锯齿形振动风扇对热壁面对流换热效果的影响

Effect of Serrated Vibrating Fans on Convective Heat Transfer at Heated Wall Surfaces

建立电磁振动风扇热壁面散热模型,研究电磁振动风扇对恒热流壁面的对流换热效果。以矩形扇叶为基础,构造9种锯齿形扇叶,采用实验和数值模拟研究方法,研究不同扇叶的散热效果。结果表明,在研究范围内,锯齿数最多时的三边锯齿扇叶对恒热流壁面的散热效果最佳,与矩形扇叶相比,该锯齿型扇叶使壁面平均温度和最高温度分别下降3.3℃和5.2℃。数值模拟结果与实验结果吻合较好。流场分析结果表明,在锯齿的作用下,扇叶诱导产生的大尺度旋涡被打碎成小尺度旋涡,因此对流传热得到增强。

A heat dissipation model using the electromagnetic vibration fan on a heated wall was setup to study the convective heat transfer performance of the heated wall.Based on the rectan-gular fan blade,nine types of serrated fan blades were constructed.The experiment and numerical simulation were used to study the heat dissipation effects of the blades.The results showed that the three-sided serrated blade with the highest number of serrations has the best heat dissipation performance in the present range.The average and maximum wall temperatures were decreased by 3.3℃ and 5.2℃,respectively,in comparison with the rectangular blade.The numerical simulation results are in good agreement with the experimental results.The flow field analysis showed that the large scale vortex is broken by the saw tooth,and hence the convective heat transfer is enhanced.