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OPEN FAU

Online publication system of Friedrich-Alexander-Universität Erlangen-Nürnberg

The online publication system OPEN FAU is the central publication platform for Open Access publishing for all members of Friedrich-Alexander-Universität. Qualified works from research and teaching may be published here free of charge, either as a primary or secondary publication. The full texts are permanently available worldwide and are findable and citable via catalogues and search engines.


To search for documents in OPEN FAU, please select "Search" (via the magnifying glass at the top right); this will provide you with various search options. If you want to publish a document, go to "Login" and "My Publications". Then drag you document into the field provided and enter the metadata. In just a few steps, you can submit your document. Please note our guidelines, the publication contract and FAQs.

 

Recent Submissions

Master thesis
Open Access
Pattern formation in a horizontally vibrated granular submonolayer
Proceedings of the Institute for Multiscale Simulation (2012-01-26) Krengel, Dominik; Pöschel, Thorsten
In 1995, Strassburger et al [27] carried out an experiment in which they shook a sub-monolayer of particles horizontally. Their investigations revealed that particles arranged themselves in stripes under the influence of the shaking. To describe this behavior, they developed a simple cellular automaton model: during an impact, all particles jump simultaneously in the direction of impact until they come to rest on a left and a right neighbor. However, the jumping could never be observed experimentally, suggesting that the streaking has a different cause. The aim of this work is to identify the key mechanism for streak formation in a horizontally shaken submonolayer of particles. For this purpose, the experiment of Strassburger et al. is repeated to confirm the effect. Based on the experiment, a force-based multiparticle simulation is performed to specifically investigate the system. It is shown that although particles can jump during the simulation, this is not essential for their streak formation. Friction between particles can be identified as the basis for streak formation, which means that particles in contact can no longer roll freely and move together with the bottom of the shaking container. Furthermore, it is found that streaking only occurs at higher excitation amplitudes and lower excitation frequencies. Other combinations lead to the particles in the system either not being supplied with enough energy to form streaks, or receiving too much energy and assuming a gas-like state. A comparison between the experiment and simulation shows that the non-round particles used in the experiment, which can only roll to a limited extent, lead to deformed stripes within which the particles are quasi-stationary. In the simulation, on the other hand, perfectly round spheres were used and strips with low deformation were generated, within which the particles exhibit high mobility. During the preparation of the simulation, collisions of three-dimensional particles were analyzed. It was found that the normal restitution coefficient can assume negative values. This effect was already known for high-speed impacts of nanoparticles [52]. However, it can be shown that this effect is a general phenomenon resulting from the geometry of the impact. Negative restitution coefficients can be observed for all types of collisions that are determined by finite interaction forces.
Master thesis
Open Access
Homogenization of Fluid Driven Granular Pipe Flow
Proceedings of the Institute for Multiscale Simulation (2021-09-01) Al-Ani, Abeer; Müller, Patric
The clogging of a dense stream of particles occurs vastly in both natural and industrial fields. Since most of jamming phenomena lead to negative effects on the flow stream, studying and preventing jamming is of critical importance. Following a previous work of [2], which investigated the clogging of particle gravity-driven flows in vacuum and affirmed the possibility of attaining steady material transport by adding a helical structure to the inner wall of the pipe without the need for energy input from any external source. In the current study, we reproduced and extended this method by using ANSYS Fluent and investigating the effect of air presence on the gravitationally driven pipe flow. We employed the Macroscopic Particle Model (MPM) for particles modelling and Computational Fluid Dynamics (CFD) for the two-way coupling of air-particle interaction. Results showed that flow in both vacuum and air is inhomogeneous and characterized by intermittent flow and density waves. We investigated the effect of the helical texture on particle flow by comparing gravity-driven flow with and without helix structure. We found that the helix texture promotes more homogenous particle flow along the pipe in vacuum, whereas the helix in the presence of air could not completely collapse the clusters, as there are still small groups of colloidal particles in some regions. Furthermore, we examined fluid-driven jamming and found that the complex effects of initial solid concentration and fluid velocity have a direct impact on the occurrence of jamming.
Master thesis
Open Access
The Dzhanibekov-Effect - an intuitive theoretical and practical approach to understand the rotation of rigid bodies about their intermediate axis
Proceedings of the Institute for Multiscale Simulation (2023-06-16) Aseervatham, Bijohn Chandrew; Buchele, Felix
Bachelor thesis
Open Access
Aufbau und Erprobung eines Versuchsstands zur berührungslosen Handhabung flüssiger und fester Objekte mit Ultraschall
Proceedings of the Institute for Multiscale Simulation (2018-10-04) Massa, Jonas; Sack, Achim
Bachelor thesis
Open Access
X-ray characterization of root growth in granular media
Proceedings of the Institute for Multiscale Simulation (2018-09-21) Elhaus, Nora; Schröter, Matthias