摘要
设计开发了一种新型轴向导叶,基于CFD方法进行了全流场三维定常和非定常数值模拟,探讨了该新型轴向导叶内部的压力脉动现象,得到了额定工况下首级叶轮出口、次级叶轮出口、首级导叶内部和次级导叶内部压力脉动特性,并通过快速傅里叶变换进行了频域分析.结果表明:与空间导叶相比,轴向导叶水力性能略低,但较径向导叶有很大优势;新型轴向导叶的压力脉动产生于叶轮出口与导叶进口交界处,且在向导叶传输的过程中脉动信号呈衰减趋势;从导叶进口至导叶出口,导叶内的压力脉动幅值明显降低,表明该轴向导叶压力转换能力强;次级轴向导叶内压力脉动幅值低于首级导叶;各监测点主频均与叶频相等或为叶频整数倍,首级导叶和次级导叶内频域分布存在一定差别.
A new type axial diffuser is devised and the unsteady,three-dimensional and turbulent flow field in a plastic well pump with this diffuser is simulated based on a CFD method to exploit the internal pressure pulsation phenomenon in the diffuser. The pulsation characteristics of pressure at the first and second stage impeller outlets as well as inside the first and second stage diffuses are obtained under the duty flow rate conditions; meanwhile,the frequency fluctuation of pressure is analyzed by fast Fourier transform. Compared with a bowl diffuser,the hydraulic performance of the axial diffuser is slightly poorer,but much better than a radial diffuser. The maximum pressure pulsation occurs at the interface between the impeller and the axial diffuser,and the magnitude of the pulsation declines when the fluid passes the diffuser. From the inlet to the outlet,the amplitude of pressure pulsation in the axial diffuser is significantly reduced,indicating an excellent pressure recovery capability. In addition,the amplitude of pressure pulsation in the second stage diffuser is lower than that in the first stage. The dominantfrequency at various monitoring points is equal to the blade passing frequency or is an integer multiple of the frequency. There are some differences in the frequency domain distribution from the first stage diffuser to the second stage one.
出处
《排灌机械工程学报》
EI
CSCD
北大核心
2016年第1期18-25,共8页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51309118
51279069)
江苏省自然科学基金资助项目(BK20130527)
现代农业装备与技术教育部重点实验室开放基金资助项目(NZ201305)
关键词
塑料井泵
新型轴向导叶
导叶设计
压力脉动
数值模拟
plastic well pump
new axial guide vane
guide vane design
pressure pulsation
numerical simulation
