His current work is in numerical multiphase fluid mechanics and how small-scale fluid phenomena drive and modulate environmental processes, especially in problems of air-sea interaction and coastal transport. Specific topics include: deformation and breakup of droplets and bubbles, especially in a turbulent environment; splashing of droplets, jets and bulk fluids; small-scale dynamics of breaking waves in deep- and shallow-water environments; wave modelling at small to intermediate scales; first-principles developments of parametrisations in ocean waves and associated processes.
More broadly, Wouter has also done extensive numerical and theoretical work on shocks and interfacial stability problems (particularly Richtmyer-Meshkov and Rayleigh-Taylor) in gas-dynamic and magnetohydrodynamic flows, motivated by applications in nuclear fusion and aerospace engineering.