Numerical simulation of distributive mixing in 3‐D flows

Abstract

A numerical simulation is performed for analysing the mixing of the stirring tank. The influence of the stirring tank geometry and of the Reynolds number is investigated. Statistical tools are used for predicting the evolution of quantities such as area stretch and global mixing efficiency.

Examination of the mixing ability of single and twin screw mixers using 2D finite element method simulation with particle tracking

“…The mesh superposition technique (Avalosse, 1996;Polyflow, 2003a) can be considered a simplification of the fictitious domain method (Bertrand et al, 1997;Bertrand, Thibault, Delmare, & Tanguy, 2003). This technique meshes the flow domains and moving elements separately and superimposes the meshes as they would be positioned at a given time interval as shown in Fig.…”

3D numerical simulation of the flow of viscous newtonian and shear thinning fluids in a twin sigma blade mixer

“…MST 20,23 allows the use of a periodically changing geometry without remeshing with the twin screw simulations. This is accomplished by meshing the flow domains and moving elements separately and superimposing the meshes as they would be positioned at a given time interval.…”

“…20 MST involves separately meshing the flow domain and the moving elements and superimposing them at set time intervals with a penalty formulation of the governing equations used to impose the velocity of the moving parts. Avalosse and Rubin 21 used MST as implemented using the finite element method (FEM) by Polyflow (Fluent Inc.) in order model the flow and mixing in 3D in a single screw and twin screw extruder.…”

Mixing simulation of a viscous Newtonian liquid in a twin sigma blade mixer

“…The mesh superposition technique 12,13,24 was used to account for the movement of the sigma blades. The final bowl mesh was chosen after a preliminary study with the corn syrup fluid model at the initial blade position that examined the problem size, solution time and convergence for a series of bowl meshes containing from 13,872 to 62,034 elements.…”

“…Recently, computational fluid dynamics (CFD) finite element method (FEM) numerical simulation techniques have been developed that greatly simplify the issue of mesh creation in a constantly changing geometry by separately meshing the mixing domains and mixing elements, and then superimposing them at a given position. Avalosse 13 introduced the mesh superposition technique (MST), which involves separately meshing the flow domain and the moving elements, and then superimposing them at set time intervals with a penalty formulation of the governing equations used to impose the velocity of the moving parts. MST was used with particle tracking to calculate in 3-D the velocity profile, distributive mixing efficiency and cluster distribution index in a stirred tank with and without baffles for several Reynolds numbers.…”