1673-159X

CN 51-1686/N

叶片圆形切割对离心泵流动诱导噪声的影响

Study on the Influence of Blade Circular Cutting on the Flow-induced Noise of Centrifugal Pump

  • 摘要: 为研究叶片出口圆形切割对离心泵压力脉动及内场噪声的影响,通过固定圆形弦长以变换弦高的方法设计6种叶片切割方案,采用RNG k-ε 湍流模型对各方案外特性和压力脉动进行流场数值计算,并基于Lighthill声类比理论和边界元法(BEM)对内声场进行数值计算,对原始模型额定工况的外特性和内声场也进行了试验验证。结果表明:叶轮叶片切割后的设计方案与原始方案相比,在轴频、叶频及倍叶频处压力脉动得到了明显地改善;当弦高与叶片出口宽度的比值为0.333时,设计工况的压力脉动幅值达到最低; 当弦高与叶片出口宽度的比值为0.167时,进口声压级降低了3.5 dB,出口声压级降低了3.4 dB; 随着圆形切割面积的不断增大,在设计工况各方案声压级呈现出先减小后增大再减小的规律;随着叶片出口圆形切割面积的增大,在0.6 Qv~1.4 Qv工况范围内扬程下降与其呈正相关特性,但对离心泵效率的影响较小。

     

    Abstract: In order to study the influence of blade exit circular cutting on pressure fluctuation and flow-induced noise of centrifugal pump, six kinds of blade cutting schemes were designed by changing chord height by fixed circle chord length. RNG k-ε turbulence model was used to calculate the whole flow field of external characteristics and pressure pulsations of each design scheme. Based on Lighthill sound analogy theory and BEM, the internal acoustic field was calculated. The results show that the design scheme of impeller blade after cutting are compared with the original scheme, the pressure fluctuation at axial frequency, and blade frequency and double blade frequency are improved obviously. When the ratio of chord height to blade outlet width is 0.333, the pressure fluctuation amplitude of the design condition reaches the lowest. When the ratio of chord height to blade outlet width is 0.167, the inlet sound pressure level decreases by 3.5 dB and the exit sound pressure level decreases by 3.4 dB. With the continuous increase of the circular cutting area, the sound pressure level of each scheme shows the characteristics of decreasing first and then increasing and then decreasing. With the increase of the circular cutting area at the blade exit, the head drop in the working range of 0.6 Qv~1.4 Qv has positive correlation with the increase of the circular cutting area, but the effect on the efficiency of the centrifugal pump is less.

     

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