离心泵仿生叶片的降噪特性研究

Study on Noise Reduction Characteristics of Bionic Vane of Ventrifugal Pump

采用仿生学思维对离心泵叶片出口进行仿生改造,结合CFD和噪声计算对设计工况下的流场和声场信息进行对比分析,用数值模拟方法验证其结构改进后的降噪效果。计算结果表明:采用仿生结构叶片能够有效的降低隔舌、蜗壳出口和叶轮流道内的湍流脉动强度,同时使流场中的涡结构尺度减小,控制流场中涡结构的分布范围,降低了离心泵内噪声源强度,达到降低噪声的目的。原模型和仿生叶片模型的压力脉动特征频率均为叶频及其低阶倍频,仿生叶片模型在各监测位置的压力脉动均比原模型有明显的降低;仿生叶片使各监测点噪声源强度降低,其出口3倍管径处的降噪效果最佳,总声压级下降3.62 dB,降噪率为3.20%;在隔舌处的总声压级下降1.15 dB,降噪率为0.67%,总体降噪率在0.67%~3.20%,达到了降噪的目的。

Based on the bionic thinking,the bionic transformation of the centrifugal pump blade outlet was simulated,combined with CFD and noise calculation,the flow field and acoustic field information under the design condition were compared and analyzed,and the noise reduction effect after structure modification was verifiedby using numerical simulation method.The calculation results show that the bionic blades can effectively reduce the turbulence pulsation intensity in the flow channel of the sublingual,volute outlet and impeller,reduce the vortex structure scale in the flow field,and control the distribution of the vortex structure in the flow field,which reduces the noise source strength in the centrifugal pump and realizes the purpose of noise reduction.The pressure pulse characteristic frequencies of the prototype and bionic blade model are both the frequency of the blade and its low order frequencies,and the pressure pulsation of the bionic blade model in each monitoring position is significantly lower than the original model;the noise source intensity is decreased at each monitoring points by the bionic blade,the noise reduction effect in outlet triple tube is the best,the total sound pressure level decreases by 3.62 dB with the noise reduction rate of 3.20%;the total sound pressure level of the sublingual decreases by 115 dB with the noise reduction rate of 0.67%,and the overall noise reduction rate is in the range of 067%to 3.20%,achieving the purpose of noise reduction.