- Title
- DEM Simulation of Chain aggregation of magnetizable particles in the presence of van der Waals Force
- Creator
- Islam, Ariful; Neville, Frances; Moreno-Atanasio, Roberto
- Relation
- The 47th Chemeca 2018 Conference. Proceedings of The 47th Chemeca 2018 Conference (Queenstown, NZ 30 September, 2018 - 03 October, 2018) p. 1-12
- Publisher
- Institution of Chemical Engineers
- Resource Type
- conference paper
- Date
- 2018
- Description
- The computational analysis of the formation of magnetic particle chains in the presence of van der Waals force has been presented in this work. A computer code based on the discrete element method (DEM) has been developed to simulate the interaction of micron-sized colloidal magnetic particles. The model includes the interaction between magnetic dipoles, cohesion as simulated by the van der Waals force equation and Brownian forces. Hertz's non-linear contact model was used to obtain realistic particle deformations. In the presence of a magnetic field, magnetic dipoles align in the direction of the applied magnetic field and particles tend to form linear chains. The formation of particle chains was studied for values of magnetic induction between 0.01 and 0.05 T and for solid volume fractions between 0.0038 and 0.2. Particle chain formation was confirmed by analysing the coordination number, which is defined as the number of contacts per particle. The time evolution of the coordination number as a function of the material magnetization was considered to analyse the kinetics of aggregation. The simulations showed that the chain formation process became faster with the increase of both magnetization and the solid volume fraction. However, the disruption of the chain formation process was observed when the applied value of the magnetization was less than 0.1 T and therefore, the van der Waals and Brownian forces controlled the behaviour of the system. This work has shown that, despite the combined action of magnetic and van der Waals interactions, there is a wide range of values of these forces for which aggregation does not occur and thus, this work shows the possibility of using micron-sized particles in applications in which the presence of chains could hinder the functionality of the actual particles.
- Subject
- discrete element method; chain aggregation; magnetic particles
- Identifier
- http://hdl.handle.net/1959.13/1447480
- Identifier
- uon:43155
- Identifier
- ISBN:9781911446682
- Language
- eng
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