翼型桨叶片尾涡结构的PIV实测与LES模拟研究  

Measurement of Trailing Vortices around a Hydrofoil Impeller with PIV and Large Eddy Simulation

作　　者：蔡清白[1,2] 戴干策[2] 

机构地区：[1]上海华谊集团技术研究院,上海200241 [2]华东理工大学化学工程联合国家重点实验室,上海200237

出　　处：《过程工程学报》2011年第4期541-548,共8页The Chinese Journal of Process Engineering

摘　　要：在塔径383mm、高径比为1的翼型桨搅拌反应器内,采用粒子图像测速(PIV)技术和大涡模拟(LES)研究了一种翼型桨的叶片尾涡结构.对比二维PIV技术测定的翼型桨搅拌反应器平均速度场数据,验证了LES方法的可靠性.并通过叶片端的速度矢量场、叶片区内的涡量大小及湍动能分布清楚地识别了翼型桨叶片尾涡结构.发现该叶片尾涡为单涡结构,其尾涡轴心轨迹几乎就在桨叶尖划过的圆柱面上.此外,还探讨了叶片尾涡对湍动能分布、湍流特性等的影响,表明最大无因次湍动能k/Vtip2约为0.04～0.06,其位置约在0.5<Z/DT<0.67和0.3<r/R<0.4处,可优化混合过程.The trailing vortices around a hydrofoil impeller were investigated in a 0.383 m i.d. stirred tank with a 0.188 m i.d. hydrofoil impeller using PIV and LES. The comparison between angle-averaged axial velocities by LES and PIV data was in very good agreement, verifying the validity and effectiveness of LES simulation. The presence of trailing vortices formed around the hydrofoil impeller blades were indicated by the mean velocity vectors near the edge of blades, the contours of turbulence levels and kinetic energy of turbulence. It was found that single trailing vortex formed around each blade. The vortex axis was identified to fall on the cylinder swept by the blade tip. The effect of trailing vortices on the turbulence structure was also discussed. The maximum normalized kinetic turbulence energy k/Vtip2 was about 0.04-0.06, which was located at 0.5〈Z/DT〈0.67 and 0.3〈r/R〈0.4. The research results could be used to improve the mixing process.

关 键 词：翼型桨 粒子图像测速 大涡模拟 叶片尾涡 

分 类 号：TQ027.2[化学工程]