竖直热沉自然对流散热的两种强化措施研究

Two Effective Approaches to Enhance Natural Convection of Vertical Heatsink

为了对高效大功率远端射频模块(RRU)的散热器设计提供依据,本文提出了两种强化直翅式竖直热沉自然对流散热的有效措施:对完整热沉在中间位置开缝同时在开缝处添加挡片,以及对开缝热沉存在的局部传热不利区域开孔来强化散热。本文采用了实验手段结合数值模拟的方法,研究了两种逐次递进的改进措施对给定几何结构参数的直翅式竖直热沉散热性能的影响。研究结果表明:当开缝宽度为10 mm时,中间开缝并添加挡片之后,竖直热沉散热性能显著提升;开缝从中间位置分别向上或向下平移时,散热性能均逐渐减弱。添加挡片后的中间开缝热沉肋间流场存在传热死区,通过对该区域内的翅片开孔能够有效减少传热死区的面积;开孔不仅改变了肋间空气的流向,而且形成了漩涡现象和扰流运动,从而进一步强化了热沉整体的散热性能。

In order to provide a basis for the designs of Radio Remote Unit(RRU)with high-performance and large power, two effective approaches were proposed to enhance natural convection of the vertical straight-fin heatsink: slotting the continuous heatsink in the middle with the baffle plate and perforating into local heat zones. Experiments and numerical simulation were used to investigate the effect of two measures on the natural convection of the heatsink. It is shown that the method to slot the heatsink in the middle with the baffle plate, which has an obvious effect on heat transfer enhancement of the vertical heatsink when the width of interruption is 10 millimeters. The heat dissipation performance will be weakened gradually no matter the position of slotting moves up or down. Moreover, an obvious high temperature zone still exists in the discontinuous heatsink with a baffle plate. While the perforating into the local zone can reduce the area of such a high temperature zone. Perforation not only changes the flow direction of air between fins, but also forms a whirlpool and turbulent flow, thus enhancing the overall heat dissipation performance of the heatsink.