An experimental investigation of a nonreacting multiple jet mixing with a confined crossflow has been conducted. Flow and geometric conditions were varied in order to examine favorable parameters for mixing. The requirement for a rapid and intense mixing process originates from combustion applications, especially the RQL-combustion concept. Thus, the jets were perpendicularly injected out of one opposed row of circular orifices into a heated crossflow in a rectangular duct. Spacing and hole size were varied within the ranges referring to combustor applications. The results presented are restricted to an in-line orientation of opposed jet axis. Temperature distribution, mixing rate, and standard deviation were determined at discrete downstream locations. Best, i.e., uniform mixing can be observed strongly depending on momentum flux ratio. For all geometries investigated, an optimum momentum flux ratio yields to a homogeneous temperature distribution in the flow field downstream of the injection plane. Overly high ratios deteriorate the mixing process due to the mutual impact of the opposed entraining jets along with a thermal stratification of the flowfield. Correlations are introduced describing the dependency of optimum momentum flux ratio on mixing hole geometry. They allow the optimization of jet-in-crossflow mixing processes in respect to uniform mixing.

1.
Doerr, Th., and Hennecke, D. K., 1993, “The Mixing Process in the Quenching Zone of the Rich-Lean-Combustion Concept,” Proc. 81st Symposium on “Fuels and Combustion Technology for Advanced Aircraft Engines,” AGARD-PEP Fiuggi.
2.
Doerr, Th., 1995, “Ein Beitrag zur Reduzierung des Stickoxydausstoßes von Gasturbinenbrennkammern—Die Optimierung des Mischungsprozesses der Fett-Mager-Stufenverbrennung,” Ph.D. Thesis, Darmstadt, Germany.
3.
Holdeman
J. D.
, and
Walker
R. E.
,
1977
, “
Mixing of a Row of Jets With a Confined Crossflow
,”
AIAA Journal
, Vol.
15
, No.
2
, pp.
243
249
.
4.
Holdeman
J. D.
,
Srinivasan
R.
,
Coleman
E. B.
,
Meyers
G. D.
, and
White
C. D.
,
1987
, “
Effects of Multiple Rows and Noncircular Orifices on Dilution Jet Mixing
,”
AIAA Journal of Propulsion and Power
, Vol.
3
, No.
3
, pp.
219
226
.
5.
Holdeman
J. D.
,
1990
, “
Mixing of Multiple Jets With a Confined Subsonic Crossflow
,”
Prog. Energy Combustion Science
, Vol.
19
, pp.
31
70
.
6.
Kamotani, Y., and Greber, I., 1974, “Experiments on Confined Turbulent Jets in Crossflow,” NASA CR-2392.
7.
Liscinsky, D. S., True, B., Vranos, A., and Holdeman, J. D., 1992, “Experimental Study of Cross-Stream Mixing in a Rectangular Duct,” Paper No. AIAA-92-3090.
8.
Liscinsky, D. S., True, B., and Holdeman, J. D., 1993, “Experimental Investigation of Cross Flow Jet Mixing in a Rectangular Duct,” Paper No. AIAA-93-3037.
9.
Liscinsky, D. S., True, B., and Holdeman, J. D., 1994, “Mixing Characteristics of Directly Opposed Rows of Jets Injected Normal to a Crossflow in a Rectangular Duct,” Paper No. AIAA-94-0217.
10.
Simon
B.
,
1990
, “
Entwicklung neuer Brennkammerkonzepte fu¨r schadstoffarme Flugzeugantriebe
,”
MTU Focus
, Vol.
2
, pp.
10
17
.
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