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运用大型通用有限元分析软件ANSYS8.0,对离心叶轮内流场三维紊流进行了分析.获得了叶轮内流场压力分布,确定了叶轮结构分析中液体作用于叶片上的载荷.在此基础上对叶轮结构进行了有限元分析,准确直观地得到了叶轮各处的应力和应变值,为叶轮的强度计算和设计提供了可靠依据. 相似文献
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首先对轴流泵进行了性能实验,然后利用PIV(PaIticle Image Velocimetry,粒子示踪测速仪)测量技术在3个不同工况下对轴流泵叶轮的出口流场进行了测量,得到出口回流和旋涡结构。基于Navier-Stokes方程组和标准k-ε模型,采用SIMPLEC算法对轴流泵叶轮内流场进行数值模拟。计算得到泵的性能曲线与性能实验获得的结果比较吻合,并将计算得到的出口流场速度分布和PIV测量结果进行了比较,两者能较好的符合,从而证明了数值计算的有效性和准确性。进而分析了轴流泵不同流量工况下造成效率降低的原因,得知叶根出口位置的回流随着流量的增加而减少。本结果可以为轴流泵的内流分析和叶轮设计提供参考依据。 相似文献
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基于熵产的侧流道泵流动损失特性研究 总被引:1,自引:0,他引:1
侧流道泵是一种介于容积式泵和离心泵之间的径向式叶片泵。泵内流体以螺旋轨迹方式在叶轮和侧流道中反复运动,整个运动是一种典型的全三维、高湍流强度、空间非对称的湍流流动,因此不可避免地产生较大的流动损失。利用热力学第二定律,基于熵产的流动损失分析方法对一种单级侧流道泵模型湍流流动损失进行研究,主要通过理论和数值计算求解湍流流动过程中增加的熵产,定性分析侧流道泵流动损失出现的位置及分布特点。结果表明,侧流道泵内部流动损失主要与湍流流动增加的熵产有关,而热量交换产生的熵产相对较小,在侧流道泵的损失研究中可以忽略;叶轮流道和侧流道内的湍动耗散率均远远大于直接耗散率;叶轮流道内的损失主要出现在叶轮内缘至0.4 r处,在侧流道内,流动损失主要出现在流道进口、流道中间靠近内缘部分以及出口附近。 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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NUMERICAL SIMULATION OF 3-D DENSE SOLID-LIQUID TWO-PHASE TURBULENT FLOW IN A NON-CLOGGING MUD PUMP 总被引:4,自引:0,他引:4
Yuan ShouqiZhang PeifangZhang JinfengXu WeixingResearch Center of Fluid MachineryEngineering Technology Jiangsu University Zhenjiang China 《机械工程学报(英文版)》2004,17(4):623-627
A mathematical model is set to evaluate the 3-D dense solid-liquid two-phase turbulent flow in a non-clogging mud pump, the flow feature in the impeller channel is simulated with the tool of IPSA. Meanwhile, resort to TECPLOT as the post-processor, the simulation results is visualized. The results show the main flow characteristics: There exists backflow and aberrant velocities at inlet area and a relative velocity slip between two phases; A jet-wake flow pattern is discerned around the shroud-suction side area; The relative velocity vector of solid phase is closer to the pressure surface than that of liquid phase and the trend is more obvious with the increase of diameter; The kinetic energy of turbulence k and the dissipation rate s reach their peaks at the corner of pressure and suction surface. The simulation results show a good agreement with the experimental flow features in the impeller channel, which prove the turbulent model used is valid and provide a theoretical design basis to non-clogging pu 相似文献
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Unsteady Turbulent Simulation and Pressure Fluctuation Analysis for Centrifugal Pumps 总被引:5,自引:0,他引:5
YUAN Shouqi NI Yongyan PAN Zhongyong YUAN Jianping 《机械工程学报(英文版)》2009,22(1):64-69
The pressure fluctuation in the flow passage of both impeller and casing is addressed on design condition. The initial conditions for the unsteady turbulent simulation are resulted from the steady calculations, and the three dimensional unsteady turbulent simulation concerning the rotor-stator interaction is executed by a Navier-Stoke solver embedded with k -ε turbulence model and with appropriate moving interface boundary conditions. Detecting points are distributed in the flow passage in different radial and circumferential positions to capture the static pressure fluctuation character for one cycle of the impeller. The time-domain spectrums show that the static pressure curves are periodic and have five peaks and five valleys. With the radius increasing, the pressure fluctuation peak-to-peak values in the impeller are increasing, and reach the maximum value on the interface. In the casing flow passage, those values are about 7% of local static pressure except some ones near the tongue. The values become decreasingly in the diffuser pipe. The frequency spectrums transformed by fast Fourier transform (FFT) show that the dominant frequency is approximate with the blade passing frequency, and the pressure fluctuations in impeller passage have high frequency content while those in casing ones have no such information. 相似文献
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利用ProE软件对血泵的不同结构进行三维建模,应用计算流体力学(Computational fluid dynamics, CFD)中非定常三维N-S方程,基于非结构网格的有限体积法以及k-ε湍流模型方法数值模拟血泵的全三维内流场。着重计算和分析旋转叶轮转速和锥度变化对血泵流场的影响。仿真试验表明,锥形螺旋轴流血泵转速和锥度都不应过大,否则将会使得流场变得紊乱。转速过大,泵的性能会降低;锥度不应过大,否则不能保证流场平稳。 相似文献
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轴流泵叶轮内部流场大涡模拟及分析 总被引:4,自引:0,他引:4
本文将大涡模拟与基于特征线的有限元分离算法相结合,对轴流泵叶轮内部流场进行了数值分析.为验证算法的准确性和可靠性,对NACA0012翼型在雷诺数Re=800下且攻角为20°时的绕流流动进行计算,成功得到了该流动的双解,计算值与直接数值模拟结果相符.大涡模拟计算得到的轴流泵外特性曲线与y试验数据基本吻合,特别在偏离工况下能较好地反映泵的能量特性,表明大涡模拟有较好的工程应用前景.分析了叶轮的进出口流场速度分布及叶片表面的压力脉动,发现小流量工况时叶轮轮缘附近存在叶道涡和较强的压力脉动,此现象与导水锥段收缩流道造成的叶轮进口轴向速度非均匀分布有关. 相似文献