共查询到19条相似文献,搜索用时 375 毫秒
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k-ε涡粘湍流模型用于离心泵数值模拟的适用性 总被引:13,自引:0,他引:13
以IS80-65-160离心泵为研究对象,对设计工况和八种非设计工况进行了整机系列相对位置定常流动数值模拟.计算中分别采用标准k-ε模型、RNG缸k-ε模型和Realizable k-ε模型三种k-ε涡粘湍流模型,以考察比较它们对离心泵内流模拟计算的适用性.计算中考虑了叶轮和蜗壳之间相对位置变化对流场的影响,较全面反映叶轮与蜗壳间的相互作用.在数值模拟的基础上,计算了基于三种湍流模型的扬程、轴功率、效率及性能曲线,并与试验性能曲线进行对比.研究表明:三种肛k-ε涡粘湍流模型均可用于离心泵内部流动数值模拟计算,采用Realizable k-ε模型的离心泵仿真结果与试验吻合最好. 相似文献
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本文基于N-S方程和标准k-ε紊流模型,对LB50-160型离心泵设计流量下叶轮内流场三维紊流进行了数值计算,获得了叶轮内流场的速度、压力分布,捕捉到了一些重要的流动现象。并对数值计算结果进行了深入的分析研究,为叶轮的水力设计提供了有价值的信息。对叶轮结构进行了有限元分析,准确且直观的得到了叶轮在载荷作用下的应力和应变,为叶轮的强度计算提供了可靠依据。 相似文献
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运用ANSYS CFX软件对LMV-311型高速离心泵内部流场进行三维数值模拟。应用标准k-ε紊流模型对离心泵叶轮内部的三维紊流流动进行雷诺Navier-Stokes方程的数值计算与分析。揭示了叶轮内紊流流动的速度、压力分布规律,对叶轮内部的流动状况进行了研究与分析,从而为半开式叶轮高速离心泵的优化设计奠定了基础。 相似文献
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通过对100QJ 3.2型高速深井离心泵在不同网格数、不同湍流模型、不同模拟级数条件下进行三维定常数值模拟,分析了不同条件对其性能的影响,从而选出合适的数值模拟设置方法。将性能预测结果与样机试验结果对比,验证利用CFX软件预测高速深井离心泵性能的可行性。结果表明:采用叶轮网格数为40万、Standard k-ε湍流模型、两级全流场模型对高速深井离心泵进行全流场三维定常数值模拟最为合适。 相似文献
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Analysis on the inner flow field of a centrifugal pump impeller with splitter blades is carried out by numerical simulation. Based on this analysis, the principle of increasing pump head and efficiency are discussed. New results are obtained from the analysis of turbulence kinetic energy and relative velocity distribution: Firstly, unreasonable length or deviation design of the splitter blades may cause great turbulent fluctuation in impeller channel, which has a great effect on the stability of impeller outlet flow; Secondly, it is found that the occurrence of flow separation can be decreased or delayed with splitter blades from the analysis of blade loading; Thirdly, the effect of splitter blades on reforming the structure of "jet-wake" is explained from the relative velocity distribution at different flow cross-sections, which shows the flow process in the impeller. The inner flow analysis verifies the results of performance tests results and the PIV test. 相似文献
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低比转速开式叶轮高速离心泵的优化设计系统 总被引:7,自引:0,他引:7
提出基于Navier-Stokes方程和Spalart-allmaras湍流模型流动分析的低比转速开式叶轮高速离心泵优化设计系统,该系统由四个部分组成:基本参数的优化设计、性能预测、流动分析和信息反馈。根据提出的方法,对一台开式叶轮高速离心泵进行实例设计和实验研究,取得了较好的性指指标:泵的扬程流量H-qv特性线几乎是一条直线,扬程系数达到了0.7以上;汽蚀性能也满足要求;叶轮内部压力和速度分布合理,表明采用加大流量设计方法能设计出性能优异的低比转速开式叶轮高速离心泵,此设计方法是合理可行的,对开式叶轮高速离心泵的设计具有指导意义。 相似文献
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为分析叶轮结构对于叶轮内部流动的影响,对8叶片的闭式和半开式两种形式低比转速高速离心复合叶轮进行研究.采用S-A湍流模型和雷诺时均N-S方程,对叶轮内部的流动进行三维紊流数值计算和分析,并对离心泵进行试验研究.数值计算结果表明,两种形式叶轮内部都存在回流,其中半开式叶轮内部的回流区域较少,液流在间隙里的相对流动大致为圆周方向;叶轮内部的静压力都是由叶片进口到出口逐渐升高,等静压曲线几乎是沿圆周方向,半开式叶轮叶片顶部的静压力低于相应位置根部的静压力,闭式叶轮出口的压力系数高于半开式叶轮.试验结果表明,半开式叶轮离心泵的效率较高,说明叶轮内部的回流是影响离心泵性能的重要因素. 相似文献
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《机械工程学报(英文版)》2010,(6)
The blade number of impeller is an important design parameter of pumps,which affects the characteristics of pump heavily.At present,the investigation focuses mostly on the performance characteristics of axis flow pumps,the influence of blade number on inner flow filed and characteristics of centrifugal pump has not been understood completely.Therefore,the methods of numerical simulation and experimental verification are used to investigate the effects of blade number on flow field and characteristics of a centrifugal pump.The model pump has a design specific speed of 92.7 and an impeller with 5 blades.The blade number is varied to 4,6,7 with the casing and other geometric parameters keep constant.The inner flow fields and characteristics of the centrifugal pumps with different blade number are simulated and predicted in non-cavitation and cavitation conditions by using commercial code FLUENT.The impellers with different blade number are made by using rapid prototyping,and their characteristics are tested in an open loop.The comparison between prediction values and experimental results indicates that the prediction results are satisfied.The maximum discrepancy of prediction results for head,efficiency and required net positive suction head are 4.83%,3.9% and 0.36 m,respectively.The flow analysis displays that blade number change has an important effect on the area of low pressure region behind the blade inlet and jet-wake structure in impellers.With the increase of blade number,the head of the model pumps increases too,the variable regulation of efficiency and cavitation characteristics are complicated,but there are optimum values of blade number for each one.The research results are helpful for hydraulic design of centrifugal pump. 相似文献
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螺旋离心泵叶轮背叶片对轴向力影响的数值分析 总被引:2,自引:0,他引:2
基于相对坐标系下的雷诺时均N-S方程和RNG k-湍流模型,采用非结构化混合网格技术和SIMPLEC算法,以清水为介质,对带有叶轮背叶片的80LN-6型螺旋离心泵进行全三维数值模拟。通过改变叶轮背叶片数目和宽度设计出6种不同螺旋离心泵叶轮方案,对各种方案下泵内流动进行数值模拟,获得螺旋离心泵叶轮无背叶片和不同背叶片数目及宽度下轴向力的变化趋势和规律。通过对外特性试验数据和CFD数值模拟数据对比,间接地验证了数值模拟方法的可靠性。并对6种不同螺旋离心泵叶轮方案模拟数据进行分析,结果表明,螺旋离心泵添加叶轮背叶片之后,轴向力大小发生变化,同时在不同方案中不同工况下轴向力方向也发生改变;背叶片数目、背叶片宽度对于平衡轴向力均存在最优值且对后腔及蜗壳内的压力分布有较大影响。 相似文献
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Numerical simulation and analysis of flow characteristics in the front chamber of a centrifugal pump
Yang Wu Xiaoping Chen Hua-Shu Dou Lulu Zheng Zuchao Zhu Baoling Cui Boo Cheong Khoo 《Journal of Mechanical Science and Technology》2017,31(11):5131-5140
We performed numerical simulations to study the flow characteristic in a centrifugal pump based on the RANS equations and the RNG k-ε turbulent model. The flow field, including the front and back pump chambers, the impeller wear-ring, the impeller passage, the volute casing, the inlet section and outlet section was calculated to obtain accurate numerical results of fluid flow in a centrifugal pump. The flow characteristic was studied from the internal flow structure in pump chambers, the radial velocity at impeller outlet as well as the pressure inside of the pump, the circumferential velocity and the radial velocity in front pump chamber. The variation of flow parameters in internal flow versus flow rate in the centrifugal pump was analyzed. The results show that the overall performance of the pump is in good agreement with the experimental data. The simulation results show that the distribution of flow field in the front pump chamber is axial asymmetry. The energy dissipation at the impeller outlet is larger than other areas. The distribution of the circumferential velocity and that of radial velocity are similar along the axial direction in the front pump chamber, but the distribution of flow is different along the circumferential and the radial directions. It was also found that the vorticity is large at the impeller inlet compared with other areas. 相似文献