对大功率LED太阳花散热器肋片三角槽扩展表面的散热性能进行了数值模拟与分析,并对肋片长度方向的温度分布进行了实验验证。在考虑自然对流和辐射模型的条件下,研究了肋片表面三角槽的顶角α、槽宽s和槽深d对散热器肋片顶部最高温升ΔT_max、平均对流换热系数h和对流换热热阻R的影响。结果表明:顶角α在90°~120°范围内、向肋片根部倾斜的三角槽在增加散热面积的同时,改善了流场分布,从而显著地增强了太阳花散热器的散热性能;相比于槽宽s,槽深d对平均对流换热系数h影响更为显著,较小或较大的槽深会因平均对流换热系数h的大幅降低而恶化散热效果。

The heat transfer performances of a sunflower radiator with triangular groove extended surfaces for high-power LEDs are numerically simulated and analyzed. The temperature distribution in the direction of fin length is experimentally tested. Under the condition that the natural convection and radiation model is considered, the effects of apex angle α, groove width s and groove depth d on the maximum temperature rise ΔTmax at the top of fins, average convective heat transfer coefficient h and convective thermal resistance R are investigated. The results show that the existence of triangular grooves with apex angles of 90°-120° and inclining to fin root increases the heat dissipation area and also improves the fluid-flow distribution, and thus the heat transfer performances of sunflower radiator are significantly enhanced. Compared with that of groove width s, the influence of groove depth d on the average convective heat transfer coefficient h is more remarkable. A small or large groove depth deteriorates the heat transfer performance due to the significantly decreased average convective heat transfer coefficient h.