HEAT TRANSFER AND LIQUID MOTION OF FORCED CONVECTIVE BOILING IN A MINI-TUBE FOR AQUEOUS SOLUTIONS WITH NONLINEAR SURFACE ENERGY

2007 ◽  
Vol 19 (3) ◽  
pp. 225-240 ◽  
Author(s):  
N. Ono ◽  
T. Yoshida ◽  
M. Shoji ◽  
F. Takemura ◽  
T. H. Yen
Keyword(s):  
Heat Transfer ◽  
Surface Energy ◽  
Aqueous Solutions ◽  
Liquid Motion ◽  
Convective Boiling ◽  
Nonlinear Surface

The Aqueous Solutions With Nonlinear Surface Energy and Their Application to Flow Boiling in a Mini/Micro Tube

2007 ◽  
Author(s):  
Naoki Ono ◽  
Takahiro Yoshida ◽  
Masahiro Shoji ◽  
Shotaro Nishiguchi
Keyword(s):  
Heat Transfer ◽  
Surface Tension ◽  
Aqueous Solutions ◽  
Flow Boiling ◽  
Test Fluid ◽  
Small Scale ◽  
Temperature Dependency ◽  
Micro Channel ◽  
Liquid Motion ◽  
Nonlinear Solution

The temperature dependency of surface tension of aqueous solutions of some alcohol such as butanol and pentanol behaves in a nonlinear manner. Namely, the value of surface tension increases from some temperature when the solution is heated. Since this was discovered about 30 years ago, several experimental studies were done about the liquid motion focusing on the difference from the normal fluids. At the same time several ideas have been attempted in the application to heat pipes and so on to promote the heat transfer. The direction of thermocapillary force in liquid film of the nonlinear solution on a heated surface acts in the same direction to solute Marangoni force. This characteristic will be much marked in small scale systems such as mini/micro channels. In this talk the author surveys the research about the special aqueous solutions and their applications until now. Moreover, the author will report the new measurement results about the nonlinearity of the temperature dependency of the surface tension of the solutions. Also the author will present the result of flow boiling and the liquid motion when the nonlinear aqueous solution was used as test fluid for mini channel of 1 mm ID. The mini/micro channel was a single quartz tube with thin film heater coated on its outer surface. When the channel was mini channel of 1 mm ID, the dryout position was not much different from the case when pure water was used as test fluid. But the liquid motion was much different. The experiments when the channel was smaller micro channel (for example, 500 μm ID), are being done in the authors’ laboratory. Moreover, the author is also doing the experiments about the boiling heat transfer in regard to the increase of CHF when the nonlinear solution was used as test fluid.

Heat transfer in liquid motion through a rectangular channel

1993 ◽  
Vol 64 (5) ◽  
pp. 415-421
Author(s):  
Yu. V. Sharvin ◽  
V. G. Rifert ◽  
I. D. Iliyev
Keyword(s):  
Heat Transfer ◽  
Rectangular Channel ◽  
Liquid Motion

THE STABILITY ANALYSIS OF HEAT TRANSFER IN SATURATED LIQUID FILM OF THE SPECIAL MATERIALS

2005 ◽  
Vol 19 (28n29) ◽  
pp. 1547-1550
Author(s):  
YOULIANG CHENG ◽  
XIN LI ◽  
ZHONGYAO FAN ◽  
BOFEN YING
Keyword(s):  
Heat Transfer ◽  
Differential Equation ◽  
Surface Tension ◽  
Stability Analysis ◽  
Liquid Film ◽  
Nonlinear Relationship ◽  
Saturated Liquid ◽  
Nonlinear Surface ◽  
Isothermal Wall ◽  
The Stability

Representing surface tension by nonlinear relationship on temperature, the boundary value problem of linear stability differential equation on small perturbation is derived. Under the condition of the isothermal wall the effects of nonlinear surface tension on stability of heat transfer in saturated liquid film of different liquid low boiling point gases are investigated as wall temperature is varied.

Reduced Pressure Boiling Heat Transfer in Rectangular Microchannels With Interconnected Reentrant Cavities

2005 ◽  
Vol 127 (10) ◽  
pp. 1106-1114 ◽  
Author(s):  
Ali Koşar ◽  
Chih-Jung Kuo ◽  
Yoav Peles
Keyword(s):  
Heat Transfer ◽  
Heat Fluxes ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Convective Boiling ◽  
Reduced Pressure ◽  
Exit Pressure ◽  
Mass Fluxes ◽  
Mechanism Transition ◽  
Two Phase Heat Transfer

Boiling flow of deionized water through 227μm hydraulic diameter microchannels with 7.5μm wide interconnected reentrant cavities at 47 kPa exit pressure has been investigated. Average two-phase heat transfer coefficients have been obtained over effective heat fluxes ranging from 28 to 445W∕cm2 and mass fluxes from 41 to 302kg∕m2s. A map is developed that divides the data into two regions where the heat transfer mechanisms are nucleation or convective boiling dominant. The map is compared to similar atmospheric exit pressure data developed in a previous study. A boiling mechanism transition criterion based on the Reynolds number and the Kandlikar k1 number is proposed.

Forced Convective Boiling of Refrigerant HCFC123 in a Mini-Tube

2010 ◽  
Author(s):  
Koichi Araga ◽  
Keisuke Okamoto ◽  
Keiji Murata
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flux ◽  
Pool Boiling ◽  
Constant Heat Flux ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Convective Boiling ◽  
Frictional Pressure Drop ◽  
Heat Transfer Coefficients

This paper presents an experimental investigation of the forced convective boiling of refrigerant HCFC123 in a mini-tube. The inner diameters of the test tubes, D, were 0.51 mm and 0.30 mm. First, two-phase frictional pressure drops were measured under adiabatic conditions and compared with the correlations for conventional tubes. The frictional pressure drop data were lower than the correlation for conventional tubes. However, the data were qualitatively in accord with those for conventional tubes and were correlated in the form φL2−1/Xtt. Next, heat transfer coefficients were measured under the conditions of constant heat flux and compared with those for conventional tubes and for pool boiling. The heat transfer characteristics for mini-tubes were different from those for conventional tubes and quite complicated. The heat transfer coefficients for D = 0.51 mm increased with heat flux but were almost independent of mass flux. Although the heat transfer coefficients were higher than those for a conventional tube with D = 10.3 mm and for pool boiling in the low quality region, they decreased gradually with increasing quality. The heat transfer coefficients for D = 0.30 mm were higher than those for D = 0.51 mm and were almost independent of both mass flux and heat flux.

Surface energy effect on boiling heat transfer

2005 ◽  
Vol 41 (12) ◽  
pp. 1043-1047 ◽  
Author(s):  
Atul P. Patil ◽  
Vijaya C. B. Vittala
Keyword(s):  
Heat Transfer ◽  
Surface Energy ◽  
Boiling Heat Transfer ◽  
Energy Effect ◽  
Surface Energy Effect
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