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为研究离散格式对离心泵性能预测精度的影响,本文以自吸式离心泵为计算模型,采用Realizableκ-ε湍流模式进行三维内流场的数值模拟研究,分析了从零流量到最大工作流量下的内部流动和水力性能。建立了考虑内部间隙影响的自吸式离心泵全三维计算模型,分析了动量方程对流项采用一阶差分和二阶差分格式对计算精度的影响,同时分析了压力项的Standard和PRESTO离散格式对计算精度的影响。结果表明,在小流量工况下,采用二阶迎风格式具有较高的计算精度,而在大流量工况下采用一阶迎风格式更为合适。该结果可为准确预测离心泵全工况外特性提供参考依据。
In order to study the influence of discrete format on centrifugal pump performance prediction accuracy, this paper uses self-priming centrifugal pump as a model to study the numerical simulation of three-dimensional internal flow field with Realizable κ-turbulence model. From zero flow to maximum working flow, Internal flow and hydraulic performance. The full three-dimensional calculation model of self-priming centrifugal pump considering the influence of internal clearance was established. The influence of first-order difference and second-order difference schemes on the accuracy of convection term of momentum equation was analyzed. The Standard and PRESTO discrete-time pressure format Effect of calculation accuracy. The results show that the second-order upwind scheme has a higher accuracy at low flow rates and the first-order upwind scheme at high flow rates is more suitable. The results provide a reference for accurately predicting the out-of-service characteristics of centrifugal pumps.