This study examines a horizontal wall jet impinging onto a forward facing vertical step in a cross-flow. Planar laser induced fluorescence (PLIF) experiments in a 68×40mm2 water channel indicate how the wall-jet flow after impinging onto the step becomes a vertical jet with an elliptical cross section. This study proposes predictive empirical correlations for the aspect ratio and perimeter of the jet’s elliptical cross section based on the step geometry and the inlet flow conditions. A numerical model is also presented, which was produced from a commercial Reynolds averaged Navier–Stokes computational fluid dynamics (CFD) code with the k-ϵ closure model. The experimental results were well represented by correlations for the perimeter P and aspect ratio S using the parameters H (the step height), L (the distance from the jet represented as a point source to the step), and R (the velocity ratio). The CFD simulation was able to predict the trends in the perimeter (under different conditions), aspect ratio, and the shape of the concentration profile, but overpredicted the jet’s perimeter by approximately 50%. The results of these tests are required as input parameters when modeling jet trajectories.

1.
Wilson
,
D. J.
, 1979, “
The Release and Dispersion of Gas From Pipeline Ruptures
,” Alberta Environment, Contract No. 790686.
2.
Walker
,
D. A.
, 1987, “
A Fluorescence Technique for Measurement of Concentration in Mixing Liquids
,”
J. Phys. E
0022-3735,
20
, pp.
217
224
.
3.
Cusworth
,
R. A.
, and
Sislian
,
J. P.
, 1987, “
Computation of Turbulent Free Isothermal Swirling Jets
,” University of Toronto Institute for Aerospace Studies, Technical Report No. 315.
4.
Behnia
,
M.
,
Parneix
,
S.
, and
Durbin
,
P. A.
, 1998, “
Prediction of Heat Transfer in an Axisymmetric Turbulent Jet Impinging on a Flat Plate
,”
Int. J. Heat Mass Transfer
0017-9310,
41
(
12
), pp.
1845
1855
.
5.
Hilderman
,
T. L.
, and
Wilson
,
D. J.
, 2007, “
Predicting Plume Meandering and Averaging Time Effects on Mean and Fluctuating Concentrations in Atmospheric Dispersion Simulated in a Water Channel
,”
Boundary-Layer Meteorol.
0006-8314,
122
, pp.
535
575
.
6.
Shahzad
,
K.
,
Fleck
,
B. A.
, and
Wilson
,
D. J.
, 2007, “
Small Scale Modeling of Vertical Surface Jets in Cross-Flow: Reynolds Number and Downwash Effects
,”
ASME J. Fluids Eng.
0098-2202,
129
, pp.
311
318
.
7.
Johnston
,
C. R.
, and
Wilson
,
D. J.
, 1997, “
A Vortex Pair Model for Plume Downwash Into Stack Wakes
,”
Atmos. Environ.
1352-2310,
31
(
1
), pp.
13
20
.
8.
Powell
,
I.
, 1987, “
Design of a Laser Beam Line Expander
,”
Appl. Opt.
0003-6935,
26
(
17
), pp.
3705
3709
.
9.
Torres
,
L. A.
, 2008, “
Turbulent Round Jet in a Counter Flow: Effects of Small Inlet Yaw Angle
,” MS thesis, University of Alberta, Edmonton, Alberta, Canada.
10.
Launder
,
B. E.
, and
Spalding
,
D. B.
, 1974, “
Numerical Computation of Turbulent Flows
,”
Comput. Methods Appl. Mech. Eng.
0045-7825,
3
, pp.
269
289
.
11.
Grotjans
,
H.
, and
Menter
,
F.
, 1998, “
Wall Functions for General Application CFD Codes
,”
Proceedings of the Fourth European Computational Fluid Dynamics Conference
,
Wiley
,
New York
, Vol.
1
, pp.
1112
1117
.
12.
Pope
,
S. B.
, 2000,
Turbulent Flows
,
Cambridge University Press
,
New York
.
13.
Roache
,
P. J.
, 1997, “
Quantification of Uncertainty in Computational Fluid Dynamics
,”
Annu. Rev. Fluid Mech.
0066-4189,
29
, pp.
123
160
.
14.
de Vahl Davis
,
G.
, 1983, “
Natural Convection of Air in a Square Cavity: A Bench Mark Numerical Solution
,”
Int. J. Numer. Methods Fluids
0271-2091,
3
, pp.
249
264
.
15.
Fletcher
,
C. A. J.
, 1991,
Computational Techniques for Fluid Dynamics
,
2nd ed.
,
Springer-Verlag
,
Berlin
, Vol.
1
.
16.
Andreasson
,
P.
, and
Svensson
,
U.
, 1992, “
A Note on a Generalized Eddy-Viscosity Hypothesis
,”
ASME J. Fluids Eng.
0098-2202,
114
, pp.
463
466
.
17.
Hanjalić
,
K.
, 1994, “
Advanced Turbulence Closure Models: A View of Current Status and Future Prospects
,”
Int. J. Heat Fluid Flow
0142-727X,
15
(
3
), pp.
178
203
.
You do not currently have access to this content.