Numerical Analysis of the Fluid Flow in the First Stage of a Two-Stage Centrifugal Pump With a Vaned Diffuser
Numerical Analysis of the Fluid Flow in the First Stage of a Two-Stage Centrifugal Pump With a Vaned Diffuser
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DOI：
10.1115/1.4023956
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发表时间：
2013-07
影响因子：
2
通讯作者：
H. Stel;G. Amaral;C. Negrao;S. Chiva;V. Estevam;R. Morales
中科院分区：
文献类型：
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作者：
H. Stel;G. Amaral;C. Negrao;S. Chiva;V. Estevam;R. Morales
本文对带叶片扩压器的双级离心泵第一级内流体流动进行了数值研究。计算流体动力学（CFD）分析是通过使用theANSYS-CFX软件进行了广泛的体积流量，也为不同的转子速度。数值计算结果与第一级叶轮和扩压器的压力上升实测值进行了对比验证，总体吻合良好。然而，不仅数值评估的最佳效率点与测量的两级泵值相比被高估，而且第一级的计算水力效率也被高估。对不同流速下的流型进行的研究表明，在部分负荷条件下，流动方向变得很差。在这种情况下，主要在扩压器中观察到显著水平的湍流和叶片定向效应。在无量纲系数不变的情况下，无论流量或转速如何变化，流型都十分相似，这表明经典的相似准则可以应用于这种情况。通过使用这些规则，还可以推导出用于泵压头的单个方程，以表示泵的整个操作范围。
This work presents a numerical investigation of the fluid flow in the first stage of a two-stage centrifugal pump with a vaned diffuser. A computational fluid dynamics (CFD) analysis is performed by using theANSYS-CFXsoftware for a wide range of volumetric flow rates and also for different rotor speeds. The numerical results are validated against measured values of pressure rise through the impeller and diffuser of the first stage with an overall good agreement. Nevertheless, not only the best efficiency point evaluated numerically is overestimated in comparison with the measured two-stage pump values but also the computed hydraulic efficiency of the first stage. Investigation of the flow pattern for different flow rates reveals that the flow becomes badly oriented for part-load conditions. In such cases, significant levels of turbulence and blade orientation effects are observed, mainly in the diffuser. In spite of different flow rates or rotor speeds, the flow pattern is quite similar if the flow dimensionless coefficient is kept constant, showing that classical similarity rules can be applied in this case. By using such rules, it was also possible to derive a single equation for the pump head to represent the whole operational range of the pump.