非均匀叶轮对多翼离心风机气动性能和噪声的影响

Effect of Non-uniform Impeller on the Aerodynamic Performance and Noise of a Multi-blade Centrifugal Fan

为探索叶片非均匀布置对多翼离心风机性能和噪声的影响,本文采用叶片沿叶轮周向正弦分布和随机分布两种方式设计五种叶片非均匀分布方案。基于非均匀叶片对风机通过频率的调节,通过数值模拟和气动性能试验的对比分析,得出了非均匀调制程度和方式对风机气动性能的影响规律,并对不同方案进行了噪声性能试验。结果表明:当叶片非均匀程度相对变化值小于20%时,叶片分布方案对风机气动性能影响较小;对于正弦调制,当调制周期是2,调制幅度为0.04时,风机气动性能与原模型最接近,其它方案性能略有下降。叶片非均匀方案对应风机噪声下降2～4dB,其中正弦调制方案调制周期是2,调制幅度为0.08时降噪效果最明显,噪声最大下降4dB。

In order to explore the effect of non-uniform blade placement on the performance and noise of multi-blade centrifugal fans,five kinds of non-uniform distribution schemes are designed by the blade along the impeller circumferential sinusoidal distribution and random distribution.Based on the adjustment of the fan passing frequency through the nonuniform blade,and the comparison between the numerical simulation and the aerodynamic performance test,the influence of the non-uniform modulation degree and mode on the aerodynamic performance of the fan was obtained,the noise performance of different schemes were tested.The results show that the blade distribution has less effect on the aerodynamic performance when the relative variation of the blade is less than20%.For the sinusoidal modulation,when the modulation period is2and the modulation amplitude is0.04,the aerodynamic performance of the fan is closest to that of the original model,while the performance of other schemes is slightly reduced.In the non-uniform scheme of blades,the corresponding fan noise is reduced by2~4dB,in which the modulation period of the sinusoidal modulation scheme is2and the amplitude is0.08,the noise reduction effect is the most obvious,and the maximum noise is reduced by4dB.