Hydrodynamic Interaction between Spheres Coated with Deformable Thin Liquid Films

Emulsions stability, from dilute to dense emulsions — Role of drops deformation

“…A comparison, although interesting, with deformable thin liquid films coated on solid spheres, where hydrodynamic interactions are present, must be analyzed very carefully. The general formulation performed by Yang et al [273] solved numerically shows that as the two spheres approach each other, the films begin to flatten and eventually to form negative curvature (or broad dimple) at the forehead areas in which high lubrication pressure is formed. The dimple formation occurs earlier as the capillary number increases.…”

Collisions of liquid coated solid spherical particles in a viscous fluid

“…(18) in [21]. Here, the constant resulting from the integration with respect to r has been eliminated to ensure regularity of q 1 , q 2 and q 3 at r = 0.…”

“…We extend the work of Yang et al [21] by solving the full dynamical problem in time as well as in space (not adopting a quasi-steady assumption), and by presenting results for particles of different radius and particles that are partially coated. Following the corresponding analysis of uncoated particles [2], one particle is considered to be at a fixed location during the collision.…”

“…In this way, the instantaneous velocity of approach and center-to-center distance of separation (and the fluid properties) determine the distributions of the thickness of the coating layers and the pressure; the Stokes number drops out of the analysis. Although their analysis is for particles that are not of equal size, Yang et al [21] restricted their presentation of results to equal-size particles. Their solutions for the steady film shapes revealed qualitatively different behaviour depending on the magnitude of the capillary number.…”

“…Information on these issues is essential input in large-scale simulations of, e.g., granulation [18][19][20]. The main study in the literature of approaching pre-coated spheres was carried out by Yang et al [21]. They used lubrication theory to derive equations for the interfacial shapes; intermolecular forces were neglected.…”