Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406×2.032mm2 cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Features unique to two-phase micro-channel flow were identified and employed to validate key assumptions of an annular flow boiling model that was previously developed to predict pressure drop and heat transfer in two-phase micro-channel heat sinks. This earlier model was modified based on new findings from the adiabatic two-phase flow study. The modified model shows good agreement with experimental data for water-cooled heat sinks.

1.
Ghiaasiaan
,
S. M.
, and
Abdel-Khalik
,
S. I.
,
2001
, “
Two-Phase Flow in Microchannels
,”
Advances in Heat Transfer, Academic Press, New York
,
34
, pp.
145
254
.
2.
Bowers
,
M. B.
, and
Mudawar
,
I.
,
1994
, “
High Flux Boiling in Low Flow Rate, Low Pressure Drop Mini-Channel and Micro-Channel Heat Sinks
,”
Int. J. Heat Mass Transfer
,
37
, pp.
321
332
.
3.
Bowers
,
M. B.
, and
Mudawar
,
I.
,
1994
, “
Two-Phase Electronic Cooling using Mini-Channel and Micro-Channel Heat Sinks: Part 1-Design Criteria and Heat Diffusion Constraints
,”
ASME J. Electron. Packag.
,
116
, pp.
290
297
.
4.
Bowers
,
M. B.
, and
Mudawar
,
I.
,
1994
, “
Two-Phase Electronic Cooling using Mini-Channel and Micro-Channel Heat Sinks, Part 2: Flow Rate and Pressure Drop Constraints
,”
ASME J. Electron. Packag.
,
116
, pp.
298
305
.
5.
Peng
,
X. F.
, and
Wang
,
B. X.
,
1993
, “
Forced Convection and Flow Boiling Heat Transfer for Liquid Flowing through Microchannels
,”
Int. J. Heat Mass Transfer
,
36
, pp.
3421
3427
.
6.
Jiang
,
L.
,
Wong
,
M.
, and
Zohar
,
Y.
,
2001
, “
Forced Convection Boiling in a Microchannel Heat Sink
,”
J. Microelectromech. Syst.
,
10
, pp.
80
87
.
7.
Zhang, L., Koo, J. M., Jiang, L., Banerjee, S. S., Ashegi, M., Goodson, K. E., Santiago, J. G., Kenny, T. W., 2000, “Measurement and Modeling of Two-Phase Flow in Microchannels with Nearly-Constant Heat Flux Boundary Conditions,” Micro-Electro-Mechanical Systems (MEMS)-2000, A. Lee et al., eds., ASME, MEMS-Vol. 2, pp. 129–135.
8.
Hetsroni
,
G.
,
Mosyak
,
A.
,
Segal
,
Z.
, and
Ziskind
,
G.
,
2002
, “
A Uniform Temperature Heat Sink for Cooling of Electronic Devices
,”
Int. J. Heat Mass Transfer
,
45
, pp.
3275
3286
.
9.
Qu
,
W.
, and
Mudawar
,
I.
,
2003
, “
Flow Boiling Heat Transfer in Two-Phase Micro-Channel Heat Sinks-I. Experimental Investigation and Assessment of Correlation Methods
,”
Int. J. Heat Mass Transfer
,
46
, pp.
2755
2771
.
10.
Qu
,
W.
, and
Mudawar
,
I.
,
2003
, “
Flow Boiling Heat Transfer in Two-Phase Micro-Channel Heat Sinks-II. Annular Two-Phase Flow Model
,”
Int. J. Heat Mass Transfer
,
46
,
2773
2784
.
11.
Qu
,
W.
, and
Mudawar
,
I.
,
2003
, “
Measurement and Prediction of Pressure Drop in Two-Phase Micro-Channel Heat Sinks
,”
Int. J. Heat Mass Transfer
,
46
, pp.
2737
2753
.
12.
Hosler, E. R., 1968, “Flow patterns in High Pressure Two-Phase (Stream-Water) Flow with Heat Addition,” AIChE Symposium Series, Vol. 64, pp. 54–66.
13.
Wambsganss
,
M. W.
,
Jendrzejczyk
,
J. A.
, and
France
,
D. M.
,
1991
, “
Two-Phase Flow Patterns and Transition in a Small, Horizontal, Rectangular Channel
,”
Int. J. Heat Mass Transfer
,
17
, pp.
327
342
.
14.
Ali, M. I., and Kawaji, M., 1991, “The Effect of Flow Channel Orientation on Two-Phase Flow in a Narrow Passage between Flat Plates,” Proceedings of the 1991 ASME/JSME Thermal Engineering Joint Conference, J. R. Lloyd, Y. Kurosaki, eds., ASME, New York, N.Y., Vol. 2, pp. 183–190.
15.
Mishima
,
K.
,
Hibiki
,
T.
, and
Nishihara
,
H.
,
1993
, “
Some Characteristics of Gas-Liquid Flow in Narrow Rectangular Ducts
,”
Int. J. Multiphase Flow
,
19
, pp.
115
124
.
16.
Wilmarth
,
T.
, and
Ishii
,
M.
,
1994
, “
Two-Phase Flow Regimes in Narrow Rectangular Vertical and Horizontal Channels
,”
Int. J. Heat Mass Transfer
,
37
, pp.
1749
1758
.
17.
Fujita, H., Ohara, T., Hirota, M., and Furuta, H., 1995, “Gas-Liquid Flows in Flat Channels with Small Channel Clearance,” Advances in Multiphase Flow, A. Serizawa, T. Fukano, and J. Bataille, eds., Elsevier Science, New York, pp. 441–451.
18.
Xu
,
J. L.
,
Cheng
,
P.
, and
Zhao
,
T. S.
,
1999
, “
Gas-Liquid Two-Phase Flow Regimes in Rectangular Channels with Mini/Micro Gaps
,”
Int. J. Multiphase Flow
,
25
, pp.
411
432
.
19.
Mandhane
,
J. M.
,
Gregory
,
G. A.
, and
Aziz
,
K.
,
1974
, “
A Flow Pattern Map for Gas-Liquid Flow in Horizontal Pips
,”
Int. J. Multiphase Flow
,
1
, pp.
537
553
.
20.
Taitel
,
Y.
, and
Dukler
,
A. E.
,
1976
, “
A Model for Predicting Flow Regime Transitions in Horizontal and Near Horizontal Gas-Liquid Flow
,”
AIChE J.
,
22
, pp.
47
55
.
21.
Weisman
,
J.
,
Duncan
,
D.
,
Gibson
,
J.
, and
Crawford
,
T.
,
1979
, “
Effects of Fluid Properties and Pipe Diameter on Two-Phase Flow Patterns in Horizontal Line
,”
Int. J. Multiphase Flow
,
5
, pp.
437
462
.
22.
Cornwell, K., and Kew, P. A., 1993, “Boiling in Small Parallel Channels,” Energy Efficiency in Process Technology, P. A. Pilavachi, ed, Elsevier Science, New York, pp. 624–640.
23.
Suo
,
M.
, and
Griffith
,
P.
,
1964
, “
Two-Phase Flow in Capillary Tubes
,”
ASME J. Basic Eng.
,
86
, pp.
576
582
.
24.
Collier, J. G., and Thome, J. R., 1994, Convective Boiling and Condensation, 3rd edition, Oxford University Press, Oxford.
25.
Lockhart
,
R. W.
, and
Martinelli
,
R. C.
,
1949
, “
Proposed Correlation of Data for Isothermal Two-Phase, Two-Component Flow in Pipes
,”
Chem. Eng. Prog.
,
45
, pp.
39
48
.
26.
Martinelli
,
R. C.
, and
Nelson
,
D. B.
,
1948
, “
Prediction of Pressure Drop during Forced-Circulation Boiling of Water
,”
Trans. ASME
,
70
, pp.
695
702
.
27.
Chen
,
J. C.
,
1966
, “
Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow
,”
I&EC Process Design and Development
,
5
, pp.
322
329
.
28.
Edelstein
,
S.
,
Perez
,
A. J.
, and
Chen
,
J. C.
,
1984
, “
Analytic Representation of Convective Boiling Functions
,”
AIChE J.
,
30
, pp.
840
841
.
29.
Shah
,
M. M.
,
1976
, “
A New Correlation for Heat Transfer during Boiling Flow Through Pipes
,”
ASHRAE Trans.
,
82
, pp.
66
86
.
30.
Shah
,
M. M.
,
1982
, “
Chart Correlation for Saturated Boiling Heat Transfer: Equations and Further Study
,”
ASHRAE Trans.
,
88
, pp.
185
196
.
31.
Kandlikar
,
S. G.
,
1990
, “
A General Correlation for Saturated Two-Phase Flow Boiling Heat Transfer Inside Horizontal and Vertical Tubes
,”
ASME J. Heat Transfer
,
112
, pp.
219
228
.
32.
Steiner
,
D.
, and
Taborek
,
J.
,
1992
, “
Flow Boiling Heat Transfer in Vertical Tubes Correlated by an Asymptotic Model
,”
Heat Transfer Engineering
,
13
, pp.
43
69
.
You do not currently have access to this content.