Gas jet flows expanding into a space containing the same medium but at a significant temperature difference are of concern in many fields of engineering. One such example is the expansion of supersonic oxygen jets in the basic oxygen furnace (BOF) steelmaking process. While studying the characteristics of such gas jets, an interesting invariance of the local Mach number with the change in the surrounding temperature was found. The velocity and temperature of the jet at any given location increased with the increasing ambient temperature. However, the local Mach number remained the same for all ambient temperatures. This interesting result was further studied since there is no mention of it in any published literature. The reasons for these characteristics of the jet are analyzed in this paper. It is stressed that this finding is of practical importance and can be used in experimental studies of submerged gas jets expanding into environments with different ambient temperatures.

Issue Section:
Forced Convection
Keywords:
jets, Mach number, supersonic flow
Topics:
Jets, Mach number, Temperature
1.
Bickley
,
W.
, 1937, “
The Plane Jet
,”
Phil. Mag.
,
23
, pp.
727
–
731
.
Crossref
Search ADS
 
2.
Schlichting
,
H.
, 1933, “
Laminare Strahlenausbreitung
,”
Z. Angew. Math. Mech.
0044-2267,
13
, pp.
260
–
263
.
Crossref
Search ADS
 
3.
Squire
,
H. B.
, 1951, “
The Round Laminar Jet
,”
Q. J. Mech. Appl. Math.
0033-5614,
4
, pp.
321
–
329
.
Crossref
Search ADS
 
4.
Squire
,
H. B.
, 1955, “
Radial Jets
,”
Fifty Years of Boundary Layer Research
,
W.
Tollmien
 and
H.
Görtler
, eds.,
Vieweg
,
Braunschweig, Germany
, pp.
47
–
54
.
5.
Krzywoblocki
,
M. Z.
, 1949, “
On Steady, Laminar Round Jets in Compressible Viscous Gases for Behind the Mouth
,”
Oesterr. Ing.-Arch.
0369-7819,
3
, pp.
373
–
383
.
6.
Pack
,
D. C.
, 1954, “
Laminar Flow in an Axially Symmetrical Jet of Compressible Fluid Far From the Orifice
,”
Proc. Cambridge Philos. Soc.
0068-6735,
50
, pp.
98
–
104
.
Crossref
Search ADS
 
7.
Goertler
,
H.
, 1954, “
Decay of Swirl in an Axially Symmetrical Jet Far From the Orifice
,”
Rev. Mat. Hisp.-Am.
0373-0999,
14
, pp.
143
–
178
.
8.
Howarth
,
L.
, 1938, “
Concerning the Velocity and Temperature Distributions in Plane and Axially Symmetrical Jets
,”
Proc. Cambridge Philos. Soc.
0068-6735,
34
, pp.
185
–
203
.
Crossref
Search ADS
 
9.
Durst
,
F.
, 2006,
Theorie and Praxis der Stroemungsmechanik – eine Einfuehrung
,
Springer-Verlag
,
Berlin
.
10.
Schlichting
,
H.
, 1979,
Boundary Layer Theory
,
McGraw-Hill
,
New York
.
11.
Abramovich
,
G. N.
, 1963,
The Theory of Turbulent Jets
,
Massachusetts Institute of Technology
,
Cambridge, MA
.
12.
Pai
,
S. L.
, 1954,
Fluid Dynamics of Jets
,
Van Nostrand
,
New York
.
13.
Prandtl
,
L.
, 1935, “
The Mechanics of Viscous Fluids
,”
Aerodynamic Theory
, Vol.
1
W. F.
Durand
, ed., pp.
16
–
208
.
14.
Görtler
,
H.
, 1942, “
Berechnung von Aufgaben der freien Turbulenze auf Grund eines neuen Naherungsansatzes
,”
Z. Angew. Math. Mech.
0044-2267,
22
, pp.
244
–
254
.
Crossref
Search ADS
 
15.
Hinze
,
J. O.
, and
van der H Zijnon
,
B. G.
, 1948, “
Transfer of Heat and Matter in the Turbulent Mixing Zone of an Axially Symmetric Jet
,”
Proceedings of the 7th International Congress for Applied Mechanics
, Vol.
2
, pp.
286
–
299
.
16.
Reichardt
,
H.
, 1941, “
Ueber eine neue Theorie der freien Turbulenz
,”
Z. Angew. Math. Mech.
0044-2267,
21
, pp.
257
–
264
.
Crossref
Search ADS
 
17.
Bejan
,
A.
, 1995,
Convection Heat Transfer
, 2nd ed.,
Wiley
,
New York
, Chap. 8.
Copyright © 2010
 by American Society of Mechanical Engineers
You do not currently have access to this content.