  (Abbreviated) In this paper we report on the development of a multiscale
method for simulating complex liquid-liquid systems such as water in contact
with oil containing asphaltenes. We consider simulations where water drops
covered with asphaltenes are deflated, and reproduce the crumpling observed in
experiments. The method on the nanoscale is based on using coarse-grained
molecular dynamics simulations of the interface, with an accurate model for the
asphaltene molecules. This enables the calculation of interfacial properties.
These properties are then used in the macroscale simulation, which is performed
with a two-phase incompressible flow solver using a novel hybrid
level-set/ghost-fluid/immersed-boundary method for taking the complex interface
behaviour into account. We validate both the nano- and macroscale methods.
Results are presented from nano- and macroscale simulations which showcase some
of the interesting behaviour caused by asphaltenes affecting the interface. The
molecular simulations presented here are the first in the literature to obtain
the correct interfacial orientation of asphaltenes. Results from the macroscale
simulations present a new physical explanation of the crumpled drop phenomenon,
while highlighting shortcomings in previous hypotheses.
