NUMERICAL SIMULATION OF HEAT TRANSFER CHARACTERISTIC OF DOUBLE-LAYER Y-SHAPED MICROCHANNEL HEAT SINK

2018 ◽  
Author(s):  
Zhijian Duan ◽  
Gongnan Xie ◽  
Guohua Zhang ◽  
Xin Jin
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Double Layer ◽  
Heat Sink ◽  
Heat Transfer Characteristic ◽  
Transfer Characteristic ◽  
Microchannel Heat Sink

Effect of Microfins on Thermal Performance of Microchannel Using CFD

2018 ◽  
Vol 7 (3.14) ◽  
pp. 1
Author(s):  
Wei Long Yeo ◽  
Kim Ho Yeap ◽  
Koon Chun Lai ◽  
Pei Song Chee ◽  
Kok Seng Ong
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Sink ◽  
Heat Transfer Characteristic ◽  
Thermal Boundary Layer ◽  
Reynold Number ◽  
Transfer Characteristic ◽  
Microchannel Heat Sink ◽  
Flow And Heat Transfer ◽  
Different Types

In the present study, the fluid flow and heat transfer characteristic of microchannel heat sink with microfins are studied numerically at Reynold number ranging from 400 to 1200. The influence of microfins on the Nusselt number and pressure drop are investigated. Five different types of microfins namely cylindrical microfins (Case A), diverge cylindrical microfins (Case B), diverge cylindrical microfins with semi-circle rib (Case C), diverge cylindrical microfins with rectangular rib (Case D) and diverge cylindrical microfins with triangular rib (Case E) are designed. A comparative analysis of these five types of microfins with bare microchannel has been conducted. The result highlighted the extended microfins augmented the heat transfer characteristic by disrupt the thermal boundary layer. The overall thermal performances of microchannel heat sink with microfins are 1.1 – 1.47 times higher compared to bare microchannel.  

Effects of passage divider and packed brass beads on heat transfer characteristic of the pin-fin heat sink by water cooling

2019 ◽  
Vol 56 (5) ◽  
pp. 1429-1441
Author(s):  
Tzer-Ming Jeng ◽  
Sheng-Chung Tzeng ◽  
Ching-Wen Tseng ◽  
Chia-Hung Chang
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Transfer Characteristic ◽  
Transfer Characteristic ◽  
Water Cooling ◽  
Pin Fin

NUMERICAL SIMULATION OF FLOW AND HEAT TRANSFER CHARACTERISTIC OF 4K REGENERATORS AT HIGH FREQUENCY

2012 ◽  
Vol 19 ◽  
pp. 406-416
Author(s):  
ZHUOPEI LI ◽  
YANLONG JIANG ◽  
ZHIHUA GAN ◽  
LIMIN QIU
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
High Frequency ◽  
Heat Transfer Characteristic ◽  
Pressure Ratio ◽  
Transfer Characteristic ◽  
Ideal Gas ◽  
Maximum Pressure ◽  
Pulse Tube ◽  
Flow And Heat Transfer

Regenerator is a key component for all regenerative cryocoolers. 4K regenerative cryocoolers can be applied to provide cooling for low temperature superconductors, space and military infrared detectors, and medical examination etc. Stirling type pulse tube cryocoolers (SPTC), one type of regenerative cryocoolers, operate at high frequencies. As a result, SPTCs have the advantage of compact structure and low weight compared with G-M type pulse tube cryocoolers operating at low frequencies. However, as the frequency increase the thermal penetration depth of helium gas in the regenerator is greatly reduced which makes the heat transfer between the gas and the regenerator worse. In order to improve the heat transfer efficiency, regenerator materials with smaller hydraulic diameters are used. Therefore the flow resistance between the gas and the regenerator material will increase leading to larger pressure drop from the hot end to the cold end of the regenerator. The cooling performance is deteriorated due to the decreased pressure ratio (maximum pressure divided by minimum pressure) at the cold end. Also, behavior of helium at 4K deviates remarkably from that of ideal gas which has a significant influence both the flow and heat transfer characteristic within a regenerator. In this paper numerical simulation on the behavior of a 4K regenerator at high frequency is carried out to provide guidance for the optimization of the flow and heat transfer performance within a regenerator. Thermodynamic analysis of effect of the non-ideal gas behavior of helium at 4K on 4K regenerator at high frequency is investigated.

scholarly journals Performance Improvement of a Double-Layer Microchannel Heat Sink via Novel Fin Geometry—A Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3585
Author(s):  
Yong-Dong Zhang ◽  
Miao-Ru Chen ◽  
Jung-Hsien Wu ◽  
Kuo-Shu Hung ◽  
Chi-Chuan Wang
Keyword(s):  
Heat Transfer ◽  
Double Layer ◽  
Heat Sink ◽  
Numerical Study ◽  
Lower Layer ◽  
High Heat ◽  
Microchannel Heat Sink ◽  
Fin Efficiency ◽  
High Heat Transfer ◽  
Improve Heat Transfer

This study proposes a novel design having dense fins with lesser thickness at the upper layer and comparatively spare fins with greater thickness in the lower layer to further improve the overall thermal performance of a double-layer microchannel heat sink. The design can effectively direct more low temperature fluid flow toward the lower layer to improve heat transfer while the sparse fin structure at low layer can ease pressure drop penalty. At the same time, the thicker fins at the lower layer ensure higher fin efficiency to facilitate high heat transfer. Parametric and detailed analysis is conducted for the proposed double-layer microchannel heat sink in comparison with the traditional one. After optimization, the thermal resistance of the proposed double-layer microchannel heat sink at the same pumping power is found to be reduced by 9.42% when compared to the traditional double-layer microchannel heat sink. Yet at the same Reynolds number, the Nusselt number of the proposed design exceeds the traditional value by 13%.

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