Project Details
Projekt
Modelling of spreading, imbibition and evaporation of liquids on structured or porous deformable substrates
Subject Area
Chemical and Thermal Process Engineering
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 422792679
Spreading, imbibition and evaporation of liquids on deformable surfaces with roughness, topography or with porous coatings is important for numerous industrial applications. These phenomena are multiscale and cannot be described using the macroscopic approach, which ignores the effect of intermolecular interactions. The project is aimed at development of models for spreading, imbibition and evaporation of liquids on structured or porous deformable substrates and takes into account the effects of the surface forces, described employing the disjoining pressure concept. In the first funding period, the static and dynamic wetting of the droplets with height comparable with the range of surface force action has been studied using a thin film theory-based numerical model. It has been found that if the nanodrop spreads over a deformable solid, the wetting ridge can exhibit a non-monotonic dynamics. The evolution of the ridge shape depends on the parameters of the disjoining pressure isotherm. The capillary-driven flow in corner geometries has been studied. The surface forces have been shown to define the maximal length of rivulets in open wedge channels. Remarkably, the steady rivulets cannot be predicted when the surface forces are ignored. In the next funding period the developed models will be extended and used to describe the liquid spreading, imibibition and evaporation in nanopores, on deformable surfaces with topography and inhomogeneous distribution of mechanical properties, as well as in systems containing thin flexible sheets, lamellas and fibers. The results of these studies will allow elucidating the key phenomena governing imbibition on a scale of the whole porous structure. Homogenization techniques for computation of effective transport coefficients will be applied on the basis of this knowledge. These coefficients will be used for macroscopic-scale simulation of imbibition and evaporation on structured or porous deformable substrates, which are relevant to natural phenomena and technological applications. The results of simulations will be validated by comparison with experimental data.
DFG Programme
Priority Programmes
