采用仿鱼形叶片的多翼离心风机性能研究
Study on the Aerodynamic Performance of Multi？？Blade Centrifugal Fan with Bionic Blades Inspired by Carangiform Fish

受？科鱼类机动游动姿态和涡流特征启发,设计了一种仿？科鱼体弯曲姿态的多翼离心风机用仿生叶片,采用数值模拟方法,分别研究了常规单圆弧原型叶片和仿鱼形叶片对多翼离心风机气动性能、噪声的影响。通过可视化分析发现,在仿鱼形叶片的叶道内,旋涡强度明显小于原型风机,流场分布更加均匀。仿鱼形叶片的采用有效降低了风机蜗舌处的压力脉动,减弱了叶片与蜗舌之间的非定常相互作用。风机气动噪声计算与分析结果表明,单圆弧原型叶片的风机噪声频率分布于低频声段和中频声段,而仿鱼形叶片的风机噪声频率主要集中在中频声段范围内,这表明两种风机的噪声频率分布规律和噪声传播路径不相同。数值计算结果表明,采用仿鱼形叶片的多翼离心风机气动性能明显得到改善,其中风量增加了12.5％,效率提升了5.65％,同时测点处噪声平均值下降了2.78 dB。
Inspired by the maneuvering swimming posture and vortex characteristics of carangiform fish, a bionic blade of the multi？？blade centrifugal fan is designed according to the turning feature of carangiform fish. Numerical method is conducted to investigate the effects of bionic blade and single？？arc blade on the aerodynamic performance of multi？？blade centrifugal fan. Compared with the original centrifugal fan with the single？？arc blades, the flow rate and efficiency of the multi？？blade centrifugal fan with the bionic blades are increased by 12？？5％ and 5？？65％, respectively. The vortex intensity in the impeller channel consisting of bionic blades is weaker than that in the original impeller channel with single？？arc blades. The pressure fluctuation occurring near the region of volute tongue is suppressed and the periodic unsteady interaction between the impeller and the volute tongue is weakened. When the bionic blade is used, the aerodynamic performance of multi？？blade centrifugal fan is improved. Numerical results on the aerodynamic noise show that for the original fan, low？？frequency and intermediate？？frequency noises have important contributions to the sound pressure level while the aerodynamic noise of the centrifugal fan with the bionic blades mainly concentrates in the intermediate？？frequency sound section. The distribution of noise frequency and noise propagation path of the original fan are different from that of the multi？？blade centrifugal fan with the bionic blades. Compared with the original fan, the average A？？weighted sound pressure level of the centrifugal fan with the bionic blades is reduced by 2.78 dB