Virtual Experiments of Particle Mixing Process with the SPH-DEM Model

Area of Science:

• Materials Science
• Chemical Engineering
• Computational Fluid Dynamics

Background:

• Particle mixing is crucial for concrete and composite quality.
• Simulating multi-phase granular flow with high solid content is challenging.

Purpose of the Study:

• To develop and validate a computational model for simulating high-shear mixing of solid particles in a liquid.
• To investigate the effects of liquid properties and mixer design on mixing homogeneity.

Main Methods:

• Combined Discrete Element Method (DEM) for solid particles and Smoothed Particle Hydrodynamics (SPH) for liquid particles.
• Implemented two-way coupling forces and Darcy's Law to model solid-liquid interactions.
• Introduced a homogeneity metric to quantify mixing quality.

Main Results:

• Virtual experiments revealed that higher liquid content or viscosity slows the mixing process in high solid load mixtures.
• While solid particles achieve good mixing, liquid distribution remains non-uniform, particularly with low viscosity liquids.
• The simulation accurately predicted mixing behavior in benchmark cases.

Conclusions:

• The developed SPH-DEM model is a versatile tool for optimizing particle mixing processes.
• Findings can expedite the design and development of concrete materials and particulate composites.
• Understanding liquid distribution is key for achieving homogeneous final products.