http://hdl.handle.net/10900/83729 2026-05-12T15:48:33Z 2026-05-12T15:48:33Z Kley, Wilhelm Stoll, Moritz H.R. Picogna, Giovanni http://hdl.handle.net/10900/83817 2019-10-30T06:24:08Z 2018-08-14T00:00:00Z

Planets in turbulent Disks Kley, Wilhelm; Stoll, Moritz H.R.; Picogna, Giovanni Planets form in protoplanetary accretion disks around young protostars. These disks are driven by internal turbulence and the gas flow is in general not laminar but has stochastic components. For weakly ionized disks the turbulence can be generated purely hydrodynamically through the vertical shear instability (VSI). Planets, that are forming in such turbulent disks, experience random components in the torques acting on them, that will modify their migration behaviour. In this contribution we present results of our study of the impact that a turbulent disk has on an embedded planet. For that purpose we performed three-dimensional hydrodynamical simulations of a locally isothermal disk with embedded planets of various masses. For the lower mass planets (5 and 10 M ) we find that the inward migration rate can be faster than in the laminar case, while for the more massive planets (30 and 100 M ) the results agree well with the laminar results.

2018-08-14T00:00:00Z Renze, Peter http://hdl.handle.net/10900/83816 2019-10-30T06:23:58Z 2018-08-14T00:00:00Z

Numerical Simulation of Heat Transfer in Turbulent Pipe Flow with Structured Wall Surfaces Renze, Peter Innovative heat transfer technology is the key to the optimization of many processes in the power or process industry. Operational costs and usage of valuable resources can be reduced, if the heat transfer efficiency is increased and pressure loss is reduced. Therefore, the current work is focused on heat transfer enhancement at tubes with micro-structured walls with turbulent flow. In this kind of geometry modern optical measurement technology cannot be applied and the analysis of the turbulent transport is only possible with numerical flow simulations. A large-eddy turbulence model is applied to account for turbulence closures. First, the simulation setup is validated with data from the literature and then several micro-structured geometries are investigated. The simulations are computationally costly and depend on high performance computing (HPC). The open-source software library OpenFOAM® is applied to perform massively parallel simulations.

2018-08-14T00:00:00Z Janczyk, Michael Wiebelt, Bernd von Suchodoletz, Dirk http://hdl.handle.net/10900/83815 2019-10-30T06:30:56Z 2018-08-14T00:00:00Z

Virtualized Research Environments on the bwForCluster NEMO Janczyk, Michael; Wiebelt, Bernd; von Suchodoletz, Dirk The bwForCluster NEMO offers high performance computing resources to three quite different scientific communities (Elementary Particle Physics, Neuroscience and Microsystems Engineering) encompassing more than 200 individual researchers. To provide a broad range of software packages and deal with the individual requirements, the NEMO operators seek novel approaches to cluster operation [1]. Virtualized Research Environments (VREs) can help to both separate different software environments as well as the responsibilities for maintaining the software stack. Research groups become more independent from the base software environment defined by the cluster operators. Operating VREs brings advantages like scientific reproducibility, but may introduce caveats like lost cycles or the need for layered job scheduling. VREs might open advanced possibilities as e.g. job migration or checkpointing.

2018-08-14T00:00:00Z Baumann, Martin Heuveline, Vincent Mattes, Oliver Richling, Sabine Siebler, Sven http://hdl.handle.net/10900/83814 2019-10-30T06:23:49Z 2018-08-14T00:00:00Z

SDS@hd – Scientific Data Storage Baumann, Martin; Heuveline, Vincent; Mattes, Oliver; Richling, Sabine; Siebler, Sven SDS@hd (Scientific Data Storage) is a central storage service for hot large-scale scientific data that can be used by researchers from all universities in Baden-Württemberg. It offers fast and secure file system storage capabilities to individuals or groups, e.g. in the context of cooperative projects. Fast data accesses are possible even in case of a high number of small files. User authentication and authorization are implemented in terms of the federated identity management in Baden-Württemberg allowing researchers to use their existing ID of their home institution transparently for this service. Data protection requirements can be fulfilled by data encryption and secure data transfer protocols. The service is operated by the computing center of Heidelberg University.

2018-08-14T00:00:00Z