The capture of small particles at the interface of large deformable drops and the subsequent evolution of particle surface distribution in turbulent flow are investigated. Direct numerical simulation of turbulence, phase field modeling of the drop interface dynamics and Lagrangian particle tracking are used. Realistic distribution of particles is ensured by excluded-volume interactions, i.e. by enforcing particle collisions. Particles are initially dispersed in the carrier flow and are driven in time towards the surface of the drops by jet-like turbulent fluid motions. Once captured by the interfacial forces, particles disperse on the surface. Excluded-volume interactions bring particles into longterm trapping regions of vanishing surface velocity divergence, where high-concentration particle clusters are formed. These regions correlate well with portions of the interface characterized by higher-than-mean curvature, indicating that modifications of the surface tension induced by the presence of tiny particles will be stronger in the highly-convex regions of the interface.
TURBULENCE-CONTROLLED EVOLUTION OF PARTICLE PATTERNS ON THE INTERFACE OF LARGE DEFORMABLE DROPS IN CHANNEL FLOW
Marchioli C.
;Hajisharifi A.;Soldati A.
2024-01-01
Abstract
The capture of small particles at the interface of large deformable drops and the subsequent evolution of particle surface distribution in turbulent flow are investigated. Direct numerical simulation of turbulence, phase field modeling of the drop interface dynamics and Lagrangian particle tracking are used. Realistic distribution of particles is ensured by excluded-volume interactions, i.e. by enforcing particle collisions. Particles are initially dispersed in the carrier flow and are driven in time towards the surface of the drops by jet-like turbulent fluid motions. Once captured by the interfacial forces, particles disperse on the surface. Excluded-volume interactions bring particles into longterm trapping regions of vanishing surface velocity divergence, where high-concentration particle clusters are formed. These regions correlate well with portions of the interface characterized by higher-than-mean curvature, indicating that modifications of the surface tension induced by the presence of tiny particles will be stronger in the highly-convex regions of the interface.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
