Colloquium PD Dr.-Ing. Tatiana Gambaryan-Roisman
Multiscale modelling of near-wall multiphase flows with heat transfer and phase change: from analytical models to direct numerical simulations
When: Friday 11 October 2013
Where: Filmzaal, Zwarte Doos, TU/e campus
In this presentation an overview of modeling methods for multiphase flows employed in my group will be given. The multiphase systems under consideration include falling films and rivulets on structured surfaces, thermocapillarity-driven liquid layers, evaporating droplets and coalescing partially melted metal particles. The models take into account the flow dynamics and stability, heat transfer, evaporation, melting, intermolecular forces and Marangoni effect. The modeling approaches include long-wave theory, stability analysis, solution of Graetz-Nusselt problem, Finite Elements Method, Boundary Element Method and Volume-of-Fluid method. Modular multiscale approach is employed to account for the complex nano- and microscale heat and mass transport processes in the vicinity of evaporating contact line, which in many cases govern the overall heat and mass transport at a macroscale.
The near-wall multiphase flows can be effectively controlled by the modification of the wall, including the wall topography, chemical patterning and using wall material with gradient of physical properties. The mechanisms of influence of wall modification on hydrodynamics and transport processes in liquid films, rivulets and drops are discussed. The theoretical and numerical models are validated by comparison with experiments.