Numerical Modelling of Mixability of Highly Viscous Syrup in a U-Shaped Tank with Centrally Rotated Streamers

Document Type : Original Article


1 Professor, Faculty of Engineering Technology, University of Ilorin, Nigeria

2 Lecturer, School of Engineering Technology, Federal Polytechnic Offa, Nigeria

3 Lecturer, Faculty of Engineering, Pan Atlantic University Lekki, Nigeria



This paper numerically analyzed mixing behavior of a malt syrup in a U-shaped tank with a rotating and centrally position streamer. Straight double helical (SDHR), tapered double helical (TDHR) and three-bladed (TBS) streamer’s configurations were investigated. Finite volume method was adopted for the solution. The working fluid is Newtonian while low Reynolds number flow regime was considered. Based on the flow and working fluid adopted, momentum and continuity equations were utilized as the governing equations. CFD code CFX 21.0 was used for the simulations. For the convergence of the solution, the mesh density was one million, six hundred and forty-seven thousand, seven hundred and twenty (1,647,720), and the mesh size was 5 x 10-3 m. The study showed that, rotating at low speed with little blade-wall clearance is needed for proper mixing near the tank wall. The predicted results elucidated that the SDHR is the most suitable for mixing; however, it consumes more power than the other two types of impeller when subjected to the same rotational speed. The findings of this study were beneficial to the design and construction of impellers for petrochemical and industrial food processing applications.


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