Eine Immersed-Boundary-Methode zur Simulation von Strömungen in komplexen und bewegten Geometrien

Autor*innen

• Eike Alexander Hylla

Parameter

• Lehrbücher
• Universitätslehrbücher

Mehr zum Buch

The Immersed Boundary Method (IBM) is a numerical approach in computational fluid dynamics ideal for complex and dynamic geometries. This method immerses the geometry into a computational grid, solving the Navier-Stokes equations while satisfying boundary conditions at the intersections of the surface discretization and grid cells. This work details the implementation, validation, and application of an IBM approach based on an existing finite-volume flow solver, emphasizing the use of a Ghost-Cell approach for boundary conditions. It also introduces mechanisms for rapid detection of cell intersections, grid adaptation techniques, and numerical algorithms for managing the resulting equation systems. Additionally, the methodology is enhanced to address Fluid-Structure Interaction (FSI) by implementing a Finite-Element based structural solver. The CFD and FEM solvers are loosely coupled to exchange fluid forces and the geometry of the elastic body. The methods are applied to two areas suitable for IBM solvers: first, investigating airflow through various central airway geometries, revealing smooth secondary flow structures and Dean vortices in a simple lung model. In the more complex case of a dynamic tracheobronchial tree, surface motion during respiration creates asymmetrical counter-rotating vortices. Secondly, FSI is analyzed with a quasi-steady flow past an elastic cylinder shell, where after a few coupling iterations, the d

• Sprache: Deutsch
• Erscheinungsdatum: 2013