Onset of nucleate boiling and onset of flow instability in uniformly heated microchannels with subcooled water flow were experimentally investigated using 22-cm long tubular test sections, 1.17 mm and 1.45 mm in diameter, with a 16-cm long heated length. Important experimental parameter ranges were: 3.44 to 10.34 bar channel exit pressure; 800 to 4500 kg/m2s mass flux (1 to 5 m/s inlet velocity); 0 to 4.0 MW/m2 channel wall heat flux; and 7440–33,000 Peclet number at the onset of flow instability. Demand curves (pressure drop versus mass flow rate curves for fixed wall heat flux and channel exit pressure) were generated for the test sections, and were utilized for the specification of the onset of nucleate boiling and the onset of flow instability points. The obtained onset of nucleate boiling and onset of flow instability data are presented and compared with relevant widely used correlations. [S0022-1481(00)02101-0]

1.
Boure´
,
J. A.
,
Bergles
,
A. E.
, and
Tong
,
L. S.
,
1973
, “
Review of Two-Phase Flow Instability
,”
Nucl. Eng. Desned.
,
25
, pp.
165
192
.
2.
Ishii, M., 1976, “Study of Flow Instabilities in Two-Phase Mixtures,” Argonne National Laboratory Report, ANL-76-23.
3.
Bergles, A. E., 1977, “Review of Instabilities in Two-Phase Systems,” Two-Phase and Heat Transfer, 2, S. Kakac and F. Mayinger, eds., Hemisphere, Washington, DC, pp. 383–422.
4.
Yadigaroglu, G., 1981, “Two-Phase Flow Instabilities and Propagation Phenomena,” Thermohydraulics of Two-Phase Systems for Individual Design and Nuclear Engineering, M. Delhaye, M. Giot, and L. M. Riethmuller, eds., Hemisphere, Washington, DC, pp. 353–403.
5.
Bergles
,
A. E.
, and
Rohsenow
,
W. M.
,
1964
, “
The Determination of Forced-Convection Surface Boiling Heat Transfer
,”
ASME J. Heat Transfer
,
C86
, pp.
365
372
.
6.
Saha, P., and Zuber, N., 1974, “Point of Net Vapor Generation and Vapor Void Fraction in Subcooled Boiling,” Proceedings of the 5th International Heat Transfer Conference, Tokyo, Japan, pp. 175–179.
7.
U¨nal
,
H. C.
,
1975
, “
Determination of the Initial Point of Net Vapor Generation in Flow Boiling Systems
,”
Int. J. Heat Mass Transf.
,
18
, pp.
1095
1099
.
8.
Levy
,
S.
,
1967
, “
Forced Convection Subcooled Boiling: Prediction of Vapor Volumetric Fraction
,”
Int. J. Heat Mass Transf.
,
28
, pp.
1116
1129
.
9.
Staub
,
F. W.
,
1975
, “
The Void Fraction in Subcooled Boiling: Prediction of the Initial Point of Net Vapor Generation
,”
Int. J. Heat Mass Transf.
,
8
, pp.
1095
1099
.
10.
Rogers
,
J. T.
,
Salcudean
,
M.
,
Abdullah
,
Z.
,
McLeod
,
D.
, and
Poirier
,
D.
,
1987
, “
The Onset of Significant Void in Up-Flow Boiling of Water at Low Pressures and Velocities
,”
Int. J. Heat Mass Transf.
,
30
, pp.
2247
2260
.
11.
Triplett
,
K. A.
,
Ghiaasiaan
,
S. M.
,
Abdel-Khalik
,
S. I.
, and
Sadowski
,
D. L.
,
1999
, “
Gas-Liquid Two-Phase Flow in Microchannels, Part I: Two-Phase Flow Patterns
,”
Int. J. Multiphase Flow
,
25
, pp.
377
394
.
12.
Triplett
,
K. A.
,
Ghiaasiaan
,
S. M.
,
Abdel-Khalik
,
S. I.
,
LeMouel
,
A.
, and
McCord
,
B. N.
,
1999
, “
Gas-Liquid Two-Phase Flow in Microchannels, Part II: Void Fraction and Pressure Drop
,”
Int. J. Multiphase Flow
,
25
, pp.
395
410
.
13.
Vandervort, C. L., Bergles, A. E., and Jensen, M. K., 1992, “Heat Transfer Mechanisms in Very High Heat Flux Boiling,” Fundamentals of Subcooled Flow Boiling, ASME, New York, pp. 1–9.
14.
Peng
,
X. F.
, and
Wang
,
B. X.
,
1993
, “
Forced Convection and Flow Boiling Heat Transfer for Liquids Flowing Through Microchannels
,”
Int. J. Heat Mass Transf.
,
36
, pp.
3421
3427
.
15.
Peng, X. F., and Wang, B. X., 1994, “Liquid Flow and Heat Transfer in Microchannels With/Without Phase Change,” Proceedings of the 10th International Heat Transfer Conference, 5, pp. 159–177.
16.
Bevington, P. R., and Robinson, D. K., 1992, Data Reduction and Error Analysis for the Physical Sciences, 2nd Ed., McGraw-Hill, New York.
17.
Kennedy, J. E., 1997, “Onset of Flow Instability in Uniformly Heated Microchannels,” M.S. thesis, Georgia Institute of Technology, Atlanta, GA.
18.
Idelchick, I. E., 1994, Handbook of Hydraulic Resistances, 3rd Ed., CRC Press, London.
19.
Inasaka
,
F.
,
Nariai
,
H.
, and
Shimura
,
T.
,
1989
, “
Pressure Drops in Subcooled Flow Boiling in Narrow Tubes
,”
Heat Transfer–Japanese Research
,
18
, pp.
70
82
.
20.
Dittus
,
P. W.
, and
Boelter
,
L. M. K.
,
1930
, “
Heat Transfer in Automobile Radiators of Tubular Type
,”
Univ. of CA Pub. Engng.
2
, No.
13
, pp.
443
461
.
21.
Hino
,
R.
, and
Ueda
,
T.
,
1985
, “
Studies on Heat Transfer and Flow Characteristics in Subcooled Flow Boiling—Part I: Boiling Characteristics
,”
Int. J. Multiphase Flow
,
11
, pp.
29
281
.
22.
Johnston, J. S., 1989, “Subcooled Boiling of Downward Flow in a Vertical Annulus,” ASME Proceedings of the National Heat Transfer Conference, ASME, New York, pp. 149–156.
23.
Hu
,
L. W.
, and
Pan
,
C.
,
1995
, “
Prediction of Void Fraction in Convective Subcooled Boiling Channels Using a One-Dimensional Two-Fluid Model
,”
ASME J. Heat Transfer
,
117
, pp.
799
803
.
24.
Forgan, R., and Whittle, R. H., 1966, “Pressure Drop Characteristics for the Flow of Subcooled Water at Atmospheric Pressure in Narrow Heated Channels,” UK Atomic Energy Research Establishment Report AERE-M 1739.
You do not currently have access to this content.