齿形叶片降低离心式风机噪声的实验研究

Experimental Study on Noise Control of a Centrifugal Blower Using Tooth Shape Vane

对离心式风机的齿形叶片降噪机理进行了研究 ,结果表明 :齿形叶片的降噪效果与叶道内气流的涡流状态有关 ,雷诺数 Re在 4× 1 0 5 ～ 6× 1 0 5 范围内的降噪效果较为明显 ,降噪量达到 4～ 5d B,其他范围降噪作用不明显。齿节距 t=b/ 5、齿高 h=b/ 1 0的降噪量为 2 .5d B,下降 2 .3 %左右 ,平均全压基本不变 ,平均效率仅下降1 .5%。

The mechanism of noise decreasing of a centrifugal blower by tooth shape vane was studied in this text. The experiments showed that the effect of tooth shape vane on noise decreasing was related to the vortex state of airflow in vane passage. For Reynolds number Re=4×105 [similar to] 6×105, a better effect of noise decreasing was obtained corresponding to the noise decreasing 4 [similar to] 5 dB. Beyond the above values of Reynolds number, the tooth shape Vane didn't act on noise decreasing at all. At tooth distance t=b/5 and tooth altitude h=b/10 the level of noise reached 2.5 dB decreased by 2.3%. However, its average kept constant and the average efficiency decreased by only 1.5%.