Martin Lautenschläger

• Wetted contacts play an important role in many fields. A prominent example in engineering is the lubricated contact between tool and workpiece in machining processes with cutting liquids. In such contacts, highly dynamic processes occur in the fluid at small length scales under extreme conditions regarding temperature, pressure, and shear. Experimental studies of these phenomena are generally not feasible. Thus, only little information on the actual processes in the contact zone is available. A tractable route for obtaining such information is molecular dynamics (MD) simulation. As input for these simulations, only a potential model that describes the interactions on the atomistic scale, is needed. On that basis also complex processes can be predicted. In the present work, a simple model potential was used, i.e. the Lennard-Jones truncated and shifted potential (LJTS), which was parameterized to describe the solids, the fluid, and their interactions. A novel method for determining fluid properties with non-equilibrium MD simulations was developed, which yields thermal, caloric and transport properties in a single simulation run. It can also be used for studying the influence of shear on these properties. With the new method, a comprehensive study of properties of the LJTS fluid was carried out. Furthermore, it was investigated how these fluid properties change near the solid-fluid interface and how these changes affect the conductive heat transfer between the solid and the fluid. Finally, a nanotribological process was studied, in which all these phenomena occur simultaneously.