Abstract
Micro-channel heat sink (MCHS) has been extensively used in various electronic cooling fields. Double-layered MCHS, or DL-MCHS, is regarded as one effective technique for high-heat-flux transfer and is expected to meet the ever-increasing heat load requirement of future electronic device generations. In order to improve the cooling capacity, two new types of the MCHS, with a double-layered matrix structure (DL-M) and double-layered interlinked matrix structure (DL-IM) are proposed and investigated numerically. The two designs are compared with the traditional double-layered rectangular structure (DL-R) and the double-layered triangular structure (DL-T). Different properties of the heat sink are investigated to assess the overall heat transfer performance, for which coolant flow and heat transfer are both evaluated. The numerical results reveal that the periodical slot subchannel in the matrix has a significant effect on fluid flow for heat transfer. In comparison to the DL-R and the DL-T, the DL-M and DL-IM realize a much lower pressure drop and temperature rise at the base surface and also have higher Nusselt number and secondary flow intensity, therefore, manifesting better overall thermal performance. In the DL-M and DL-IM, the coolant flows along the periodical subchannel in one layer and is redirected into the second layer with vortices being induced. The vortices promote the coolant mixing and enhance the mass and heat transfer. These geometric design strategies can provide references for wide heat sink applications.
Highlights
With the rapid development of micro-electro-mechanical systems (MEMSs) in the past decades, the heat generation in many compact electronic devices can exceed 106 W/m2 [1]
In this paper, inspired by the trailing-edge cooling system for gas turbines [24,25], we proposed two microchannel heat sink (MCHS) structures with relatively simple configurations, namely the double-layered matrix (DL-M) and the double-layered interlinked-matrix (DL-IM) as shown in Figure 1a and b
The friction factor of the double-layered rectangular structure (DL-R) structure is calculated with the above numerical method and compared with that derived from the theoretical model expressed in Equation (7) for validation purposes
Summary
With the rapid development of micro-electro-mechanical systems (MEMSs) in the past decades, the heat generation in many compact electronic devices can exceed 106 W/m2 [1]. Wei et al [3] numerically investigated the double-layered rectangular microchannel structure with a coolant in parallel flow arrangement They found the required pumping power and flow rate in this condition was lower than that for SL-MCHS. Zhai et al [14] researched three other kinds of DL-MCHS with triangular rips and triangular cavities considering the field synergy principle and secondary flow characters They concluded that the arrangement of cavities and ribs has a great impact on flow friction and heat transfer and pointed out there is a large potential to enhance the convective heat transfer in double-layered microchannels. To consider the coolant flow and heat transfer systematically, the maximum and average temperature on the base surface, thermal resistance, pumping power, Nusselt number, thermal-enhanced factor, and secondary flow intensity are Micromachines 2020, 11, 146 investigated as the criteria to evaluate the heat transferred performance. We designed two novel double-layered matrix microchannels and evaluated the MCHS by the above-mentioned criteria
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