Regularized modelling of phoretic particles in reactive suspensions.*

Reactive suspensions consist of many self-propelled particles in a fluid that catalyze chemical reactions on their surface. This activity generates chemical gradients in the system which, in turn, create a phoretic slip velocity along the particle surface and drives the particles' motion. Finding the particles' velocities requires solving first the Laplace problem for the solute concentration with prescribed chemical fluxes, and then the Stokes problem for the fluid motion forced by the phoretic slip velocities in response to the concentration distribution.
To model these coupled diffusio-phoretic effects and hydrodynamics interactions, we propose a generalization of the classical Force Coupling Method (FCM) to treat both problems in an integrated framework. The new generalised FCM framework will be introduced, focusing specifically on the novel treatment of the diffusion problem and its coupling to the hydrodynamics. Its validation and comparison with other analytical and numerical methods will be presented on several canonical yet generic two-particle interaction problems.