Fluid Flows at the Nano Scale: from Molecular Dynamics to Hydrodynamics

How fluid flows behave at the nano scale is critical to some innovative engineering applications proposed for nanotechnology, such as using nano fibres for desalination, and waste water contaminant control and treatment. However, important aspects of these highly-confined, small-scale flows are not understood. This is because the conventional Navier-Stokes equations with no-slip boundary conditions often do not apply (as the flow is far from equilibrium) or the physical conditions are too complex and system-specific to make accurate a priori assumptions or simplifications. Our vision in this project is, therefore, to provide new understanding of fluid dynamics under these extreme conditions --- beyond that of current models. To do this we will create a unique numerical tool to investigate engineering flows (both gas and liquid) at the smallest scales.Drawing on our distinctive expertise in the UK of modelling non-equilibrium micro scale gas flows, we will develop a new hybrid model that couples a molecular dynamics (MD) description of the flow in arbitrary geometries to a hydrodynamic description. To date, hybrid/MD techniques have remained in the domain of chemistry and physics but our focus will be on problems in engineering science, including modelling high-throughput selective filtration, and exploring how we can manipulate the hydrophobicity, heat transfer, chemical and other fluid/surface properties to produce 'smart' surfaces and structures.