基于流声耦合法的超低比转数离心泵空化特性研究  

Cavitation Characteristics of Ultra-low Specific Speed Centrifugal Pump Based on Fluid-Acoustic Coupling Method

作　　者：王勇[1] 赵宇琪[1] 董亮[1] 代翠[2] 刘厚林[1] 徐海良 

机构地区：[1]江苏大学流体机械工程技术研究中心,镇江212013 [2]江苏大学能源与动力工程学院,镇江212013 [3]君禾泵业股份有限公司,宁波315171

出　　处：《农业机械学报》2017年第12期114-123,共10页Transactions of the Chinese Society for Agricultural Machinery

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)

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。Centrifugal pumps are widely used in various fields. The cavitation not only causes the destruction of over-current components so as to influence the reliability of operation,but also affects the pump running stability because of vibration noise. In many cases,cavitation is unavoidable. Therefore,it is necessary to improve the accuracy of cavitation monitoring and reduce the unnecessary loss caused by cavitation. The objective was to study the variation law of noise characteristics under different cavitation conditions of centrifugal pump,and the influence of cavitation development on hydrodynamic noise. The previous scholars used the test methods to get the noise signals,but the signals were not the same as different product characteristics of pumps. Therefore,it is a cost-effective method to predict the cavitation noise by numerical simulation. And the experimental method was used to verify the accuracy of numerical calculation. Firstly,an ultra-low specific speed centrifugal pump was used as the research object to build a closed test bench. Based on the pump product test system and data acquisition system,a test system of centrifugal pump cavitation noise and performance was established to realize pump performance parameters and internal field noise signals synchronization acquisition. The cavitation performance curves of the model pump were predicted by Kunz cavitation model and Zwart cavitation model respectively. And the experimental values were compared with to select the appropriate cavitation model. According to thevapor volume fraction distribution among blades and cavitation performance curve,the whole cavitation process was divided into non-cavitation stage,nascent cavitation stage,feature cavitation stage and serious cavitation stage. The effects of cavitation on internal flow field and pressure at different times during pump operation were analyzed. The acoustic boundary element method was used to transform the flow field information into sound field information. The relative error of the noise pred

关 键 词：超低比转数离心泵 空化 噪声 流声耦合法 试验 

分 类 号：TK72[动力工程及工程热物理—流体机械及工程]