Research Journal of Recent Sciences ________________________________________________ ISSN 2277 - 2502
Vol. 1(ISC-2011), 304-309 (2012)
Res.J.Recent.Sci.

Thermal and Hydrodynamic Analysis of the Impingement
Cooling inside a Backward Facing Step Flow
Khudheyer S. Mushatet
College of Engineering, Thiqar University, Nassiriya, IRAQ

Available online at: www.isca.in
(Received 16th September 2011, revised 11th January 2012, accepted 25th January 2012)

Abstract
The heat transfer and fluid flow of multiple confined impinging jets impinge normally to the backward facing step cross flow has
been numerically investigated. Different sizes of impinging jets were tested while the channel contraction ratio(SR) was ranged
from 0.25 to 0.5. The continuity, Navier-Stockes and energy equations were solved numerically. The discretized form of these
equations was obtained by using finite volume method with staggered grid technique. A Fortran built home computer code
depending on SIMPLE algorithm was developed to obtain the numerical results. The standard k-ε model is used to treat the
effect of turbulence while the wall functions laws were used to treat the regions near the solid walls. The aim of this study is to
show how multiple confined impinging jets can be a controlling factor to enhance the rate of heat transfer form the hot surface
of the channel backward facing step flow. The conducted results show that the heat transfer is enhanced significantly when
using multiple impinging jets. The highest heat transfer was found closer to the region of the facing step. Also the results show
that the rate of heat transfer is increased as the jets sizes increase.
Keywords : Impingement cooling, duct flow, backward facing step.

References
1. Nobuhide Kasagi Akio Matsunaga, Three- Dimensional
particle – Tracking – Velocimeter velocimetry
measurement of Turbulennce Statistics and Energy
Budget in a backward-Facing Step Flow, Int. J. Heat
and Fluid Flow, 16, 477-485 (1995)
2. Lio T., Hwang J., Developing Heat Transfer and
Friction in a Ribbed Rectangular Duct with Flow
Separation at Inlet, ASME. J. Heat Transfer, 114, 546-
573 (1992)
3. Lio T.M., Hwang G.G. and Chen S.H., Simulation and
Measurements of Enhanced Turbulent Heat Transfer in
Channels With Periodic Ribs on One Principal Wall,
International Journal of Heat Mass Transfer, 36, 507-
507 (1993)
4. Rau G., Cakan M., Moeller D. and Arts T., The Effect
of Periodic Ribs on The Local Aerodynamics and Heat
Transfer Performance of A Straight Cooling Channel,
ASME Journal of Turbomachinery, 120, 368-375
(1988)
5. Han J.C, Heat Transfer and Friction Characteristics in
Rectangular Channels With Rib Turbulators, ASME
Journal of Heat Transfer, 110, 91-98 (1988)
6. Abe K. and Kondoh T., A new Turbulent Model for
Predicting Fluid Flow and Heat transfer in Separating
and Reattacing flows, 37, 139-151 (1994)
7. Srba Jovice and David M. Driver, Backward Facing
Step Measurements at Low Reynolds Number,
Reh=500, NASA, California 94035-1000 (1994).
8. Ichimiya K. and Hosaka N., Experimental Study of
Heat Transfer Characteristics Due To Confined
Impinging Two Dimensional Jet Exp. Thermal and
Fluid Science, 5, 803-807 (1992)
9. Zhang H.Q., Chan C.K. and Lau K.S, Numerical
Solution of Sudden Expansion Particle-Laden Flows
Using an Improved Stochastic Flow Model, Numerical
Heat Transfer, Part A, 4089-102 ( 2001)
10. Wang B., Zhang H.Q. and Wang X.L., Large Eddy
Simulation of Particle Response to Turbulence along its
Trajectory in a Back Word-Facing Step Turbulent
Flow, Int. J. Heat Mass Transfer, 49, 415-420 (2006)
11. Thangam S. and Knight D., Effect of Step Height on
The Separated Flow Past a Backward Facing Step,
Phys. Fluids, 3, 604-606 (1989)
12. Nie J.H. and Armaly B.F., Three Dimensional
Convective Flow Adjacent to a Backward Facing Stepeffects
of Step Height, Int. J. Heat Mass Transfer, 45,
2431-2438 (2002)
13. Rhee G.H. and Sung H.G., Enhancement of Heat
Transfer in Turbulent Separated and Re-Attachment
Flow by Local Forcing, Numerical Heat Transfer, Part
A, l37, 733-735 (2000)
14. Jones W.P. and Lunder B.E., The Prediction of
Laminarization with a Two Equation Model of
Turbulence, J. Heat Mass transfer (1972)
15. Versteege H.K. and Malalasekera W., An Introduction
of Computational Fluid Dynamics, Hemisophere
Publishing Corporation, United State of America (1995)