ZURUECK HOCH VOR INHALT SUCHEN

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Proposing Institution

Lehrstuhl für Thermodynamik (LTD), Technische Universität Kaiserslautern
Project Manager

Dr.-Ing. Martin Thomas Horsch
Erwin-Schrödinger-Str. 44
67663 Kaiserslautern
Abstract
For nanosystems, thermodynamic and kinetic laws that hold for macroscopic systems may break down due to the predominance of surface over bulk effects as well as the interference between continuous variations of thermodynamic properties and the discrete structure of matter at the mole­cular level. Molecular modelling is a reliable method for describing and predicting thermodynamic properties that is well suitable for investigating phenomena on small length and time scales. The present project examines interfacial properties of fluids, their contact with solid materials (wet­ting and adsorption), interfacial fluctuations and finite-size effects, linear transport coefficients in the bulk and at interfaces and surfaces as well as transport processes near and far from equilibrium. These phenomena are investigated by massively-parallel molecular dynamics simulation, based on quantitatively re­liable classical-mechanical force fields. The simulation results are combined to obtain an understan­ding of the complex processes undergone by cutting liquids during machining, in particular in the region of contact between the tool and the work piece. By non-equilibrium molecular dynamics (NEMD), trans­port processes can be studied in a well-defined way. Furthermore, line­ar transport coefficients are accessible by equilibrium molecular dynamics simulation (EMD). With efficiently parallelized MD codes, scale-bridging simulation approaches for systems containing up to a trillion molecules have become feasible in recent years. Here, the program ls1 mardyn is used, which has already been used on SuperMUC for simulating four trillion molecules.The main objective of the present project consists in quantifying the size dependence of interfacial and transport properties on the nano- and microscale. Since the number of molecules scales with the third power of the characteristic length scale, this requires a scale-bridging simulation approach. At the upper end of the accessible range of lenth and time scales, an efficient exploitation of the available tier-0 HPC resources becomes crucial. Thereby, petascale molecu­lar dynamics simulations containing up to ten billion molecules will be conducted, and further large scale production runs will be carried out for up to a hundred million molecules. Since larger sys­tems also require a longer relaxation time to reach equilibrium, fast equilibration techniques will be explored and employed for petascale simulations, and long simulations will be carried out for the large scale systems, corresponding to a simulation time of the order of 100 ns.

Impressum, Conny Wendler