Numerical simulation on macro-instability of coupling flow field structure in jet-stirred tank

[摘要] The velocity field macro-instability (MI) can help to improve the mixing efficiency. In this work, the MI features of flow field induced by jet-stirred coupling action is studied by using computational fluid dynamics (CFD) simulations. The numerical simulation method of jet-stirred model was established based on standard turbulent equations, and the impeller rotation was modeled by means of the Sliding Mesh (SM) technology. The numerical results of test fluid (water) power consumption were compared with the data obtained by power test experiments. The effects of jet flow velocity and impeller speed on MI frequency were analyzed thoroughly. The results show that the calculated values of power consumption agree well with the experiment measured data, which validates the turbulent model, and the flow structure and MI frequency distribution are affected by both impeller speed and jet flow rate. The amplitude of MI frequency increases obviously with the increasing rotation speed of impeller and the eccentric jet rate, and it can be enhanced observably by eccentric jet rate, in condition of comparatively high impeller speed. At this time, the MI phenomenon disappears with the overall chaotic mixing.

[发布机构] School of Mechanical and Electrical Engineering, Qingdao University of Science and Technology, China^1

[效力级别] 工业技术 [学科分类] 工业工程学

[关键词] Calculated values;Computational fluid dynamics simulations;Frequency distributions;Impeller rotation;Macro instabilities;Mixing efficiency;Numerical results;Numerical simulation method