Time Resolved PIV Analysis for Low Frequency Noise Generated at Low Flow Rate Mode of Multi-Blade Centrifugal Fan
Time Resolved PIV Analysis for Low Frequency Noise Generated at Low Flow Rate Mode of Multi-Blade Centrifugal Fan
复制标题
多翼离心风机低流量模式下低频噪声的时间分辨PIV分析
DOI：
10.11458/tsj.47.4_208
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
川埼真俊，平原裕行，箭内優樹，姜東赫
中科院分区：
文献类型：
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作者：
白鳥 英;加藤 大輝;島野 健仁郎;永野 秀明;松本裕昭;川埼真俊，平原裕行，箭内優樹，姜東赫
利用时间分辨PIV技术，从低频脉动流场的角度对多翼离心通风机低流量噪声问题进行了实验研究。现有的PIV设备由于将数据采集速率设置为与BPF相当，因此可以在没有叶片通过波动的情况下通过叶片观察来检测低频速度波动。实验结果表明，在涡卷角θ= 120 °时，叶轮出口局部存在较大的流动脉动。这种脉动流在蜗壳内被输送到下游，沿着叶轮出口主流的外侧通过。在涡壳出口附近，这种脉动流分为流向叶轮的反向流和流向舌部的流动。在θ= 120附近，反向流动再次通过叶轮返回蜗壳。因此，确认了由于该循环波动而产生低频噪声。
A noise problem at a low flow rate of multi-blade centrifugal fan was investigated experimentally in terms of low frequency fluctuation in flow by using a time resolved PIV. The present PIV equipment makes blade by blade passing observation be possible to detect the low frequency velocity fluctuation without blade passing fluctuation, because the data acquisition rate was set equivalent to BPF. The experimental results show that the flow at the impeller outlet has a large fluctuation locally, in the present case, at the scroll angle θ= 120. This fluctuated flow was transported to the downstream in the scroll casing, which passed along the outside of the main flow exited from the impeller. This fluctuated flow was divided into a reverse flow to the impeller and a flow towards tongue in the vicinity of the scroll exit. The reverse flow returned again near θ= 120 through the impeller towards the scroll casing. Thus, it was confirmed that the low frequency noise was generated due to this circulating fluctuation.