转速变化对离心泵性能影响的数值模拟

以1200S56型双吸离心泵为研究对象,通过Fluent软件,运用雷诺时均方程和RNGk-ε湍流模型,结合SIMPLEC算法,对其8个转速下的5组相似工况进行三维全流道数值模拟.由模拟结果分析相似工况点上泵内部流场的变化情况,发现在相似工况下泵内部流场高度相似,符合泵的相似理论.由数值模拟结果计算各工况的性能参数,得出数值模拟预测值相对于比例定律计算值的误差.结果显示,转速变化时,泵的效率下降很小,而扬程、功率的相对误差多数都在1％以内,说明比例定律能较好地反映泵的性能参数随转速的变化情况.

Numerical simulation of influence of rotational speed change on performance of centrifugal pump

A 1200S56 double-suction centrifugal pump was chosen as the research object and the Reynolds time-average equation,standard k-ε turbulence mode and the SIMPLEC algorithm were used to simulate its three-dimensional full-flow passage of its 5 similar working point groups under 8 rotational speeds.According to the simulation results,the change of internal flow field with similar working points of the pump was analyzed.It was found that the internal flow patterns are highly similar in similar working points and the result was consistent with the similarity theory of pump.Meanwhile,performance parameters in different working points were calculated by using simulation result.Then the error of numerical simulation result from that of scaling law was also calculated.The result showed that the efficiency of the pump decreased by a very small quantity and most of relative errors of its head and power were within 1% as the rotational speed changing,meaning that the scaling law could reflect the change of performance parameters as the rotational speed changing.