The evolution of the streamwise momentum flux for two turbulent, plane, parallel jets discharging through slots in a direction normal to a wall was studied both numerically and experimentally. The numerical results, obtained by solving the Reynolds-averaged Navier-Stokes equations employing a standard $k−ε$ turbulence model, predicted to within experimental error measured integrals of the momentum flux downstream of the merge point for jet spacing $S/d=5.$ Integration of the streamwise component of the Reynolds-averaged Navier-Stokes equations over a control volume results in an integral constant that was evaluated numerically for jet spacings $S/d=3,$ 5, 7, 9, and 11, and for different levels of turbulence kinetic energy and dissipation rate at the jet inlet boundaries. Results revealed that the integral constant is decreased as the jet spacing increases, and is also decreased as jet entrainment rates are increased due to higher levels of inlet turbulence kinetic energy, or alternatively, decreased levels of dissipation rate. Streamwise distance to the merge point was also found to decrease for increased levels of turbulence kinetic energy or decreased levels of dissipation rate at the jet inlet.

1.
Thomas
,
F. O.
,
1991
, “
Structure of Mixing Layers and Jets
,”
Appl. Mech. Rev.
,
44
, pp.
119
153
.
2.
Everitt
,
K. W.
, and
Robins
,
A. G.
,
1978
, “
The Development and Structure of Turbulent Plane Jets
,”
J. Fluid Mech.
,
88
, pp.
563
568
.
3.
Gutmark
,
E.
, and
Wygnanski
,
I.
,
1976
, “
The Planar Turbulent Jet
,”
J. Fluid Mech.
,
73
, pp.
465
495
.
4.
ASHRAE Handbook of Fundamentals, 1997, Ch. 15, p. 10, American Society of Heating, Refrigerating and Air Conditioning Engineers, Atlanta, GA.
5.
Tanaka
,
E.
,
1970
, “
The Interference of Two-Dimensional Parallel Jets (1st Report, Experiments on Dual Jet)
,”
Bull. JSME
,
13
(
56
), pp.
272
280
.
6.
Tanaka
,
E.
,
1974
, “
The Interference of Two-Dimensional Parallel Jets (2nd Report, Experiments on the Combined Flow of Dual Jet)
,”
Bull. JSME
,
17
(
109
), pp.
920
927
.
7.
Elbanna
,
H.
,
Gahin
,
S.
, and
Rashed
,
M. I. I.
,
1983
, “
Investigation of Two Plane Parallel Jets
,”
AIAA J.
,
21
, pp.
986
990
.
8.
Lin
,
Y. F.
, and
Sheu
,
M. J.
,
1990
, “
Investigation of Two Plane Parallel Unventilated Jets
,”
Exp. Fluids
,
10
, pp.
17
22
.
9.
Lin
,
Y. F.
, and
Sheu
,
M. J.
,
1991
, “
Interaction of Parallel Turbulent Plane Jets
,”
AIAA J.
,
29
, pp.
1372
1373
.
10.
Nasr
,
A.
, and
Lai
,
J. C. S.
, “
Comparison of Flow Characteristics in the Near Field of Two Parallel Plane Jets and an Offset Plane Jet
,”
Phys. Fluids
,
9
, pp.
2919
2931
.
11.
Nasr
,
A.
, and
Lai
,
J. C. S.
, “
Effects of Nozzle Spacing on the Development of Two Parallel Plane Jets
,”
International Journal of Transport Phenomena
,
2
, pp.
43
56
.
12.
Anderson
,
E. A.
, and
Spall
,
R. E.
,
2001
, “
Experimental and Numerical Investigation of Two-Dimensional Parallel Jets
,”
J. Fluids Eng.
,
123
, pp.
401
406
.
13.
Spall
,
R. E.
,
2002
, “
A Numerical Study of Buoyant, Plane Parallel Jets
,”
J. Heat Transfer
,
124
, pp.
1210
1213
.
14.
Anderson
,
E. A.
,
Snyder
,
D. O.
, and
Christensen
,
J.
,
2003
, “
Periodic Flow Between Low Aspect Ratio Parallel Jets
,”
J. Fluids Eng.
,
125
, pp.
389
392
.
15.
Yang, H. Q., and Przekwas, A. J., “Pressure-based High-Order TVD Methodology for Dynamic Stall Simulation,” AIAA-93-0680.
16.
Mathieu, J., and Scott, J., 2000, An Introduction to Turbulent Flow, Cambridge University Press, pp. 164–168.
17.
Nasr
,
A.
, and
Lai
,
J. C. S.
, “
Two Parallel Plane Jets: Mean Flow and Effects of Excitation
,”
Exp. Fluids
,
22
, pp.
251
260
.
18.
Taylor, J. R., 1997, An Introduction to Error Analysis, 2nd edition, University Science Books.