不同叶顶间隙下斜流泵内部流动特性的数值模拟  

Numerical simulation of different blade tip clearances on internal flow characteristics in mixed-flow pump

作　　者：张德胜[1] 沈熙 董亚光 王超超 刘安 施卫东 ZHANG Desheng;SHEN Xi;DONG Yaguang;WANG Chaochao;LIU An;SHI Weidong(National Research Center of Pumps,Jiangsu University,Zhenjiang,Jiangsu 212013,China;School of Mechanical Engineering,Nantong University,Nantong,Jiangsu 226019,China)

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013 [2]南通大学机械工程学院,江苏南通226019

出　　处：《排灌机械工程学报》2020年第8期757-763,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金面上资助项目(51776087,51979125);江苏省重点研发计划项目(BE2015001-3);江苏省产学研前瞻性联合研究项目(BY2015064-08);江苏省333工程项目(2016Ⅲ-2731);江苏省六大人才高峰计划项目(HYGC-008)。

摘　　要：为研究轮缘叶顶间隙对斜流泵性能和流动不稳定特性的影响,基于SST k-ω湍流模型对某斜流泵选取了0,0.25,1.00,2.00 mm 4种尺寸的叶顶间隙进行数值计算,分析间隙区域内压差分布、泄漏量、叶顶泄漏涡旋强度以及进口轴面速度分布.结果表明:不同运行工况下,斜流泵泄漏量从叶轮进口到叶轮出口先增大后减小,其与间隙区内压差变化趋势相吻合.叶顶泄漏量随着间隙尺寸的增大而增大,导致泵的能量损失增大.经对比发现,间隙尺寸是影响叶顶泄漏量的主要因素.小流量工况下,随着叶顶间隙尺寸的增大,叶顶泄漏流与主流卷吸作用形成的泄漏涡强度逐渐增强.部分泄漏流进入相邻叶片通道,导致其流动失稳.随着叶顶间隙的增大,斜流泵能量损失明显增多,且内流不稳定性明显加剧.增大流量后,不同间隙下叶顶泄漏涡旋转强度均逐渐降低.To investigate the effects of tip clearance on the performance and unsteady flow in the mixed-flow pump,four sizes of tip clearances(0,0.25,1.00,2.00 mm)were selected to conduct simulation calculation based on SST k-ω turbulence model.The pressure difference distribution,lea-kage flow rate,inlet axial velocity distribution and tip leakage vortex rotation intensity were analyzed.The results show that the leakage of the model pump from impeller inlet to impeller outlet shows a ten-dency that increases first and then decreases under different operating conditions,which is the same as the variation trend of pressure difference in the clearance.With the increase of the clearance size,the leakage of the blade tip also increases,which leads to the increase of the energy loss of the pump.It is found by comparison that the clearance size is the main factor affecting the leakage.Under the part-loading conditions,the rotation intensity of the leakage vortex formed by the interaction between blade tip leakage flow and main flow gradually increases with the increase of blade tip clearance.Part of lea-kage flow enters the passage of adjacent blades,leading to flow instability.As a result,the energy loss and flow instability of the pump show an increasing trend with the increase of clearance size.With the increase of flow rate,the rotation intensity of tip leakage vortex gradually decreases at different clearances.

关 键 词：斜流泵 叶顶间隙 叶顶泄漏涡 不稳定特性 轴面速度 

分 类 号：TH314[机械工程—机械制造及自动化] S277.9[农业科学—农业水土工程]