Numerical investigation of heat transfer enhancement and fluid flow characteristics in a microchannel heat sink with different wall/design configurations of protrusions/dimples

2019 ◽  
Vol 56 (1) ◽  
pp. 239-255 ◽  
Author(s):  
Muhammad Mohib Ur Rehman ◽  
Taqi Ahmad Cheema ◽  
Faraz Ahmad ◽  
Ahmad Abbas ◽  
Muhammad Sohail Malik
2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Ranjith Kumar Valaparla ◽  
Karthik Balasubramanian ◽  
Kupireddy Kiran Kumar

AbstractPurpose: Numerical investigation was carried out to study the hydro-thermal characteristics in circular wavy microchannels (CWMCs) with sidewall rib. Thermal resistance and pressure drop penalty were compared with sinusoidal wavy microchannels (SWMCs) design. Parametric study on sidewall rib was also carried to minimize the pressure drop penalty and to achieve lower thermal resistance. Introducing sidewall rib in the CWMCs leads to the formation of more Deans vortices. This leads to an effective fluid mixing and augments the convective heat transfer. Design methodology/approach: A computational solid domain was created in SOLIDWORKS and the fluid domain was produced by circular arc profile for the entire length of heat sink. 3-D numerical investigation was carried out using ANSYS FLUENT software. Created computational domain was imported into ANSYS WORKBENCH. Meshing was executed in ANSYS mesh module. The computational domains were meshed using hexahedral elements adopting match control on both sides of microchannel (MC). The numerical investigation was carried out in the Re range from 100 to 300 with constant heat flux (50 W/cm2) applied at the bottom of the channel. Heat transfer and fluid flow characteristics were explained with velocity vectors, velocity contours and temperature contours. Findings: From numerical studies, it is concluded that CWMC with sidewall rib width (0.15 mm) leads to 33.6 % lower thermal resistance than SWMC with pressure drop penalty. Originality/Value: Present study is useful to identify the optimum deign to augment the heat dissipation performance of microchannel heat sink.


2019 ◽  
Vol 160 ◽  
pp. 699-706 ◽  
Author(s):  
Mehedi Tusar ◽  
Kazi Ahmed ◽  
Muhammad Bhuiya ◽  
Palash Bhowmik ◽  
Mohammad Rasul ◽  
...  

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Y. J. Lee ◽  
P. S. Lee ◽  
S. K. Chou

Sectional oblique fins are employed in contrast to continuous fins in order to modulate flow in microchannel heat sink. The breakage of continuous fin into oblique sections leads to the reinitialization of both hydrodynamic and thermal boundary layers at the leading edge of each oblique fin, effectively reducing the thickness of boundary layer. This regeneration of entrance effect causes the flow to be always in a developing state thus resulting in better heat transfer. In addition, the presence of smaller oblique channels diverts a small fraction of flow into the adjacent main channels. The secondary flows thus created improve fluid mixing which serves to further enhance the heat transfer. Detailed numerical study on the fluid flow and heat transfer of this passive heat transfer enhancement technique provides insight to the local hydrodynamics and thermal development along the oblique fin. The uniquely skewed hydrodynamic and thermal profiles are identified as the key to the highly augmented and uniform heat transfer performance across the heat sink. The associated pressure drop penalty is much smaller than the achieved heat transfer enhancement, rendering it as an effective heat transfer enhancement scheme for single phase microchannel heat sink.


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