PIV experiment and numerical simulation of improved INTER-MIG impeller vortex structure
LIN Weizhen1, ZHOU Yongjun1*, WANG Lulu1, TAO Lanlan2
1. College of Mechanical and Power Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816, China; 2. National Quality Supervision & Inspection Center of Chemical Equipment, Special Equipment Safety Supervision Inspection Institute of Jiangsu Province, Suzhou, Jiangsu 215600, China
Abstract：The trailing vortices around an improved INTER-MIG impeller were investigated in a stirred tank using particle image velocimeter(PIV)and computational fluid dynamics(CFD). The numerical simulation results were compared with the PIV experiments and the differences of several turbulence models were analyzed. The vorticity of trailing vortex structure was analyzed by 2D-PIV and the effect of impeller diameter on the trailing vortex was discussed. The results show that the LES is better than the Reynolds average for the prediction of the trailing vortex. The improved INTER-MIG impeller ge-nerates an asymmetrical trailing vortex during motion, the lower vortex of the impeller is formed before the upper vortex, and the maximum vorticity of lower vortex is higher than the upper vortex. In the process of forming the trailing vortex to the maximum, the diameter of impeller has a great influence on the radial displacement of the lower vortex. When D=0.57T, the speed of the trailing vortex is the fastest in the radial direction and the turbulent kinetic energy is the largest. When the trailing vortex begins to decay, the larger the diameter of the blade,the faster the tail vortex dissipates. The maximum value of turbulent kinetic energy is located between the two vortexes, which increases with the deve-lopment of trailing vortexes and decreases with the decline of trailing vortexes. The research results reveal the stirring mechanism in stirred tank with the improved INTER-MIG impeller, and can provide reference for the engineering application and optimization design of stirred tank with the improved INTER-MIG impeller.
