Purpose

This study aims to propose the increase of heat dissipation requirements of modern electronic equipment and the fast development of micro-scale manufacturing technologies. The heat transfer mechanism is studied in-depth, especially for its pattern of secondary flow caused by the repeated inversion of centrifugal force. Effects of η on the frictional pressure drop and average Nusselt number are studied and the performance of such microchannel heat sink with various bend amplitudes is comprehensively evaluated. These results can provide important insight into the optimal design of this novel design configuration for microelectronics cooling.

Design/methodology/approach

A three-dimensional model based on the finite volume approach and SIMPLEC algorithm is performed to test an innovative serpentine microchannel, which behaves differently from conventional serpentine microchannel due to the significant effect of centrifugal force inversion.

Findings

The effect of centrifugal force significantly influences the flow and thermal fields which are responsible for the enhancement in heat transfer coefficient. The number, size and intensity of vortices increase with increasing Re, and the vortices are reformed at every change of the geometry in a periodic fashion. The serpentine microchannel studies more effectively at larger bend amplitude. Pressure fluctuations and temperature variation are greater with increasing bend amplitude.

Practical implications

Several techniques have been developed to augment single-phase convective heat transfer in channels. One technique is to use a serpentine channel that enhances the heat transfer due to flow mixing and periodic interruption of thermal boundary layers. This technique has been applied to micro-heat exchangers, thermal regenerators and mini/microreactors.

Social implications

The optimal design of this novel design configuration for microelectronics cooling can be attained. It will become an effective cooling technology for solving the increasing of heat dissipation requirements of modern electronic equipment.

Originality/value

The flow and heat transfer characteristics are first presented for the circular serpentine microchannel made up of alternate U-bends without interposed straight segments. The present study first examines the effect of such centrifugal force inversion on velocity contour, pressure distribution and temperature distribution. The patterns of secondary flow along the flow passage caused by the repeated inversion of centrifugal force are further studied in depth. The effect of bend amplitude on the flow and heat transfer is explored and the performance of such microchannel heat sink has been comprehensively evaluated.

中文翻译：

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弯曲幅度可变的蛇形微通道内流动和传热特性的数值分析

目的

这项研究的目的是提出增加现代电子设备的散热要求以及微型制造技术的快速发展。对传热机理进行了深入的研究，特别是对因离心力的反复反转而引起的二次流动模式进行了深入研究。研究了η对摩擦压降和平均Nusselt数的影响，并综合评估了这种具有不同弯曲幅度的微通道散热器的性能。这些结果可以为微电子冷却的新颖设计配置的最佳设计提供重要的见识。

设计/方法/方法

进行了基于有限体积方法和SIMPLEC算法的三维模型来测试创新的蛇形微通道，由于离心力反转的显着影响，该蛇形微通道的行为不同于常规的蛇形微通道。

发现

离心力的作用会显着影响流场和热场，这会增加传热系数。涡旋的数量，大小和强度随Re的增加而增加，并且涡旋在几何形状的每次变化时都以周期性的方式重新形成。蛇形微通道在更大的弯曲幅度下更有效地研究。随着弯曲幅度的增加，压力波动和温度变化会更大。

实际影响

已经开发了几种技术来增强通道中的单相对流换热。一种技术是使用蛇形通道，该通道由于流动混合和热边界层的周期性中断而增强了热传递。该技术已应用于微型热交换器，热再生器和微型/微型反应器。

社会影响

可以实现这种新颖的微电子冷却设计配置的最佳设计。它将成为解决现代电子设备散热要求不断提高的有效冷却技术。

创意/价值

首先介绍了圆形蛇形微通道的流动和传热特性，该蛇形微通道由交替的U形弯头组成，没有插入直的段。本研究首先研究了这种离心力反演对速度轮廓，压力分布和温度分布的影响。深入研究了由离心力的反复反转引起的沿流道的二次流的模式。探索了弯曲幅度对流动和传热的影响，并已全面评估了这种微通道散热器的性能。