EU Regional School - Phillpot Seminar
Prof. Dr. Simon R. Phillpot - Classical Interatomic Potentials for Moilecular Dynamics Simulations: Recent Advances and Challenges
The remarkable increasing in computing power and rapid advances in simulation methodologies over the last three decades have led to computer simulation becoming a third approach, complementary to experiment and theory, to exploring materials systems. Molecular Dynamics (MD) simulation is the dominant method for the simulation of complex microstructures and dynamical effects with atomic-scale resolution.
This presentation offers a brief introduction to MD methods and then focuses in on the interatomic potential. The interatomic potential is a mathematical description of the interactions among the atoms and ions in the system and thus defines the material being simulated. To provide a foundation, we review some of the standard interatomic potentials for metals, ceramics and covalently-bonded materials. We then focus on recent developments in the area of reactive potentials that can describe materials systems in which metal, ionic and covalent bonding coexist. Specifically, we present details of the Charge Optimized Many Body (COMB) potential formalism and its applications to a number of materials systems. Finally, we address the issue of the development of interatomic potentials. Currently, this is a black art: it can take a skilled researcher many months to develop a potential for a single system. We present a new paradigm for the rational design of interatomic potentials that will greatly accelerate their development and offer a number of other advantages over standard approaches.
EU Regional School - Modersitzki Seminar
Prof. Dr. Jan Modersitzki - Mathematical Models for Correspondence Problems in Medical Imaging
I³MS - Auricchio Seminar
Prof. Dr. Ferdinando Auricchio - 3D Printing: Some Experimental and Numerical Investigations
Additive manufacturing (AM) has recently emerged as a disruptive technology able to revolutionize design and production paradigms, paving the way for new and futuristic applications. However, the growing experience that industries, consumers, and research institutions are maturing on AM clearly indicates the need for new and effective design approaches, adapted and optimized for AM technologies. Computational modeling, in particular, may play a key role for a better comprehension of materials and product performances, as a basis for the development of high performance components, more effective production systems, and innovative applications. However, the multi-physic (from mechanical to thermal phenomena) and multi-scale (from local phase-changes and microstructural aspects to the performance of the entire 3d printed component) characteristics of the AM process represent significant challenges. The presentation will try to address some initial attempts in the modeling of additive manufacturing processes as well as some initial experimental campaigns on specific printing technologies.
I³MS - McDoniel Seminar
Dr. William McDoniel - DSMC Simulation of Io's Plumes and Atmosphere
AICES Graduate School, RWTH University Aachen
Jupiter's moon Io is the most volcanically active body in the solar system and its giant SO2 plumes rise hundreds of kilometers above its rarefied atmosphere. These plumes leave huge, asymmetric deposition rings behind on Io's surface and are the ultimate source of surface frost on Io and of material for Jupiter's plasma torus. The direct simulation Monte Carlo method is used to model one of Io's night-side plumes from the surface of the lava lake from which it erupts, up to its umbrella-shaped canopy shock, and back down to Io's surface where it creates an asymmetric deposition ring. Simulations of plumes being bombarded by ions show how the plume/plasma interaction depends on the location of the plume on Io and how plumes play an important role in supplying Jupiter's plasma torus. Simulations of plumes over an entire Io day show how plume material becomes suspended in and displaces the sublimation atmosphere such that models of the plume/atmosphere interaction which assume that the plume and sublimation components of the atmosphere are independent can yield poor estimates for the total volcanic mass flux, surface thermal inertia, and other parameters.
I³MS - Klar Seminar
Prof. Dr. Axel Klar - Mean Field Approaches to Interacting Particles and Fiber Dynamics
The talk will present an application-oriented introduction to mean-field approximations of interacting physical systems. We investigate microscopic particle systems and their mean-field approximations as well as related hydrodynamic and scalar macroscopic models. Numerical methods for these equations based on mesh-free particle methods for fluid-dynamic equations are discussed, as well as asymptotic preserving approaches for the transition between the different equations. Finally, applications to non-woven textile production, granular flow and crowd dynamics are presented.