基于ANSYS的混流泵数值模拟仿真

发布时间：2018-07-14 12:41

【摘要】：混流泵是国民经济部门中应用极为广泛的一种通用水力机械，在农田排灌、石油化工、城市给排水和船舶工业等领域都有着广泛的应用。混流泵中的关键过流部件是叶轮，在叶轮内部流体的流动状态非常复杂，并且叶轮结构与叶轮内部流场之间存在着相互作用，而这种相互作用足以影响叶轮的性能，甚至造成结构破坏。因而，在研究混流泵结构特性时，我们必须将混流泵内部流场与其对叶轮结构的影响考虑进来，从而可以提高混流泵叶轮结构分析的准确性。为此，需要采用流固耦合方法，对混流泵叶轮结构进行静力学分析，为改善叶轮结构的力学性能，也为叶轮叶片形状优化提供理论基础与数值依据。本文利用性能优异的三维绘图软件UG对混流泵全流道及其叶轮实体进行三维建模；利用ANSYS-ICEM软件完成混流泵全流道流体网格，并对叶轮结构的实体模型进行网格划分。并将流场网格导入ANSYS-FLUENT中进行数值模拟，获得混流泵内部流场的流动状态。利用流固耦合技术，将分析所得的流场的静压与叶轮实体结构相结合，获得叶轮静力分析的结果。通过数值分析可以知道设计工况下的叶片吸力面的静压变化比压力面的静压变化明显。叶片吸力面进口处出现一定区域的低压区，该区域容易产生汽蚀现象，，与叶轮发生汽蚀的实际位置相吻合。流体在吸力面上的流速明显大于在压力面上的流速，且从叶轮进口到叶轮出口，叶片表面上的相对速度分布均匀，说明叶片的安放角合理。通过静力学分析结果可以知道，在叶片与前后盖板交接处都会发生应力集中的现象，但叶轮的变形都较小，不足以影响叶轮的正常运转，说明叶轮的设计较为合理。
[Abstract]:Mixed-flow pump is a kind of universal hydraulic machinery which is widely used in national economy departments. It is widely used in fields such as farmland irrigation and drainage, petrochemical industry, urban water supply and drainage, ship industry and so on. The impeller is the key flow component in the mixed-flow pump. The flow state in the impeller is very complicated, and there is an interaction between the impeller structure and the flow field in the impeller, which is sufficient to affect the performance of the impeller. It even causes structural damage. Therefore, in order to improve the accuracy of impeller structure analysis, the internal flow field and its influence on impeller structure must be taken into account when studying the structural characteristics of mixed-flow pump. Therefore, it is necessary to use the fluid-solid coupling method to analyze the impeller structure of the mixed-flow pump in order to improve the mechanical properties of the impeller structure and to provide a theoretical and numerical basis for the shape optimization of the impeller blade. In this paper, the 3D modeling of the flow channel and impeller entity of the mixed flow pump is carried out with UG, and the fluid mesh of the flow channel of the mixed flow pump is completed by using ANSYS-ICEM software, and the solid model of impeller structure is meshed. The flow field was introduced into ANSYS-fluent to get the flow state of the mixed flow pump. The static analysis results of impeller are obtained by combining the static pressure of the flow field with the solid structure of the impeller by using the fluid-solid coupling technique. Through numerical analysis, we can know that the static pressure change of the blade suction surface is more obvious than that of the pressure surface under the design condition. There is a low pressure region at the inlet of the suction surface of the blade, which is prone to cavitation, which is consistent with the actual position of cavitation in the impeller. The velocity of the fluid on the suction surface is obviously higher than that on the pressure surface, and the relative velocity distribution on the blade surface is uniform from the impeller inlet to the impeller outlet, which indicates that the blade placement angle is reasonable. The results of statics analysis show that stress concentration occurs at the junction of the blade and the front cover plate, but the deformation of the impeller is small, which is not enough to affect the normal operation of the impeller, which shows that the design of the impeller is reasonable.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH313

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