基于流声耦合法的超低比转数离心泵空化特性研究

发布时间：2018-06-16 23:58

本文选题：超低比转数离心泵 + 空化　；参考：《农业机械学报》2017年12期

【摘要】：为研究离心泵不同空化状态下噪声特性的变化规律,以及空化的发展对水动力噪声的影响,首先以一台超低比转数离心泵为研究对象,搭建闭式试验台,基于泵产品测试系统及数据采集系统建立了离心泵空化噪声的试验测试系统,实现了泵性能参数和内场噪声信号的同步采集。其次,分别应用不同空化模型对模型泵空化性能曲线进行预测,并与试验值进行对比,选择合适的空化模型。在此基础上将整个空化过程划分为未空化阶段、空化初生阶段、特征空化阶段及严重空化阶段,结合声学边界元法将流场信息转化为声场信息,并通过比较各空化阶段噪声预测值与试验值相对误差,发现模拟信号与实际信号吻合度较高,充分验证了预测方法的可行性。最后,基于流声耦合法研究空化对内部声场的影响。研究发现:针对超低比转数离心泵空化,Zwart模型比Kunz模型具有更好的适用性。内场噪声信号随空化的发展变化规律比较复杂。在中低频段,由于空化对动静干涉的抑制作用,使得叶频及其倍频特征值离散分量声压级随空化的发展呈现逐渐下降趋势,而轴频分量呈现增大趋势;而高频宽频噪声随空化系数的降低呈现先缓慢减小、然后急剧上升的规律,逐渐将高频特征值分量淹没在宽频带中,高频段声压级的增高造成总声压级的升高。
[Abstract]:In order to study the variation of noise characteristics in different cavitation states of centrifugal pump and the influence of cavitation development on hydrodynamic noise, a closed test bed was built with an ultra-low specific rotation centrifugal pump as the research object. Based on the pump product test system and data acquisition system, a centrifugal pump cavitation noise test system is established, which realizes the synchronous acquisition of pump performance parameters and internal field noise signals. Secondly, different cavitation models are used to predict the cavitation performance curve of the model pump, and the results are compared with the experimental data, and the suitable cavitation model is selected. On this basis, the whole cavitation process is divided into three stages: non-cavitation stage, primary cavitation stage, characteristic cavitation stage and severe cavitation stage, and the acoustic boundary element method is used to transform the flow field information into sound field information. By comparing the relative error between the noise prediction value and the experimental value in each cavitation stage, it is found that the analog signal is in good agreement with the actual signal, which fully verifies the feasibility of the prediction method. Finally, the effect of cavitation on the internal sound field is studied based on the fluid-acoustic coupling method. It is found that the Zwart model is more suitable than the Kunz model for ultralow specific rotation centrifugal pump cavitation. The variation of noise signal with cavitation is complicated. In the middle and low frequency band, because of the influence of cavitation on the static and static interference, the sound pressure level of the discrete component of the blade frequency and its frequency-doubling eigenvalue decreases gradually with the development of cavitation, while the axial frequency component presents an increasing trend. However, with the decrease of cavitation coefficient, the high frequency wideband noise decreases slowly and then rises sharply. The high frequency eigenvalue component is gradually submerged in the wide band, and the increase of the sound pressure level in the high frequency band results in the increase of the total sound pressure level.
【作者单位】：江苏大学流体机械工程技术研究中心;江苏大学能源与动力工程学院;君禾泵业股份有限公司;
【基金】：国家自然科学基金项目(51509111、51779106) 江苏省产学研合作前瞻性联合研究项目(BY2016072-01) 过程装备与控制工程高校重点试验室开放基金项目(GK201403) 中国博士后科学基金项目(2015M581734、2017M611721)
【分类号】：TH311

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