【作者】 钱健；

【导师】 刘超；

【作者基本信息】 扬州大学 ， 水利水电工程， 2003， 硕士

【摘要】 离心泵是一种通用水力机械，其内部流动情况一直是泵设计人员十分关注的问题，因为泵内流动的优劣直接影响泵的性能。离心泵叶轮的内部流动是很复杂的三维紊流流动，同时由于受旋转和叶片表面曲率的影响还拌有脱流、回流及二次流的现象，是流体工程中较难的试验研究和数值计算问题之一。 早在20世纪50年代，一些专家学者就开始尝试使用数值计算方法来预测叶轮中的流动情况。但具有完备形态的内流数值模拟，一般认为始于吴仲华教授的S1、S2两类相对流面理论后，叶轮机械内流数值模拟才得到了迅速发展。迄今为止，国内许多学者已经对离心泵叶轮内部三维紊流数值模拟进行了研究，也取得了一些成果，但并不理想，也缺少实验验证。近年来得益于计算机技术的高速发展，计算流体力学CFD(Computational Fluid Dynamics)发展很快，许多商用CFD软件应用非常广泛，在离心泵内部流场数值模拟上的应用也日见增多。通过CFD方法对离心泵叶轮内部流动进行数值模拟，了解液流在叶轮过流部件中的速度和压力分布，从而进行叶片的选型、设计和性能预测已成为现代泵技术的重要方法之一。 本文基于N—S方程和标准的k—ε双方程紊流模型，采用商用CFX-TASCflow计算软件对一离心泵叶轮模型进行了叶轮内部三维紊流数值模拟，得到了三个典型工况下、从轮毂到前盖板每一个断面上的速度和压力分布。通过与该叶轮内流场的激光粒子图象速度场仪——PIV(Particle Image Velocitymeter)实验结果比较，初步分析了离心泵叶轮的汽蚀和能量特性，为进一步完善泵设计理论、提高泵设计水平提供有益的参考。 本文得到国家自然科学基金项目“水泵转轮内流场激光测量研究”(No．59949010)的资助。更多还原

【Abstract】 Centrifugal pump is a commonly hydraulic machine, whose inner flow has direct influence on pump’s performance and is a considered problem by the pump designers. with the phenomena of dropping flow, backflow and secondary flow effected by circulation and surface curvature, the centrifugal pump’s inner flow is very complicated 3d flow . Therefore, the centrifugal pump inner flow is one of the difficult problems both in testing research and numeric computation .In the 1950s, some experts and scholars tried to use numeric computation method to predict the blade’s inner flow. But it is thought that the mature pump inner flow numeric computation was started and then developed rapidly after the "two relative flow surface" (the S1 and S2) theory presented by professor Wuzhonghua. From then on, many domestic scholars have made much research on the numeric simulation of the centrifugal pump inner 3D turbulent, and they have made some progress, which were yet short of enough validation through experiment. In recent years, with the rapid development of the computer technology, CFD (computational fluids dynamics) develops rapidly, and many commercial computation softwares are applied widely. Some softwares have been used to compute the centrifugal pump inflow. Through the numeric simulation of the centrifugal pump inner flow by CFD, the distribution of the velocity and pressure in the pump are conducted to impeller design and hydraulic performance prediction, which has become one of the important modern pump design method.In this paper, based on the Navier-Stokes equation and the k- turbulent model, the numerical simulation of the 3D turbulent flow in a centrifugal impeller, of which specific speed is 93. The distribution of the velocity and pressure in the blade-to-blade passage are presented at the design and off-design operating conditions. The simulation results were verifiable with the results measured by PIV. This study can be very helpful to improve and optimize the impeller design.更多还原