Stationary regimes of axisymmetric thermal wake interaction of two buoyant drops at low Reynolds and high Peclet number

• Published in: Physics of fluids (1994) 2006-07, Vol.18 (7)
• Main Authors: Frolovskaya, O., Nir, A., Lavrenteva, O. M.
• Format: Article
• Language: English
• ISSN: 1070-6631; 1089-7666
• DOI: 10.1063/1.2219765

Axisymmetric motion of a leading fluid drop and a trailing gas bubble (or thermally nonconducting drop) in a viscous fluid under the combined effect of gravity and thermocapillarity is considered under the assumption of negligible inertia effects and of nondeformable interfaces. The ambient fluid far from the inclusions is isothermal and the temperature of the leading particle differs from that of the continuous medium. At large Peclet number, thermal boundary layers are present along the fluid-liquid and the gas-liquid interfaces, and thermal wakes are formed downstream from the particles. The interaction of the thermal wake, shed from the leading inclusion, with the thermal boundary layer on the surface of the trailing one causes a nonuniform temperature distribution on the surface of the latter. The induced Marangoni flow results in the change of the flow pattern, the velocity of both particles, and the equilibrium separation distance. In the present paper, the influence of the Marangoni effect on the drag force and the rate of heat transfer from the drops translating at given velocity is studied as well as on the equilibrium velocities and separation distance of the drops freely migrating under the action of gravity. The analysis considers particles at arbitrary separation distance and takes full account of thermal and hydrodynamic interactions.