Electrically Induced Shape Oscillation of Drops as a Means of Direct-Contact Heat Transfer Enhancement: Part 2—Heat Transfer

1988 ◽  
Vol 110 (3) ◽  
pp. 700-704 ◽  
Author(s):  
N. Kaji ◽  
Y. H. Mori ◽  
Y. Tochitani
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Electric Fields ◽  
Silicone Oil ◽  
Low Frequency ◽  
Transfer Enhancement ◽  
Contact Heat ◽  
Shape Oscillation ◽  
Sinusoidal Waveform ◽  
Water Drops

The heat transfer enhancement caused by the application of a low-frequency (1 ∼ 16 Hz) alternating field having the sinusoidal waveform has been studied experimentally with water drops in a medium of silicone oil. The heat transfer coefficient has been found to peak at three particular frequencies. The data newly obtained with the sinusoidal waveform are compared with earlier results obtained with electric fields having other waveforms. The waveform and the frequency that yield the largest enhancement of heat transfer are sought.

Heat Transfer Enhancement Due to Electrically Induced Resonant Oscillation of Drops

1985 ◽  
Vol 107 (4) ◽  
pp. 788-793 ◽  
Author(s):  
N. Kaji ◽  
Y. H. Mori ◽  
Y. Tochitani
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Silicone Oil ◽  
Low Frequency ◽  
Transfer Enhancement ◽  
Resonant Oscillation ◽  
Second Mode ◽  
Shape Oscillation ◽  
Enhancing Heat Transfer ◽  
Water Drops

By applying a low-frequency alternating field with a specially designed waveform, we succeeded in making water drops in a medium of silicone oil undergo a resonant shape oscillation of the second mode. The resonant oscillation was found to be quite effective for enhancing heat transfer between the medium and drops.

Flow and heat transfer enhancement in condensing water drops in steam flows

2014 ◽  
Vol 104 (7) ◽  
pp. 074101 ◽  
Author(s):  
Zhen Yang ◽  
Yuan-Yuan Duan ◽  
Zhao Zhu ◽  
Wei Gong ◽  
Xiao-Chen Ma ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Transfer Enhancement ◽  
Flow And Heat Transfer ◽  
Water Drops

Single-Phase Heat Transfer Enhancement Techniques in Microchannel and Minichannel Flows

2004 ◽  
Author(s):  
Mark E. Steinke ◽  
Satish G. Kandlikar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Electric Fields ◽  
Single Phase ◽  
Flow Boiling ◽  
Swirl Flow ◽  
Flow Transition ◽  
Transfer Enhancement ◽  
Compact Heat Exchangers ◽  
Chip Cooling

The single-phase heat transfer enhancement techniques are well established for conventional channels and compact heat exchangers. The major techniques include flow transition, breakup of boundary layer, entrance region, vibration, electric fields, swirl flow, secondary flow and mixers. In the present paper, the applicability of these techniques for single-phase flows in microchannels and minichannels is evaluated. The microchannel and minichannel single-phase heat transfer enhancement devices will extend the applicability of single-phase cooling for critical applications, such as chip cooling, before more aggressive cooling techniques, such as flow boiling, are considered.

Augmentation of Direct-Contact Heat Transfer to Drops with an Intermittent Electric Field

1980 ◽  
Vol 102 (1) ◽  
pp. 32-37 ◽  
Author(s):  
N. Kaji ◽  
Y. H. Mori ◽  
Y. Tochitani ◽  
K. Komotori
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Electric Field ◽  
Transfer Coefficient ◽  
Direct Contact ◽  
Silicone Oil ◽  
Duty Ratio ◽  
Contact Heat ◽  
Contact Heat Transfer ◽  
Water Drops

The characteristics of the augmentation technique previously proposed by the authors has been studied experimentally with water drops 3.9 to 5.9 mm in diameter rising in methylphenyl silicone oil. Each drop is subjected to an intermittent electric field applied periodically perpendicular to its trajectory, and the drop responds by periodic elongation in the direction of the field. The dependence of heat transfer coefficient on the strength, frequency and duty ratio of the field is presented and discussed.

Electrically Induced Shape Oscillation of Drops as a Means of Direct-Contact Heat Transfer Enhancement: Part 1—Drop Dynamics

1988 ◽  
Vol 110 (3) ◽  
pp. 695-699 ◽  
Author(s):  
N. Kaji ◽  
Y. H. Mori ◽  
Y. Tochitani
Keyword(s):  
Direct Contact ◽  
Low Frequency ◽  
Immiscible Liquid ◽  
Contact Heat ◽  
Resonant Oscillation ◽  
Liquid Drops ◽  
Contact Heat Exchange ◽  
Second Mode ◽  
Shape Oscillation ◽  
Sinusoidal Waveform

The shape oscillation of liquid drops passing through an immiscible liquid medium subject to a low-frequency (1 ∼ 16 Hz) alternating electric field having a sinusoidal waveform has been studied experimentally with the intention of investigating the enhancement of the direct-contact heat exchange between the two liquids. We have found that the field can induce, depending on its frequency, not only the resonant oscillation of the second mode of the drops, but also another peculiar oscillation that is related to the resonant oscillation of the third mode superposed on the second-mode oscillation.

Heat Transfer in Liquid-Liquid Taylor Flow in a Mini-Scale Tube With Constant Wall Temperature

2015 ◽  
Author(s):  
W. M. Adrugi ◽  
Y. S. Muzychka ◽  
K. Pope
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Wall Temperature ◽  
Silicone Oil ◽  
Transfer Enhancement ◽  
Constant Wall Temperature ◽  
Flow Rates ◽  
Taylor Flow ◽  
Low Viscosity ◽  
Wide Range

In this paper, heat transfer enhancement using liquid-liquid Taylor flow is examined. The experiments are conducted in mini-scale tubes with constant wall temperature. The segmented flow is created using several fractions of low viscosity silicone oil (1 cSt) and water for a wide range of flow rates and segment lengths. The variety of liquids and flow rates change the Prandtl, Reynolds, and capillary numbers. The dimensionless mean wall flux and the dimensionless thermal flow length are used to analyze the experimental heat transfer data. The comparison shows the heat transfer rate for Taylor flow is higher than in single-phase flow. The heat transfer enhancement occurs due to internal circulation in the fluid segments.

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