Lattice Boltzmann for particle dissolution and growth simulations

Presented by Rohan Vernekar - University of Edinburgh, UK

Abstract: Particles at the small scales such as silica nano and micro particles have a wide rage of potential future applications from drug delivery to surface coatings. Control over the morphology, size distribution, porosity and dispersity of such particles is crucial for realizing their intended industrial applications. The physics and chemistry of growth of such particles under suspension flow conditions is not well understood, and is often a complex outcome of various effects and process time scales (e.g. advection, diffusion, reaction and deposition rates). Therefore predictive numerical simulation tools are crucial in order to realize industrial scale-up of particle growth processes.

I use a novel lattice Boltzmann (LB) algorithm that models growth of particles under particle-resolved flow conditions via chemical species deposition. This algorithm combines fluid LB for incompressible hydrodynamics, advection-diffusion LB for chemical species transport, resolved suspended particle dynamics through interface tracking and a mesoscale adsorption bundary condition for particle growth. The code can also be used for particle dissolution under flow, simply by reversing the surface reaction boundary condition at particle-fluid interface.

The algorithm is versatile enough to address a wide range of coupled problems such as particle growth under sheared suspension conditions, particle sedimentation coupled to reactive growth as well as particle dissolution under flow stirring. I shall present a selection of these problems demonstrating the capabilities of the solver, which enables the study of flow effects on particle growth/dissolution, morphology and size distribution of suspensions.