基于DEM-CFD的旋流泵大颗粒内流特性模拟与试验  

Simulation and Experiment on Flow Characteristics of Large Particles in Vortex Pump Based on DEM-CFD

作　　者：施卫东 施亚 高雄发[2] 张德胜[2] 郎涛[2] 赵婷 SHI Weidong;SHI Ya;GAO Xiongfa;ZHANG Desheng;LANG Tao;ZHAO Ting(School of Mechanical Engineering,Nantong University,Nantong 226019,China;Research Center of Fluid Machinery Engineering and Technology,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]南通大学机械工程学院,南通226019 [2]江苏大学流体机械工程技术研究中心,镇江212013

出　　处：《农业机械学报》2020年第10期176-185,共10页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51909108、51579118);江苏省“六大人才高峰”高层次创新人才团队项目(JNHB-CXTD-005)。

摘　　要：鉴于抗堵塞性能较优的旋流泵在输送污水时,其过流部件仍存在磨损、半堵塞等问题,将DEM-CFD方法引入旋流泵数值模拟中,研究旋流泵在输送不同粒径、体积分数颗粒时的颗粒运动物理特性,以及颗粒与液相、固壁多向耦合的运动特征,并进行了试验验证。结果表明,由旋流泵输送油菜籽试验可知,外特性计算结果与试验结果基本一致;在该旋流泵模型特征下,进口管与无叶腔区域由循环流引起的颗粒旋转流动现象较为严重,从无叶腔沿着进口壁面螺旋式逆向回流,与进口顺向来流相混达到平衡,试验拍摄结果与数值模拟结果较为相符,说明DEM-CFD耦合方法具有一定可靠性;旋流泵内部存在3种不同的颗粒运输方式,第1种为颗粒随贯通流经由叶轮进入蜗壳,第2种为受循环流影响经由无叶腔直接甩入蜗壳,第3种为颗粒从叶轮前端面区域进入叶轮,再经叶轮进入蜗壳;对蜗壳内流特性进行分析,发现颗粒主要分布在蜗壳后侧,在扩散段到蜗壳出口区域,颗粒随液体以螺旋的方式流出,蜗壳断面叶轮侧形成大小不等的螺旋涡。In recent years,because the anti-clogging ability of swirl pump is better than that of ordinary pumps,it is gradually applied to more fields.However,when transporting sewage contains solids,it will still encounter problems such as half clogging,overwork wear,etc.,so it is particularly important to master the flow characteristics of solid particles in the vortex pump.DEM-CFD coupling method was introduced into the numerical simulation of vortex pump.The movement law of particles in the pump was compared and analyzed when the vortex pump transported solid phase with different particle sizes and concentrations.The results showed that according to the experiment of rapeseed transportation by vortex pump,the calculated results of external characteristics were basically consistent with the experimental results.It was found that under the characteristics of the pump model,the particle rotation and flow caused by the circulation flow were more serious in the inlet pipe and the bladed area.The spiral flow from the chamber was reversed along the inlet wall,and the inlet flow was mixed with the reverse spiral flow to reach a balance.The experimental results were consistent with the numerical simulation results.It can be seen from the experiment that the calculation results of the pump performance were basically consistent with the experimental results,and it was found that the particle circulation and rotation phenomenon caused by the circulation flow existed in the inlet pipe,which was also one of the characteristics of the vortex pump and was consistent with the simulation phenomenon,which proved that the DEM-CFD coupling method had a certain reliability.It was found that there were three different modes of particle transportation in the swirl pump,the first was that particles flowed through the impeller and entered the volute,the second was that particles were directly thrown into the volute through the bladed cavity under the influence of circulation flow,and the third was that particles entered the impeller from the fr

关 键 词：旋流泵 大颗粒 DEM-CFD 高速摄影 涡动力学 数值模拟 

分 类 号：TH311[机械工程—机械制造及自动化]