat Transfer
,
114
, pp.
135
–
142
.
18.
Trabold
,
T.
,
Esen
,
E.
, and
Obot
,
N.
,
1987
, “
Entrainment by Turbulent Jets Issuing From Sharp-Edge Inlet Round Nozzles
,”
Trans. ASME
,
109
, pp.
248
–
254
.
19.
Ricou
,
F.
, and
Spalding
,
D.
,
1961
, “
Measurement of Entrainment by Axisymmetric Turbulent Jets
,”
J. Fluid Mech.
,
11
, pp.
21
–
32
.
20.
Hussein
,
H.
,
Capp
,
S.
, and
George
,
W.
,
1994
, “
Velocity Measurements in a High-Reynolds-Number, Momentum-Conserving, Axisymmetric, Turbulent Jet
,”
J. Fluid Mech.
,
258
, pp.
31
–
75
.
21.
ASME, 1998, “Test Uncertainty—Instruments and Apparatus—Supplement to ASME Performance Test Codes,” ASME, New York, PTC-19.1-1998.
22.
Coleman, H., and Steele, W., 1989, Experimentation and Uncertainty Analysis for Engineers, John Wiley and Sons, New York.
23.
Bruun, H., 1995, Hot-Wire Anemometry, Oxford University Press, New York.
24.
Buchave
,
P.
,
George
,
W. K.
, and
Lumley
,
J. L.
,
1979
, “
The Measurement of Turbulence With the Laser-Doppler Anemometer
,”
Annu. Rev. Fluid Mech.
,
11
, pp.
443
–
503
.
25.
George
,
W. K.
,
1988
, “
Quantitative Measurement With the Burst-Mode Laser-Doppler Anemometer
,”
Exp. Therm. Fluid Sci.
,
1
, pp.
29
–
40
.
26.
Rodko
,
A.
, and
Cataldo
,
J.
, 1999, “Interaction of Surface Waves and a Jet,” International Journal of Fluid Mechanics Research, 26, Nos. 5 and 6.
27.
Papanicolaou
,
P.
, and
List
,
E.
,
1988
, “
Investigations of Round Vertical Turbulent Buoyant Jets
,”
J. Fluid Mech.
,
195
, pp.
341
–
391
.
28.
Fisher, H., List, E., Koh, R., Imberger, J., and Brooks, N., 1979, Mixing in Inland and Coastal Waters, Academic Press, San Diego, CA.
29.
Boguslawski
,
L.
, and
Popiel
,
C.
,
1979
, “
Flow Structure of the Free Round Turbulent Jet in the Initial Region
,”
J. Fluid Mech.
,
90
, pp.
531
–
539
.
30.
Rodi, W., 1975, “A Review of Experimental Data of Uniform Density Free Turbulent Boundary Layers,” Studies in Convection, B. Launder ed., Academic Press, San Diego, CA.
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