半螺旋形吸水室对离心泵压力脉动特性的影响

以某型号双吸泵为研究对象，分析了半螺旋形吸水室几何参数对离心泵内部不稳定流场压力脉动的影响。在保证吸水室基本几何参数不变的情况下，通过改变吸水室断面形状与隔舌位置而设计了2种计算方案。基于Navier-Stokes方程和标准的 双方程紊流模型，采用贴体坐标、非结构化四面体网格和SIMPLEC算法，分别对不同设计方案的双吸离心泵进行全流道非稳态数值计算，得到各设计方案下离心泵监测点的压力脉动特性，并对其分析。计算结果表明：方案Ⅱ随着吸水室断面形状的改变，以及隔舌位置由与水平线成90o变为45o，吸水室内监测点的压力变化时域曲线趋于均匀、平缓；在压水室中，由于隔舌处监测点主要受隔舌与叶轮的动静干涉的影响，两种方案的压力脉动情况几乎一致，而其他监测点的压力变化均匀性方案Ⅱ明显优于方案Ⅰ，从而提高了机组运行的稳定性，为进一步研究双吸离心泵吸水室的设计提供了理论和实际应用参考。

Effect of half-spiral suction chamber on pressure fluctuation

Regarding a type of double suction pump as the research object, analyses the effect of the geometry parameter of half-spiral suction chamber on the unstable flow field’s pressure pulsation in a centrifugal pump. On the basis of ensuring the same that the basic geometric parameters of suction chamber, designed two kinds of calculation scheme by changing the shape of cross section and the position of tongue. The full port unsteady numerical calculation were performed for the double suction centrifugal pump of different design scheme,based on the Navier-Stokes equation and the standard two-equation turbulent model of ,using the body-fitted coordinates,unstructured-tetrahedron grid and SIMPLEC algorithm,which obtained the pressure pulsation characteristics of the monitoring points in centrifugal pump and analysed. The calculation results indicates, with the change of the suction chamber section shape and tongue location with horizontal line from 90o to 45o, the curves of pressure changes that the suction chamber monitoring points in scheme Ⅱ tend to be uniform and smooth; in the pressurized-water chamber, affected mainly by the rotor-stator interaction of impeller and tongue,the pressure fluctuation of two schemes are the same almost in the tongue, while the uniformity of the monitoring points’ pressure change of the scheme Ⅱis better than the scheme Ⅰ,which improved the stability of unit operation, and provides a theoretical reference and practical application for further studying the design of the double suction centrifugal pump suction chamber .