Lattice Boltzmann Simulation of Flow around moving Particles

Ich versichere, dass ich die Arbeit ohne fremde Hilfe und ohne Benutzung anderer als der angegebenen Quellen angefer-tigt habe und dass die Arbeit in gleicher oder ähnlicher Form noch keiner anderen Prüfungsbehörde vorgelegen hat und von dieser als Teil einer Prüfungsleistung angenommen wurde. Alle Ausführungen, die wörtlich oder sinngemäß über-nommen wurden, sind als solche gekennzeichnet. Abstract Abstract In the field of particle technology, the characterization of nano-particles and their behavior in a flow has become a major topic for industrial applications. The force interaction between the fluid and the nano-particles is one of most important research areas. Especially the forces, which occur between several sintered particles, are of interest. These forces are responsible for structural changes and are still only basically understood due to the limited capabilities of physical measurements. In contrast to the classical physical nano-particle characterization, the numerical simulation has the ability to gain insight into the structural properties of nano-particles. This thesis presents a way to simulate the nano-particle behavior in a flow by coupling a computational fluid dynamics solver for the simulation of the fluid to a rigid body physics engine for the simulation of the particle movements. For the fluid simulation, the Lattice Boltzmann Method will be used, which has gained increasing popularity in the last decade. Compared to the classic Navier-Stokes approach, it offers a simpler, yet stable implementation for the calculation of the macroscopic fluid properties and offers a better adaptability for parallelization efforts. Due to the kinematic origin of the Lattice Boltzmann Method, it is especially suitable for the coupling to a rigid body physics engine. By extending the basic fluid simulation for the treatment of curved particle surfaces and by a fluid particle force interaction method, the fluid forces acting on the nano-particles can be calculated. With this force interaction between the fluid and the particles and the use of the rigid body physics engine, the movement and collision behavior of nano-particles in a flow can be simulated. Additionally, this coupled simulation system is able to simulate the internal particle forces in the connections between sintered particles, which could break due to the forces of a shear flow. Therefore a prediction of possible break-ups becomes possible. For the validation of the nano-particle simulation several analytical calculations are compared to simulation results. Abstract I