Rev Chem Eng 2015; 31(2): 119–147 *Corresponding author: Abdul Aziz Abdul Raman: Faculty of Engineering, Department of Chemical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia, e-mail: azizraman@um.edu.my Raja Shazrin Shah Raja Ehsan Shah and Baharak Sajjadi: Faculty of Engineering, Department of Chemical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia http://orcid.org/0000-0001-5147-7667 (Raja Shazrin Shah Raja Ehsan Shah) Shaliza Ibrahim: Faculty of Engineering, Department of Civil Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia Raja Shazrin Shah Raja Ehsan Shah, Baharak Sajjadi, Abdul Aziz Abdul Raman* and Shaliza Ibrahim Solid-liquid mixing analysis in stirred vessels Abstract: This review evaluates computational fluid dynamic applications to analyze solid suspension quality in stirred vessels. Most researchers typically employ either Eulerian-Eulerian or Eulerian-Lagrangian approach to investigate multiphase flow in stirred vessels. With suf- ficient computational resources, the E-L approach simu- lates flow structures with higher spatial resolution for dispersed multiphase flows. Common turbulence models such as the two-equation eddy-viscosity models (k-ε), Reynolds stress model, direct numerical simulation, and large eddy simulation are described and compared for their respective limitations and advantages. Litera- ture confirms that k-ε is the most widely used turbulence model, but it suffers from some inherent shortcomings due to assumption of isotropy of turbulence and homog- enous mixing. Subsequently, the importance of different forces concerning solid particle flotation is concluded. Studies on dilute systems take into account only drag and turbulence forces while other forces have always been ignored. The simulations of off-bottom solid suspension, solid drawdown, solid cloud height, solid concentration distribution, and particle collision are considered for studies involving solid suspension. Different models and methods applied to investigate the abovementioned phe- nomena are also discussed in this review. Keywords: computational fluid dynamics (CFD); drag force; solid suspension; stirred vessel. DOI 10.1515/revce-2014-0028 Received July 2, 2014; accepted December 16, 2014; previously pub- lished online February 26, 2015 Abbreviations ALE Arbitrary Lagrangian-Eulerian CARPT Computer automated radioactive particle tracking CFD Computational fluid dynamics DNS Direct numerical simulation E-E Eulerian-Eulerian E-G Eulerian-Granular E-L Eulerian-Lagrangian k-ε Two-equation Eddy-viscosity LES Large eddy simulation MRF Multiple reference frames PDF Probability density function RANS Reynolds averaged Navier-Stokes RNG Renormalization group k-ε RSM Reynolds stress model SG Sliding grid 1 Introduction Turbulently agitated vessels where a solid-liquid sus- pension is produced account for approximately 80% of all industries and are common in leaching process, crystallization process, catalytic reactions, bio-slurry processes, mineral processing, precipitation, coagula- tions, dissolution, water treatment, and a variety of other applications (Špidla et al. 2005). Optimum performance, accurate control, and reliable design of these equip- ment are highly dependent on thorough understanding of several phenomena such as turbulence, local dis- persed concentration distribution, fluid flow dynamics, system composition, and different equipment configura- tions (Leng and Calabrese 2004). At present, computa- tional fluid dynamics (CFD) has emerged as an effective and powerful mean in both applied and fundamental research to predict local fluid dynamics, chemical reac- tions, and related phenomena such as heat and mass transfer in tanks (Van den Akker 2006). However, hydro- dynamic simulation in stirred vessels is very complex due to the interaction between the rotating impeller with multiphase dispersion and highly unsteady field of flow. Brought to you by | University of Malaya Library Authenticated | azizraman@um.edu.my author's copy Download Date | 1/21/16 2:17 PM