In this work, pin fin and plate heat sinks were investigated in terms of natural convection and radiation heat transfer by experimental means. One rectangular base plate and eight pin fin and plate heat sinks were manufactured particularly for this study. Eight different pin fin and plate heat sinks had four different pin fin numbers and hence pin fin spacings; and two different pin fin heights. Three different orientations of 0°, 90° and 180° were tested. Ten different constant heating rates were applied to heat sinks during tests, corresponding to Rayleigh number interval between 1 × 10⁶ and 7 × 10⁶. Heating powers were changed between 5 and 50 W by 5 W increments by means of DC electrical power source. All cases were compared with each other. Results were evaluated by calculating heat transfer indicators from experimental measurements, dependent Nusselt and Rayleigh numbers, and by drawing their corresponding graphics. It was detected that increasing pin fin number up to a threshold value increases thermal performance. After the threshold pin fin number, thermal convection coefficient decreases significantly. Up to the favourable highest pin fin number, the reason of thermal performance enhancement is due to increasing surface area without deteriorating thermal convection coefficient significantly. It is also seen that extended surface area by increasing number of pin fins partly compensates the reduction in thermal convection coefficient up to a level. However, increasing pin fin number further degrades heat transfer performance. Results show that the highest heat transfer is achieved by 121 × 40 pin fin and plate heat sink for all three orientation angles. The lowest heat transfer performance is realized by non-pinned plate. When plate orientation is considered, the highest heat transfer is achieved with upward facing orientation which has 0° orientation angle value, and the lowest heat transfer rate is realized with downward facing heat sink which has 180° orientation angle value. Therefore, it is concluded that inline pin fin and plate heat sinks are best used with upward orientation with optimum number of pins. Experimental dataset was analysed in terms of parametrical effects and accordingly empirical correlations expressions were composed and proposed.

在这项工作中，通过实验手段从自然对流和辐射传热方面研究了针翅片和板式散热器。为这项研究专门制造了一个矩形底板和八个针式翅片和板式散热器。八个不同的针式散热片和板式散热器具有四种不同的针式散热片数量以及针式散热片间距；和两个不同的针鳍高度。测试了 0°、90° 和 180° 三种不同的方向。在测试过程中对散热器施加了十种不同的恒定加热速率，对应于 1 × 10 ⁶和 7 × 10 ⁶之间的瑞利数区间. 加热功率通过直流电源在 5 和 50 W 之间以 5 W 的增量变化。所有案例都进行了相互比较。通过从实验测量、依赖的 Nusselt 和 Rayleigh 数计算传热指标并绘制相应的图形来评估结果。检测到将针鳍数量增加到阈值会提高热性能。在阈值pin fin数之后，热对流系数显着降低。在有利的最高针翅数之前，热性能增强的原因是由于增加了表面积而没有显着降低热对流系数。还可以看出，通过增加针状翅片的数量而扩大的表面积部分补偿了热对流系数的降低，达到一定水平。然而，增加针翅数量会进一步降低传热性能。结果表明，对于所有三个方向角，121 × 40 针翅片和板式散热器实现了最高的热传递。非销钉板实现了最低的传热性能。当考虑板片取向时，0°取向角值的朝上取向实现了最高的传热，而取向角值为180°的朝下散热片实现了最低的传热率。因此，得出的结论是，内嵌针式散热片和板式散热器最好以向上的方向使用，并具有最佳的针数。