作　　者： (季磊磊）; (李伟）; (施卫东）; (邵佩佩）; (蒋小平）;

机构地区： 江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013

出　　处： 《排灌机械工程学报》 2017年第8期666-673,699,共9页

摘　　要： 为了研究不同叶轮叶片数对混流泵内部流场压力脉动的影响,基于大涡模拟(LES)对混流泵内流场进行非定常数值分析,对比了2种叶片数下混流泵的外特性、叶轮进出口轴向速度分布以及混流泵内各监测点处压力脉动的时域和频域响应.研究结果表明:叶片数对混流泵叶轮进出口的轴向速度影响较明显,随着流量的增加,4叶片叶轮的进口轴向速度和3叶片叶轮的差值逐渐减小,并且3叶片叶轮在叶轮进口具有更高的轴向速度;2种叶片数下各位置处的压力脉动时域图曲线均表现出明显的周期性变化,脉动幅值曲线稳定性较好,导叶出口压力脉动幅值Cp趋于0,但4叶片叶轮在轮毂处的压力脉动呈无周期性变化;2种叶轮进出口附近的主频均为叶频,3叶片叶轮压力脉动频域幅值较4叶片叶轮大,并且在叶轮进出口位置压力脉动频域幅值较高,分频成分较少.研究成果对混流泵的设计优化和揭示不同叶片数混流泵的非定常内部流动特性具有参考意义. In order to study the internal flow field pressure distributions of mixed-flow pump with different numbers of impeller blades over time,the unsteady numerical analysis on mixed-flow pump based on LES model is carried out,and hydraulic characteristic between two kinds of blade number in mixed-flow pump,inlet and outlet of axial velocity distribution of impeller,time domain and frequency domain response of the pressure pulsation at different monitoring points in the mixed-flow pump are all compared.The results show that the inlet and outlet axial velocities are greatly influenced by the number of blades.With the increase of flow rate,the different value of inlet axial velocity between four blade impellers and three blade impellers decreases gradually,and the latter has higher axial velocity in impeller inlet;apparent periodic variation in time domain graph as well as steady pulse amplitude curves are shown intwo kinds of impeller. Cp,the outlet pressure pulsation amplitude of guide blade,tends to 0 while the pressure pulsation in the hub of four blade impeller is aperiodic. The main frequencies near the impeller in mixed-flow pump under three or four blades are both blade frequency. The pressure pulsation frequency domain amplitude is greater in three vane impeller than that in four vane impeller. The results are of significant reference for design optimization and revealing the unsteady internal flow characteristics with different blade numbers of mixed-flow pump.

关 键 词： 混流泵 压力脉动 轴向速度 时域 频域