A computational study is presented of the heat transfer performance of a micro-scale, axisymmetric, confined jet impinging on a flat surface with an embedded uniform heat flux disk. The jet flow occurs at large, subsonic Mach numbers (0.2 to 0.8) and low Reynolds numbers (419 to 1782) at two impingement distances. The flow is characterized by a Knudsen number of 0.01, based on the viscous boundary layer thickness, which is large enough to warrant consideration of slip-flow boundary conditions along the impingement surface. The effects of Mach number, compressibility, and slip-flow on heat transfer are presented. The local Nusselt number distributions are shown along with the velocity, pressure, density and temperature fields near the impingement surface. Results show that the wall temperature decreases with increasing Mach number, M, exhibiting a minimum local value at r/R=1.6 for the highest M. The slip velocity also increases with M, showing peak values near r/R=1.4 for all M. The resulting Nusselt number increases with increasing M, and local maxima are observed near r/R=1.20, rather than at the centerline. In general, compressibility improves heat transfer due to increased fluid density near the impinging surface. The inclusion of slip-velocity and the accompanying wall temperature jump increases the predicted rate of heat transfer by as much as 8–10% for M between 0.4 and 0.8.

1.
Campbell Jr., J. S., Black, W. Z., Glezer, A., and Hartley, J. G., 1998, “Thermal Management of a Laptop Computer With Synthetic Air Microjets,” Proceedings of the 1998 6th Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems, IEEE, pp. 43–50.
2.
Allan
,
R.
, 1999, “MEMS Micro Heat Exchanger Employ Impinging Jets to Boost Cooling Efficiency,” Electronic Design, 47(7), pp. 29–30.
3.
Martin, H., 1977, “Heat and Mass Transfer between Impinging Gas Jets and Solid Surfaces,” Advances in Heat Transfer, J. P. Hartnett and T. F. Irvine, Jr., eds., 13, Academic Press, New York.
4.
Hrycak
,
P.
,
1983
, “
Heat Transfer from Round Impinging Jets to a Flat Plate
,”
Int. J. Heat Mass Transf.
,
26
(
12
), pp.
1857
1865
.
5.
Lytle
,
D.
, and
Webb
,
B. W.
,
1994
, “
Air Jet Impingement Heat Transfer at Low Nozzle-Plate Spacings
,”
Int. J. Heat Mass Transf.
,
37
(
12
), pp.
1687
1697
.
6.
Arjocu
,
S. C.
, and
Liburdy
,
J. A.
,
2000
, “
Identification of Dominant Heat Transfer Modes Associated with the Impingement of an Elliptic Jet Array
,”
ASME J. Heat Transfer
,
122
, pp.
240
247
.
7.
Failla
,
G.
,
Bishop
,
E.
, and
Liburdy
,
J. A.
, 2000, “Enhanced Jet Impingement Heat Transfer with Crossflow at Low Reynolds Numbers,” Journal of Electronics Manufacturing, 9(2), pp. 167–178.
8.
Huber
,
A. M.
, and
Viskanta
,
R.
,
1994
, “
Effect of Jet-Jet Spacing on Convective Heat Transfer to Confined, Impinging Arrays of Axisymmetric Jets
,”
Int. J. Heat Mass Transf.
,
37
(
18
), pp.
2859
2869
.
9.
Chatterjee
,
A.
, and
Deviprasath
,
L. J.
,
2001
, “
Heat Transfer in Confined Laminar Axisymmetric Impinging Jets at Small Nozzle-Plate Distances: The Role of Upstream Vorticity Diffusion
,”
Numer. Heat Transfer, Part A
,
39
, pp.
777
800
.
10.
Scholtz
,
M. T.
, and
Trass
,
O.
,
1970
, “
Mass Transfer in a Nonuniform Impinging Jet: Part II. Boundary Layer Flow-Mass Transfer
,”
AIChE J.
,
16
, pp.
90
96
.
11.
Colucci
,
D. W.
, and
Viskanta
,
R.
,
1996
, “
Effect of Nozzle Geometry on Local Convective Heat Transfer
,”
ASME J. Heat Transfer
,
13
, pp.
71
80
.
12.
Beskok
,
A.
, and
Karniadakis
,
G. E.
,
1994
, “
Simulation of Heat and Momentum Transfer in Complex Microgeometries
,”
J. Thermophys. Heat Transfer
,
8
(
4
), pp.
647
655
.
13.
Schaaf, S. A., and Chambre, P. L., 1961, Flow of Rarefied Gases, Princeton University Press, Princeton, NJ.
14.
Polat
,
S.
,
Huang
,
B.
,
Mujumdar
,
A. S.
, and
Douglas
,
W. J. M.
,
1989
, “
Numerical Flow and Heat Transfer Under Impinging Jets: A Review
,”
Annu. Rev. Numer. Fluid Mech. Heat Transfer
,
2
, pp.
157
197
.
15.
Kennard, E. H., 1938, Kinetic Theory of Gases, McGraw-Hill Book Co. New York.
16.
Karniadakis, G. E., and Beskok, A., 2001, Microflows Fundamentals and Simulation, Springer-Verlag, New York.
17.
Pelfrey
,
J. R. R.
, and
Liburdy
,
J. A.
,
1986
, “
Mean Flow Characteristics of a Turbulent Offset Set
,”
J. Fluids Eng.
,
108
, pp.
82
88
.
18.
Morris
,
G. K.
,
Garimella
,
S. V.
, and
Amano
,
R. S.
,
1996
, “
Prediction of Jet Impingement Heat Transfer Using a Hybrid Wall Treatment With Different Turbulent Prandtl Number Functions
,”
ASME J. Heat Transfer
,
118
, pp.
562
569
.
You do not currently have access to this content.