共查询到19条相似文献,搜索用时 140 毫秒
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本文基于三维雷诺时均的Navier—Stokes方程和标准的k—ε湍流模型,采用三维无结构网格及压强连接的隐式修正SIMPLEC算法,利用Fluent中提供的多重参考系(MRF)模型,分别对IB型离心泵的叶轮与整机流道进行内部流动的数值模拟,根据计算结果分析离心泵蜗壳对叶轮内部流动的影响,揭示离心泵内的流动规律。对离心泵性能的预测值与实验值作了比较以验证计算结果的正确性。 相似文献
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利用数值流体动力学CFD(computational fluid dynamics)商业软件Fluent对高速离心油泵叶轮内部的定常三维湍流进行了全流道数值模拟,以研究其内部流动规律。数值计算基于Reynolds时均N-S方程,采用了标准k-ε湍流模型和SIMPLEC算法。由于计算域由转动的叶轮和固定的蜗壳组成,使用了多重参考坐标系(MRF)把旋转区域和静止区域分开。计算得到了叶片吸力面和压力面等值线图、叶轮全流道截面(z=0)压力分布云图、叶轮全流道截面(z=0)相对速度矢量图;并对叶轮小流量工况和大流量工况进行计算。根据计算的数据对泵的外特性进行预估,给出了泵的扬程流量特性曲线、功率流量特性曲线。计算结果有助于深入了解叶轮的内部流动机理,指导叶轮的水力设计。 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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基于ANSYS的离心叶轮内流场的数值模拟 总被引:1,自引:0,他引:1
基于N-S方程和标准κ-ε紊流模型,利用有限元分析软件ANSYS的CFD模块,对离心象叶轮内三维紊流进行了数值模拟。获得了离心泵叶轮内的流速、压力场分布,捕捉到了一些重要的流动现象。 相似文献
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利用CFD软件Fluent对多级导叶式清水离心泵的内部流场进行了数值模拟,得出了叶轮及导叶内部流道的速度和压力分布规律,并发现了叶轮进口回流,出口的二次流动特征等叶轮内部流动的细节,导叶出口区产生了一个低压区等流动特征。然后根据自编计算软件利用计算得到的速度场数据计算出泵的扬程、功率、效率和流量之间的关系曲线,并与试验数据进行了比较。结果表明:在设计工况附近,预测值与试验值吻合较好,在其它工况点,特别是小流量工况点,误差较大。 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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为研究超低比转速复合式离心泵内部流动特性,以一台比转速为16、半开式复合叶轮离心泵为研究对象,应用ANSYS-Fluent19R1软件对模型泵进行三维全流场数值模拟计算,得出泵内部流场及作用在叶轮、蜗壳上的径向力分布规律。结果表明:在不同流量工况下,随着流量的增加,在隔舌附近出现较大的压力梯度;在长叶片与短叶片相间隔流道内低速区面积较大、叶轮出口处分布较多的旋涡;当流量从0.2倍增加至1.8倍额定流量时,作用在蜗壳上的径向力幅值逐渐减小,作用在叶轮上的径向力幅值先减小后增加,在1.0倍额定流量时径向力幅值达到最小,而后增大。为超低比转速复合式离心泵的设计优化提供参考。 相似文献
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介绍了低比速离心泵特点,阐述计算的控制方程和叶轮通道网格划分方法.运用CFD软件FLUENT对不同叶片形式叶轮流道进行三维湍流流动计算.计算采用压强连接的隐式修正SIMPLEC算法和雷诺平均法的RNG k-ε湍流模型.根据计算结果分析叶片形式对流速分布、压力分布的影响,揭示叶轮内流动规律,提高低比速离心泵优化设计的水平. 相似文献
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Evaluation of subgrid-scale models in large-eddy simulations of turbulent flow in a centrifugal pump impeller 总被引:4,自引:1,他引:4
The current research of large eddy simulation (LES) of turbulent flow in pumps mainly concentrates in applying conventional subgrid-scale (SGS) model to simulate turbulent flow, which aims at obtaining the flow field in pump. The selection of SGS model is usually not considered seriously, so the accuracy and efficiency of the simulation cannot be ensured. Three SGS models including Smagorinsky-Lilly model, dynamic Smagorinsky model and dynamic mixed model are comparably studied by using the commercial CFD code Fluent combined with its user define function. The simulations are performed for the turbulent flow in a centrifugal pump impeller. The simulation results indicate that the mean flows predicted by the three SGS models agree well with the experimental data obtained from the test that detailed measurements of the flow inside the rotating passages of a six-bladed shrouded centrifugal pump impeller performed using particle image velocimetry (PIV) and laser Doppler velocimetry (LDV). The comparable results show that dynamic mixed model gives the most accurate results for mean flow in the centrifugal pump impeller. The SGS stress of dynamic mixed model is decompose into the scale similar part and the eddy viscous part. The scale similar part of SGS stress plays a significant role in high curvature regions, such as the leading edge and training edge of pump blade. It is also found that the dynamic mixed model is more adaptive to compute turbulence in the pump impeller. The research results presented is useful to improve the computational accuracy and efficiency of LES for centrifugal pumps, and provide important reference for carrying out simulation in similar fluid machineries. 相似文献
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液压系统与电-机械系统是广泛应用于航空航天、工业、非道路移动机械等领域的两种不同驱动方案。在实际中,两者通常单独使用,电-机械驱动方案能效高,但承载能力弱,液压驱动方案功率密度大、动态响应快,但能量效率低。为此,结合两个驱动方案优点,集成设计电-机械执行器与液压缸,构建一种新型液电混合直线驱动系统,分析系统工作原理及两个非相似驱动子系统耦合特性、力纷争现象及其影响。在此基础上,提出一种电-机械驱动单元运动控制与液压驱动单元力控制的调控方案。研究结果表明,采用所提调控方案可减轻两个非相似驱动子系统耦合作用,在液压阀低压损的同时,可获得良好的位置控制特性。新型液电混合直线驱动系统将为液压系统和电-机械系统的进一步发展提供新思路。 相似文献
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