Phoretic motion of soft vesicles and droplets: an XFEM/particle-based numerical solution

Abstract

When immersed in solution, surface-active particles interact with solute molecules and migrate along gradients of solute concentration. Depending on the conditions, this phenomenon could arise from either diffusiophoresis or the Marangoni effect, both of which involve strong interactions between the fluid and the particle surface. We introduce here a numerical approach that can accurately capture these interactions, and thus provide an efficient tool to understand and characterize the phoresis of soft particles. The model is based on a combination of the extended finite element—that enable the consideration of various discontinuities across the particle surface—and the particle-based moving interface method—that is used to measure and update the interface deformation in time. In addition to validating the approach with analytical solutions, the model is used to study the motion of deformable vesicles in solutions with spatial variations in both solute concentration and temperature.

Mechanical instability and percolation of deformable particles through porous networks

“…The challenge in answering this question is the existence of two disparate length-scales: the macroscale (or Darcy scale) and microscale (or pore scale), both of which play distinct, but yet critical roles in particle transport. At the pore scale, models have been developed to elucidate the relation between particle mechanics [13][14][15][16][17] and motion [18][19][20][21][22] for different types of particles and flow conditions. Such relations typically characterize the entry of particle with various size, shape, structure, and adhesion properties [23][24][25][26][27][28][29] in narrow constrictions such as the nozzle of micropipettes.…”

Computational modeling of the large deformation and flow of viscoelastic polymers

“…To track the evolution of the interface Γ , we use the particle-based moving interface method (PMIM) [25,41,59], where the interface is represented by particles whose spatial distribution remains quasi-uniform over time. To avoid repetition, we here summarize the main steps of the method; interested readers can find additional details in “Appendix 5”.…”

Simulating squirmers with volumetric solvers

“…Restricting thus to precedents for the type-I case, Aguillon et al [1] consider the squirmer problem discretized on a fixed mesh through the fictitious domain method [24]. Shen and Vernerey [64], in their method for surface-active vesicles, also turn to a fixed-mesh technique by means of extended finite elements. Besides the generality of the boundary conditions, this contribution differs from these precedents in that the mesh conforms to the squirmers' boundaries in an arbitrary Lagrangian-Eulerian (ALE) manner [2,15,27,61].…”