Simulating orthokinetic heterocoagulation and cluster growth in destabilizing suspensions--颗粒学报PARTICUOLOGY

Bülow, F., Nirschl, H., & Dörfler, W. (2017). Simulating orthokinetic heterocoagulation and cluster growth in destabilizing suspensions. Particuology, 31, 117-128. https://doi.org/10.1016/j.partic.2016.07.005

Simulating orthokinetic heterocoagulation and cluster growth in destabilizing suspensions

Fabian Bülow^a^b *, Hermann Nirschl ^a, Willy Dörfler ^b

a Institute of Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
b Institute for Applied and Numerical Mathematics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany

10.1016/j.partic.2016.07.005

Volume 31, April 2017, Pages 117-128

Received 21 October 2015, Revised 9 June 2016, Accepted 6 July 2016, Available online 26 November 2016, Version of Record 9 March 2017.

E-mail: fabian.buelow@kit.edu

Highlights

• Destabilization behavior of orthokinetic heterocoagulation suspensions was investigated.

• Classical binary and multi-particle approaches were presented.

• Capture efficiency expression for polydisperse particle system was derived.

• Derivation and usage of the (global) capture efficiency were discussed.

• Destabilization experiments of more than 2 particles and cluster detection were performed.

Abstract

Using direct numerical simulation, we investigate the coagulation behavior of non-Brownian colloidal particles as exemplified by Al₂O₃ particles. This yields the so-called capture efficiency, for which we give an analytical expression, as well as other time-dependent variables such as the cluster growth rate. Instead of neglecting or strongly approximating the hydrodynamic interactions between particles, we include hydrodynamic and non-hydrodynamic interactions in a Stokesian dynamics approach and a comprehensive modeling of the interparticle forces. The resulting parallelized simulation framework enables us to investigate the dynamics of polydisperse particle systems composed of several hundred particles at the same high level of modeling we used for a close investigation of the coagulation behavior of two unequal particles in shear flow. Appropriate cluster detection yields all the information about large destabilizing systems, which is needed for models used in flow-sheet simulations. After non-dimensionalization, the results can be generalized and applied to other systems tending to secondary coagulation.

Graphical abstract

Keywords

Destabilization; Coagulation; Capture efficiency; Al₂O₃; Cluster detection; Stokesian dynamics

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