Spray cooling of a hot surface was investigated to ascertain the effect of nozzle-to-surface distance on critical heat flux (CHF). Full cone sprays of Fluorinert FC-72 and FC-87 were used to cool a 12.7 × 12.7 mm2 surface. A theoretical model was constructed that accurately predicts the spray’s volumetric flux (liquid volume per unit area per unit time) distribution across the heater surface. Several experimental spray sampling techniques were devised to validate this model. The impact of volumetric flux distribution on CHF was investigated experimentally. By measuring CHF for the same nozzle flow rate at different nozzle-to-surface distances, it was determined CHF can be maximized when the spray is configured such that the spray impact area just inscribes the square surface of the heater. Using this optimum configuration, CHF data were measured over broad ranges of flow rate and subcooling, resulting in a new correlation for spray cooling of small surfaces.

Issue Section:
Boiling and Condensation
Keywords:
Boiling, Electronic Equipment, Sprays/Droplets
Topics:
Cooling, Critical heat flux, Sprays
1.
Bolle, L., and Moureau, J. C., 1976, “Spray Cooling of Hot Surfaces: A Description of the Dispersed Phase and a Parametric Study of Heat Transfer Results,” Two Phase Flow Heat Transfer, Proceedings of NATO Advanced Study Institute, Vol. 3, Washington, DC, pp. 1327–1346.
2.
Estes, K. A., 1994, “Critical Heat Flux in Spray Cooling and Jet Impingement Cooling of Small Targets,” Master’s Thesis, School of Mechanical Engineering, Purdue University, West Lafeyette, IN
3.
Hall
D. D.
, and
Mudawar
L.
,
1995
, “
Experimental and Numerical Study of Quenching Complex-Shaped Metallic Alloys With Multiple, Overlapping Sprays
,”
International Journal of Heat and Mass Transfer
, Vol.
38
, pp.
1201
–
1216
.
4.
Lefebvre, A. H., 1989, Atomization and Sprays, Hemisphere Publishing Corporation, New York.
5.
Monde
M.
,
Kusuda
H.
, and
Uehara
H.
,
1980
, “
Burnout Heat Flux in Saturated Forced Convection Boiling With Two or More Impinging Jets
,”
Transactions of JSME
, Vol.
46
, pp.
1834
–
1843
.
6.
Moriyama, A., Araki, K., Yamagami, M., and Mase, K., 1987, “Local Heat Transfer Coefficient in Spray Cooling a Hot Surface,” Proc. 15th Japanese Conference on Liquid Atomization and Spray Systems, Vol. 28, Tokyo, Japan, pp. 104–109.
7.
Mudawar
I.
, and
Valentine
W. S.
,
1989
, “
Determination of the Local Quench Curve for Spray-Cooled Metallic Surfaces
,”
Journal of Heat Treating
, Vol.
7
, pp.
107
–
121
.
8.
Mudawar
I.
, and
Deiters
T. A.
,
1994
, “
A Universal Approach to Predicting Temperature Response of Metallic Parts to Spray Quenching
,”
International Journal of Heat and Mass Transfer
, Vol.
37
, pp.
347
–
362
.
9.
Toda
S.
,
1972
, “
A Study in Mist Cooling
,”
Transactions of JSME
, Vol.
38
, pp.
581
–
588
.
10.
Watchers
L. H. J.
,
Smulders
L.
,
Vermeulen
J. R.
, and
Kleiweg
H. C.
,
1966
, “
The Heat Transfer From a Hot Wall to Impinging Mist Droplets in the Spheroidal State
,”
Chemical Engineering Science
, Vol.
21
, pp.
1231
–
1238
.
This content is only available via PDF.
Copyright © 1996
 by The American Society of Mechanical Engineers
You do not currently have access to this content.