A numerical model of translational and rotational momentum transfer of small on-spherical rigid particles in fluid dominated two-phase flows
(Third Party Funds Single)Term: 1. December 2014 - 31. January 2020
Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)The overarching goal of the proposed Mercator project is to establish a numerical model of translational and rotational momentum transfer of small non-spherical rigid particles in fluid dominated two-phase flows. Thereby the main aims are threefold:The first aim is to establish an accurate numerical model for particle-fluid interaction. It will in particular take into account the translational and rotational effects in the fluid flow field, and will put a special focus on the resulting particle rotational motion in terms of the accurate determination of its orientation and angular velocity. Here, the development of an advanced Lagrangian particle tracking algorithm for the tracking of non-spherical particles in a velocity-vorticity resolved fluid flow field and the development of a two-way coupling algorithmwithin a suited BEM framework, based on an advanced source distribution modelwithin the fluid phase, are planned.The second aim is to incorporate non-spherical particle force and torque models to capture the momentum transfer between particles and the fluid flow field. Here special attention will be paid to particle shapes in terms of generic ellipsoidal geometries. In the context of the envisioned rigid body modelling for the particles this will be accompanied by the development of a particle preprocessor in order to provide particle inertia properties.The third aim is to devise accelerated parallel numerical algorithms which will enable accurate and fast computations of the vortical part of the fluid flow field within the previously established BEM framework as well as the efficient solution of the set of DAEs related to the particle motion.The developed algorithms will be validated by comparison with independent computational results and will eventually be applied to the experimentally verified test case of sludge flocsedimentation.
Fracture Across Scales and Materials, Processes and Disciplines
(Third Party Funds Group – Sub project)Overall project: Fracture Across Scales and Materials, Processes and Disciplines
Term: 1. September 2017 - 31. July 2022
Funding source: EU - 8. Rahmenprogramm - Horizon 2020
Fracture across Scales: Integrating Mechanics, Materials Science, Mathematics, Chemistry, and Physics (FRASCAL)
(Third Party Funds Group – Overall project)Term: 1. January 2019 - 30. June 2023
Funding source: DFG / Graduiertenkolleg (GRK)
The RTG aims to improve understanding of fracture in brittle heterogeneous materials by developing simulation methods able to capture the multiscale nature of failure. With i) its rooting in different scientific disciplines, ii) its focus on the influence of heterogeneities on fracture at different length and time scales as well as iii) its integration of highly specialised approaches into a “holistic” concept, the RTG addresses a truly challenging cross-sectional topic in mechanics of materials. Although various simulation approaches describing fracture exist for particular types of materials and specific time and length scales, an integrated and overarching approach that is able to capture fracture processes in different – and in particular heterogeneous – materials at various length and time resolutions is still lacking. Thus, we propose an RTG consisting of interdisciplinary experts from mechanics, materials science, mathematics, chemistry, and physics that will develop the necessary methodology to investigate the mechanisms underlying brittle fracture and how they are influenced by heterogeneities in various materials. The insights obtained together with the methodological framework will allow tailoring and optimising materials against fracture. The RTG will cover a representative spectrum of brittle materials and their composites, together with granular and porous materials. We will study these at length and time scales relevant to science and engineering, ranging from sub-atomic via atomic and molecular over mesoscale to macroscopic dimensions. Our modelling approaches and simulation tools are based on concepts from quantum mechanics, molecular mechanics, mesoscopic approaches, and continuum mechanics. These will be integrated into an overall framework which will represent an important step towards a virtual laboratory eventually complementing and minimising extensive and expensive experimental testing of materials and components. Within the RTG, young researchers under the supervision of experienced PAs will perform cutting-edge research on challenging scientific aspects of fracture. The RTG will foster synergies in research and advanced education and is intended to become a key element in FAU‘s interdisciplinary research areas “New Materials and Processes” and “Modelling–Simulation–Optimisation”.
Numerical and experimental study of the deposition of micro-sized non-spherical solid particles in the nasal cavity
(FAU Funds)Term: since 1. January 2019
The deposition of atmospheric particulate matter, typically in the microrange and in sharp of non-spherical shape, in the nasal cavity gaining interestin recent years. It is important to investigate the deposition fraction ofparticles in the nasal cavity since these particles can be easily removed vianasal wash. The rest of particles will be travelled to the upper and lowerairways as well as the alveoli of the deep lung. Most of force and torquemodels for non-spherical particles are only valid for limited flowconditions. However, the flow field in the nasal cavity is rather complexand it is necessary to establish an accurate numerical model for tracking themotion of non-spherical particles moving in the nasal cavity in connection withexperimental validation. Moreover, many people have the problem of the deviatednasal septum and it is necessary to understand its influence on the pressuredrop and the deposition fraction of particles.