Heat Transfer of Two-Phase Impinging Jet: Heat Transfer Enhancement

2004 ◽  
Author(s):  
Masahiro Osakabe ◽  
Sachiyo Horiki
Keyword(s):  
Heat Transfer ◽  
Pressure Fluctuation ◽  
Single Phase ◽  
Degradation Mechanism ◽  
Copper Surface ◽  
Transfer Enhancement ◽  
Two Phase ◽  
Enhancement Of Heat Transfer ◽  
Inner Diameter ◽  
Two Phase Heat Transfer

To study the enhancement and degradation mechanism of impinging two-phase heat transfer, air/water two-phase jet was applied on the cooling of copper surface of 30 mm in diameter. The two-phase jet impinged vertically on the horizontal heat transfer surface from capillary nozzle holes of 2, 4 and 6 mm in inner diameter. The non-dimensional heat transfer coefficient (HTC) was defined as the experimental HTC divided with the predictive HTC where the superficial two-phase velocity jG+jL and the physical properties of water were used in the empirical HTC correlation for single-phase flow. The larger non-dimensional HTC and stagnation pressure fluctuation were obtained with the nozzle of larger diameter. The larger nozzle could provide the more significant enhancement of heat transfer and pressure fluctuation with an addition of air. It was considered that the enhancement of heat transfer was due to the stimulation of thermal boundary layer with an addition of air.

MICROSCALE TWO PHASE HEAT TRANSFER ENHANCEMENT IN POROUS STRUCTURES

Equipment ◽  
2006 ◽  
Author(s):  
Leonid L. Vasiliev ◽  
A. Zhuravlyov ◽  
A. Shapovalov ◽  
L. L. Vasiliev, Jr
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Porous Structures ◽  
Transfer Enhancement ◽  
Two Phase ◽  
Two Phase Heat Transfer

Two-Phase Heat Transfer Enhancement

2020 ◽  
Author(s):  
Sujoy Kumar Saha ◽  
Hrishiraj Ranjan ◽  
Madhu Sruthi Emani ◽  
Anand Kumar Bharti
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Transfer Enhancement ◽  
Two Phase ◽  
Two Phase Heat Transfer

Two-Phase Heat Transfer Enhancement on Sintered Copper Microparticle Porous Structure Module Surface

2009 ◽  
Author(s):  
Calvin H. Li ◽  
Ting Li ◽  
Brian Kanney
Keyword(s):  
Heat Transfer ◽  
Porous Structure ◽  
Bubble Dynamics ◽  
Transfer Enhancement ◽  
Enhanced Heat Transfer ◽  
Two Phase ◽  
Sintered Copper ◽  
Theoretical Predictions ◽  
Heat Transfer Capacity ◽  
Two Phase Heat Transfer

An experimental study of the pool boiling two-phase heat transfer on a sintered Cu microparticle porous structure module surface is conducted. Enhanced heat transfer capacity of this module surface has been reported, and the boiling characteristics have been investigated. The bubble dynamics and nucleate size distribution have been compared to the theoretical predictions, and the speculated mechanisms have been discussed.

Two-Phase Heat Transfer Performance of Dielectric Fluid HFE-7100 Within Multiport Microchannel

2008 ◽  
Author(s):  
Lung-Yi Lin ◽  
Yeau-Ren Jeng ◽  
Chi-Chuan Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Single Phase ◽  
Heat Transfer Performance ◽  
Convective Heat Transfer Coefficient ◽  
Dielectric Fluid ◽  
Transfer Performance ◽  
Two Phase ◽  
Two Phase Heat Transfer

This study presents convective single-phase and boiling two-phase heat transfer performance of HFE-7100 coolant within multi-port microchannel heat sinks. The corresponding hydraulic diameters are 450 and 237 μm, respectively. For single-phase results, the presence of inlet/outlet locations inevitably gives rise to considerable increase of total pressure drop of a multi-port microchannel heat sink whereas has virtually no detectable influence on overall heat transfer performance provided that the effect of entrance has been accounted for. The convective boiling heat transfer coefficient for the HFE-7100 coolant shows a tremendous drop when vapor quality is above 0.6. For Dh = 450 μm, it is found that the mass flux effect on the convective heat transfer coefficient is rather small.

Microjet Impingement Boiling on a Structured-Porous Surface

2012 ◽  
Author(s):  
Zenghui Zhao ◽  
Yoav Peles ◽  
Michael K. Jensen
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Performance Enhancement ◽  
Copper Surface ◽  
Wire Mesh ◽  
Porous Surface ◽  
Two Phase ◽  
Base Surface ◽  
Mesh Screen ◽  
Two Phase Heat Transfer

Using single/multiple layers of highly conductive metallic wire mesh screen bonded to a plain heat transfer base surface, the two-phase heat transfer performance of a microjet impinging onto a porous coated copper surface was studied. Experiments were conducted at three different flow rates of water under atmospheric pressure. For comparison, experiments of jet impinging on a plain copper surface were also conducted. The results show that a base surface heat flux of 289W/cm2 is reached at a superheat of 7.9K and a jet Reynolds number of 5000 with a four-layer 200-mesh test article. Compared to jet impinging on a plain copper surface under similar working conditions, a 248% performance enhancement is obtained with the porous surface.

Experimental Modeling of Light Phase Effect on Heat Transfer in Rod Bundle

2013 ◽  
Author(s):  
O. N. Kashinsky ◽  
P. D. Lobanov ◽  
A. S. Kurdyumov ◽  
N. A. Pribaturin ◽  
S. E. Volkov
Keyword(s):  
Heat Transfer ◽  
Single Phase ◽  
Phase Distribution ◽  
Transfer Enhancement ◽  
Light Phase ◽  
Two Phase ◽  
Injection Point ◽  
Rod Bundle ◽  
Fraction Distribution ◽  
Gas Liquid Flow

Experiments in two-phase gas-liquid flow in a vertical bundle of rods were performed. The void fraction distribution and heat transfer from heated central rod were considered. Comparisons for cases of single phase and two-phase flows are presented. Gas addition to the flow results in heat transfer enhancement. The position of gas injection point plays a significant role on heat transfer characteristics. A non uniform gas phase distribution around the central rod of the bundle was obtained.

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