中文摘要：

为研究双蜗壳式离心泵内部流动特性,基于标准k-ε湍流模型和标准无滑移网格模型,应用CFX软件对其不同工况下的非定常流动进行三维数值模拟,得到了不同工况下双蜗壳式离心泵叶轮和蜗壳内部流道的压力脉动特性。计算结果表明,在小流量工况下,各监测点处的压力脉动都比较大且不均匀;在叶轮流道中,叶轮流道靠近出口边缘的压力脉动是叶轮流道其他区域压力脉动的5～8倍;在流量Q为34、110、148、160 m^3/h 4个工况下叶轮分别旋转30步（90°）和90步（270°）时,压力脉动出现最大值。双蜗壳内圈流道的压力脉动强于外圈流道的压力脉动且隔舌处出现压力脉动较大值,大流量工况下双蜗壳隔舌和出口产生一定回流导致蜗壳该处附近监测点压力脉动先减小后增大。从傅里叶变换得到频域特性可知,叶频及其倍频是压力脉动的主要频率,且呈衰减趋势。

英文摘要：

In order to analyze the internal flow characteristics of a double volute centrifugal pump, the CFD software CFX was applied to simulate the unsteady flow among different working conditions based on standard k -εturbulence model and standard no slip mesh model. The pressure fluctuation characteristics under different working conditions on flow channels both in the impeller and the volute were obtained. The results showed that pressure pulsation of each monitoring point was relatively large and uniform under the condition of low flow rate. Pressure fluctuation near the edge of impeller outlet was 5 - 8 times stronger than that in other region of the impeller. In the case of rotating 30 steps （90°） and 90 steps （270°） during four working conditions, the value of pressure reached to maximum. Pressure fluctuation in the inner flow passage was stronger than that in the outer flow passage of the double volute, and it reached to maximum in the tongue of the double volute. The pressure fluctuation decreased firstly and then increased near the tongue and outlet of volute in the large flow rate due to a certain back-flow. It can be concluded from fast Fourier transform that the frequency of the impeller and its multiples were main frequencies of pressure fluctuation which presented a decreasing tendency.