Experimental measurement and computational fluid dynamics simulation of mixing in a stirred tank: a review

Authors

  • A. Ochieng Department of Chemical Engineering, Vaal University of Technology, Private Bag X021, Vanderbijlpark 1900, South Africa.
  • M. Onyango
  • K. Kiriamiti Department of Chemical and Process Engineering, Moi University, P.O. Box 3900, Eldoret, Kenya.

Abstract

Stirred tanks are typically used in many reactions. The quality of mixing generated by the impellers can be determined using either experimental and simulation methods, or both methods. The experimental techniques have evolved from traditional approaches, such as the application of hot-wire anemometry, to more modern ones like laser Doppler velocimetry (LDV). Similarly, computational fluid dynamics (CFD) simulation techniques have attracted a lot of attention in recent years in the study of the hydrodynamics in stirred tanks, compared to the empirical modelling approach. Studies have shown that the LDV technique can provide very detailed information on the spatio-temporal variations in a tank, but the method is costly. For this reason, CFD simulation techniques may be employed to provide such data at a lower cost. In recent years, both integrated experimental and CFD approaches have been used to determine flow field and to design various systems. Both CFD and LDV data reveal the existence of flow maldistribution caused by system design features, and these in turn show that the configurations that have, over the years, been regarded as standard may not provide the optimal operating conditions with regards to the system homogeneity and power consumption. The current trends in CFD studies point towards an increasing application of more refined grids, such as in large eddy simulation, to capture turbulent structures at microscales. This trend will further improve the quality of the simulation results for processes such as precipitation, in which micromixing and reaction kinetics are important.

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Published

2010-02-02

Issue

Section

Review Articles

How to Cite

Ochieng, A., Onyango, M., & Kiriamiti, K. (2010). Experimental measurement and computational fluid dynamics simulation of mixing in a stirred tank: a review. South African Journal of Science, 105(11/12), 421-426. https://sajs.co.za/article/view/10225
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