Finite-Size Coherent Structures in Thermocapillary Liquid Bridges

Abstract

When small particles are suspended in a three-dimensional steady incompressible flow, Lagrangian coherent particle structures can be created by dissipative mechanisms which rely either on inertia, buoyancy or particle–boundary interactions. The dissipative effect particles experience when moving close to a wall or a free surface can lead to a particular rapid attraction of the particles to periodic, quasi-periodic or strange orbits. The particle–boundary interaction dominates the accumulation of particles in thermocapillary liquid bridges of millimetric size if the particles are small, giving rise to finite-size c oherent s tructures, d epending o n t he t opological t emplate o f t he u nderlying i ncompressible fl ow. The achievements obtained in understanding finite-size coherent structures in liquid bridges are reviewed, commenting the theoretical, experimental and numerical developments over the last two decades. Moreover, open questions and perspectives of the research on finite-size Lagrangian coherent structures are discussed.