Thermal Performance of Microchannels With Dimples for Electronics Cooling

2013 ◽  
Author(s):  
Hui Lu ◽  
Liang Gong ◽  
Minghai Xu
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Integrated Circuits ◽  
Heat Sink ◽  
Electronics Cooling ◽  
Cooling Capacity ◽  
Constant Heat Flux ◽  
Microchannel Heat Sink ◽  
Transfer Enhancement ◽  
Different Types

The thermal management of integrated circuits becomes more and more serious since the density of transistors grows gradually. Recently, a new cooling method is dedicated to develop microchannel heat sink with high integrated and high cooling efficiency. In view of above purpose, the heat transfer enhancement and pressure drop reduction in microchannel with dimples are investigated in this paper. A single module of 1mm×1mm×20mm with a microchannel was employed, which hydraulic diameter and aspect ratio are 500 μm and 2:1 respectively. For replacing the running integrated circuits, a constant heat flux of 1W/mm2 was arranged on the bottom of the heat sink. Six different types of microchannels with dimples were designed and numerically studied under the condition of laminar flow. The results show that dimple could enhance heat transfer and decrease flow resistance under the condition of laminar flow. Compared with traditional microchannel heat sink, dimple-microchannel heat sink has stronger cooling capacity, could be an attractive choice for cooling of future microelectronics.

Design of a Microfin Array Heat Sink Using Flow-Induced Vibration to Enhance the Heat Transfer Rate in the Laminar Flow Regime

2001 ◽  
Author(s):  
Jeung Sang Go ◽  
Geunbae Lim ◽  
Hayong Yun ◽  
Sung Jin Kim ◽  
Inseob Song
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Heat Transfer Enhancement ◽  
Flow Regime ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
Transfer Enhancement ◽  
Air Velocity ◽  
Flow Induced Vibration

Abstract This paper presented design guideline of the microfin array heat sink using flow-induced vibration to increase the heat transfer rate in the laminar flow regime. Effect of the flow-induced vibration of a microfin array on heat transfer enhancement was investigated experimentally by comparing the thermal resistances of the microfin array heat sink and those of a plain-wall heat sink. At the air velocities of 4.4m/s and 5.5 m/s, an increase of 5.5% and 11.5% in the heat transfer rate was obtained, respectively. The microfin flow sensor also characterized the flow-induced vibration of the microfin. It was determined that the microfin vibrates with the fundamental natural frequency regardless of the air velocity. It was also shown that the vibrating displacement of the microfin is increased with increasing air velocity and then saturated over a certain value of air velocity. Based on the numerical analysis of the temperature distribution resulted from microfin vibration and experimental results, a simple heat transfer model (heat pumping model) was proposed to understand the heat transfer mechanism of a microfin array heat sink. Under the geometric and structural constraints, the maximum heat transfer enhancement was obtained at the intersection of the minimum thickness of the microfin and constraint of the bending angle.

Heat transfer enhancement in microchannel heat sink using hybrid technique of ribs and secondary channels

2017 ◽  
Vol 114 ◽  
pp. 640-655 ◽  
Author(s):  
Ihsan Ali Ghani ◽  
Nor Azwadi Che Sidik ◽  
Rizal Mamat ◽  
G. Najafi ◽  
Tan Lit Ken ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Sink ◽  
Hybrid Technique ◽  
Microchannel Heat Sink ◽  
Transfer Enhancement

Heat Transfer Enhancement in a Microchannel Heat Sink with Trapezoidal Cavities on the Side Walls

2016 ◽  
Vol 819 ◽  
pp. 127-131
Author(s):  
Navin Raja Kuppusamy ◽  
N.N.N. Ghazali ◽  
Saidur Rahman ◽  
M.A. Omar Awang ◽  
Hussein A. Mohammed
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Fluid Mixing ◽  
Microchannel Heat Sink ◽  
Transfer Enhancement ◽  
Side Walls

The present study focuses on the numerical study of thermal and flow characteristics in a microchannel heat sink with alternating trapezoidal cavities in sidewall (MTCS). The effects of flow rate and heat flux on friction factor and Nusselt are presented. The results showed considerable improvement heat transfer performance micro channel heat sink with alternating trapezoidal cavities in sidewall with an acceptable pressure drop. The heat transfer rate has improved in the cavity area due the greater fluid mixing in fluid vortices and thermal boundary layer disruption. The slipping over the reentrant cavities and pressure gain reduces pressure drop appears as the reason behind of only minor pressure drop due to the cavities.

Enhanced Thermal Transport in Microchannel Using Oblique Fins

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Y. J. Lee ◽  
P. S. Lee ◽  
S. K. Chou
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Transfer Enhancement ◽  
Heat Sink ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Working Fluid ◽  
Microchannel Heat Sink ◽  
Transfer Enhancement ◽  
Microchannel Heat Sinks

Sectional oblique fins are employed, in contrast to continuous fins in order to modulate the flow in microchannel heat sinks. The breakage of a continuous fin into oblique sections leads to the reinitialization of the thermal boundary layer at the leading edge of each oblique fin, effectively reducing the boundary layer thickness. This regeneration of entrance effects causes the flow to always be in a developing state, thus resulting in better heat transfer. In addition, the presence of smaller oblique channels diverts a small fraction of the flow into adjacent main channels. The secondary flows created improve fluid mixing, which serves to further enhance heat transfer. Both numerical simulations and experimental investigations of copper-based oblique finned microchannel heat sinks demonstrated that a highly augmented and uniform heat transfer performance, relative to the conventional microchannel, is achievable with such a passive technique. The average Nusselt number, Nuave, for the copper microchannel heat sink which uses water as the working fluid can increase as much as 103%, from 11.3 to 22.9. Besides, the augmented convective heat transfer leads to a reduction in maximum temperature rise by 12.6 °C. The associated pressure drop penalty is much smaller than the achieved heat transfer enhancement, rendering it as an effective heat transfer enhancement scheme for a single-phase microchannel heat sink.

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