共查询到18条相似文献,搜索用时 78 毫秒
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离心泵叶轮中固液两相流动的数值模拟 总被引:6,自引:3,他引:6
针对绿液输送过程中,析出的结盐颗粒物堵塞泵内部流道这一现象,从弄清离心泵叶轮中固液两相流的流态出发,分析叶轮内部流场对结盐的影响。通过商用软件fluent6.1.22,利用混合模型对叶轮内部不可压固液两相流动进行了数值模拟。根据计算结果,对叶轮中两相紊流的速度分布、压力分布进行了分析,初步了解泵在输送含结盐颗粒的固液两相流时,结盐颗粒对液相流场的影响。 相似文献
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应用CFD软件FLUENT对离心泵内部整个三维流场进行数值模拟.在0~1.35Qopt范围内对14个不同工况点的扬程、轴功率和效率等性能参数进行了预测,并根据计算结果绘制了性能曲线.通过对由不同计算域组成的计算结果进行比较,证明了当计算域包含叶轮前后腔及密封环间隙时计算结果更准确、更合理.本文为检验离心泵的性能提供了一种进行"虚拟试验"的方法,在新产品设计开发的过程中具有一定的应用价值. 相似文献
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Numerical simulation and analysis of solid-liquid two-phase flow in centrifugal pump 总被引:5,自引:2,他引:5
The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far.There exist two main problems in the operation of the two-phase flow pumps,i.e.,low overall efficiency and severe abrasion.In this study,the three-dimensional,steady,incompressible,and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics(CFD) code based on the mixture model of the two-phase flow and the RNG k-two-equation turbulence model,in which the influences of rotation and curvature are fully taken into account.The coupling between impeller and volute is implemented by means of the frozen rotor method.The simulation results predicted indicate that the solid phase properties in two-phase flow,especially the concentration,the particle diameter and the density,have strong effects on the hydraulic performance of the pump.Both the pump head and the efficiency are reduced with increasing particle diameter or concentration.However,the effect of particle density on the performance is relatively minor.An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration.The suction side of the blade is subject to much more severe abrasion than the pressure side.The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump,and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps. 相似文献
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针对离心泵内流场特性分析困难的问题,对离心泵流场数值模拟的几何模型建立、模型网格划分和边界条件设定进行了研究,采用计算流体力学方法,获取了在敞水性能条件下离心泵的扬程-流量、效率-流量的变化关系;结合Zwart空化模型,重点对不同有效汽蚀余量时离心泵的空化流场进行了数值模拟,得到了离心泵的内部流线和空泡分布的情况,并与该离心泵机组进行了性能测试实验,最后在此基础之上进行了对比分析。研究结果表明,所采用的数值模拟方法和空化模型合理有效,此结果可为进一步开展离心泵空化监测技术研究提供借鉴。 相似文献
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Numerical simulation and experimental research on the influence of solid-phase characteristics on centrifugal pump performance 总被引:1,自引:0,他引:1
The law governing the movement of particles in the centrifugal pump channel is complicated; thus, it is difficult to examine the solid-liquid two-phase turbulent flow in the pump. Consequently, the solid-liquid two-phase pump is designed based only on the unary theory. However, the obvious variety of centrifugal-pump internal flow appears because of the existence of solid phase, thus changing pump performance. Therefore, it is necessary to establish the flow characteristics of the solid-liquid two-phase pump. In the current paper, two-phase numerical simulation and centrifugal pump performance tests are carried out using different solid-particle diameters and two-phase mixture concentration conditions. Inner flow features are revealed by comparing the simulated and experimental results. The comparing results indicate that the influence of the solid-phase characteristics on centrifugal-pump performance is small when the flow rate is low, specifically when it is less than 2 m3/h. The maximum efficiency declines, and the best efficiency point tends toward the low flow-rate direction along with increasing solid-particle diameter and volume fraction, leading to reduced pump steady efficient range. The variation tendency of the pump head is basically consistent with that of the efficiency. The efficiency and head values of the two-phase mixture transportation are even larger than those of pure-water transportation under smaller particle diameter and volume fraction conditions at the low-flow-rate region. The change of the particle volume fraction has a greater effect on the pump performance than the change in the particle diameter. The experimental values are totally smaller than the simulated values. This research provides the theoretical foundation for the optimal design of centrifugal pump. 相似文献
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Computational analysis of centrifugal pump delivering solid-liquid two-phase flow during startup period 总被引:1,自引:0,他引:1
The transient behavior of centrifugal pumps during transient operating periods, such as startup and stopping, has drawn more and more attention recently because of urgent needs in engineering. Up to now, almost all the existing studies on this behavior are limited to using water as working fluid. The study on the transient behavior related to solid-liquid two-phase flow has not been seen yet. In order to explore the transient characteristics of a high specific-speed centrifugal pump during startup period delivering the pure water and solid-liquid two-phase flow, the transient flows inside the pump are numerically simulated using the dynamic mesh method. The variable rotational speed and flow rate with time obtained from experiment are best fitted as the function of time, and are written into computational fluid dynamics (CFD) code-FLUENT by using a user defined function. The predicted heads are compared with experimental results when pumping pure water. The results show that the difference in the transient performance during startup period is very obvious between water and solid-liquid two-phase flow during the later stage of startup process. Moreover, the time for the solid-liquid two-phase flow to achieve a stable condition is longer than that for water. The solid-liquid two-phase flow results in a higher impeller shaft power, a larger dynamic reaction force, a more violent fluctuation in pressure and a reduced stable pressure rise comparing with water. The research may be useful to tmderstanding on the transient behavior of a centrifugal pump under a solid-liquid two-phase flow during startup period. 相似文献
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低速电驱离心压气机特定工况下内部流场的数值模拟 总被引:1,自引:0,他引:1
以压气机的三维流场作为主要研究对象,离心式径流风机为基础模型,确定车用增压器压气机蜗壳和叶轮大致尺寸参数,在此基础上,建立三维整体装配模型,对其进行了数值模拟,对各种离心压气机模型的性能进行预测,分析不同数量、形态叶片的叶轮对效率性能和内部流场压力速度分布的影响。通过计算结果的校核以确定离心压气机叶轮的合理配置方案,了解该离心压气机特定工况下的内部流动情况,以达到设计目标的要求,并为实现快速设计提供依据。 相似文献