Ghorbani Nima, Targhi Mohammad Zabetian, Heyhat Mohammad Mahdi, Alihosseini Yousef
Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran.
Sci Rep. 2022 Apr 7;12(1):5882. doi: 10.1038/s41598-022-09859-6.
A numerical study was conducted to investigate the ability of wavy microchannels to damp the temperature fluctuations generates in electronic devices. Five wavy patterns are considered with the amplitude and wavelength in the ranges of 62.5 to 250 μm and 1250 to 5000 μm, respectively to study the effect of governing phenomena of flow within wavy patterns on thermal-hydraulic performance. The flow regime is laminar and the Reynolds number is in the range of 300 to 900, and a relatively high heat flux of 80 W/cm is applied to the microchannels substrate. Also, variable flux condition is studied for heat fluxes of 80, 120, 160, 200, and 240 W/cm and for the most efficient wavy and straight microchannels. Results showed that the geometries with larger amplitude to wavelength ratio have a lower radius of curvature and larger Dean number, and as a result of transverse flow (secondary flow) amplification, they have enhanced heat transfer. Also, by comparing the ratio of the transverse velocity components to the axial component, it was found that by decreasing the radius of curvature and increasing the Dean number, transverse velocity increases, which intensifies the heat transfer between the wall and the fluid. The appraisement of the performance evaluation criterion (PEC) illustrates that the wavy case with an amplitude of 250 μm and wavelength of 2500 μm is the best geometry from the thermal-hydraulic point of view in the studied range. Finally, with variable flux condition, the wavy microchannel has responded well to the temperature increase and has created a much more uniform surface temperature compared to straight pattern. The proposed wavy pattern ensures that there are no hotspots which could damage the electronic chip. Presented wavy patterns can be used in heat sinks heat transfer enhancement to allow the chip to run in higher heat fluxes.
进行了一项数值研究，以研究波浪形微通道抑制电子设备中产生的温度波动的能力。考虑了五种波浪形图案，其振幅和波长范围分别为62.5至250μm和1250至5000μm，以研究波浪形图案内流动的控制现象对热工水力性能的影响。流动状态为层流，雷诺数在300至900范围内，并且向微通道基板施加了80W/cm的相对较高热通量。此外，还研究了80、120、160、200和240W/cm热通量以及最有效的波浪形和直微通道的可变通量条件。结果表明，振幅与波长比更大的几何形状具有更小的曲率半径和更大的Dean数，并且由于横向流（二次流）放大，它们具有增强的传热效果。此外，通过比较横向速度分量与轴向分量的比值，发现通过减小曲率半径和增加Dean数，横向速度增加，这增强了壁与流体之间的传热。性能评估标准（PEC）的评估表明，在所研究范围内，从热工水力角度来看，振幅为250μm、波长为2500μm的波浪形情况是最佳几何形状。最后，在可变通量条件下，波浪形微通道对温度升高响应良好，并且与直通道相比，产生了更加均匀的表面温度。所提出的波浪形图案确保不存在可能损坏电子芯片的热点。所呈现的波浪形图案可用于增强散热器的传热，以使芯片在更高的热通量下运行。
