The reliability of electronics systems primarily depends on the temperature of the electronics components. The development of cost-effective thermal management solutions to cater to the cooling of next-generation electronics systems is the need of the hour. The extended surface is the most reliable, convenient, and cost-effective heat transfer technology to remove the heat generated by the electronics components. Power amplifiers are the critical devices used for outdoor communications which generate high heat flux during their operation. Since the communication systems are installed outdoors, the average solar irradiation falling on the system during sunny days is 600 W/m 2 . A computational fluid dynamics (CFDs) model of a heatsink with a base area of 100 mm ×100 mm exposed to solar irradiation is developed to dissipate the heat generated by the power amplifier. The fin height is varied from 5 to 30 mm, fin thickness is varied from 2 to 3 mm and the spacing between the fins is varied from 4 to 6 mm. Surface properties such as emissivity and solar absorptivity of the fin surface are varied from 0.1 to 0.9 to study the effect of solar irradiation on the efficiency of the fin. For 30 mm fin height and emissivity 0.1, the heatsink base temperature increases from 57.8 °C to 66.1 °C and the fin efficiency reduces from 97.5% to 94.3% when the solar absorptivity of the fin surface is increased from 0.1 to 0.9. Similarly, for fin height 5 mm and emissivity 0.9, the heatsink base temperature increases from 63.9 °C to 77.7 °C and the computed fin efficiencies are 96.4% and 93.2% for solar absorptivity 0.1 and 0.9, respectively. Experiments are conducted to measure the base temperature of a heatsink to validate the CFD results. The contours of thermal resistance of heatsink for various configurations are plotted and an electronics cooling designer can choose an appropriate heatsink by knowing the geometric and surface properties of the heatsink.

中文翻译：

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太阳辐射对散热器热性能的影响——数值与实验研究


电子系统的可靠性主要取决于电子元件的温度。开发具有成本效益的热管理解决方案来满足下一代电子系统的冷却需求是当前的需要。扩展表面是消除电子元件产生的热量的最可靠、最方便且最具成本效益的传热技术。功率放大器是户外通信的关键设备，在运行过程中会产生高热通量。由于通信系统安装在室外，晴天时系统的平均太阳辐射量为600 W/m 2 。开发了一个暴露在太阳照射下的底部面积为 100 mm × 100 mm 的散热器的计算流体动力学 (CFD) 模型，用于散发功率放大器产生的热量。翅片高度从 5 到 30 mm 变化，翅片厚度从 2 到 3 mm 变化，翅片之间的间距从 4 到 6 mm 变化。翅片表面的发射率和太阳吸收率等表面特性在 0.1 至 0.9 之间变化，以研究太阳辐射对翅片效率的影响。对于 30 mm 翅片高度和发射率 0.1，当翅片表面的太阳能吸收率从 0.1 增加到 0.9 时，散热器底座温度从 57.8 °C 增加到 66.1 °C，翅片效率从 97.5% 降低到 94.3%。同样，对于翅片高度 5 mm 和发射率 0.9，散热器底座温度从 63.9 °C 增加到 77.7 °C，计算得出的翅片效率对于太阳能吸收率 0.1 和 0.9 分别为 96.4% 和 93.2%。进行实验来测量散热器的基础温度，以验证 CFD 结果。 绘制了各种配置的散热器热阻等值线，电子冷却设计人员可以通过了解散热器的几何和表面特性来选择合适的散热器。