Computational algorithms for tracking dynamic fluid–structure interfaces in embedded boundary methods

Abstract

SUMMARY A robust, accurate, and computationally efficient interface tracking algorithm is a key component of an embedded computational framework for the solution of fluid–structure interaction problems with complex and deformable geometries. To a large extent, the design of such an algorithm has focused on the case of a closed embedded interface and a Cartesian computational fluid dynamics grid. Here, two robust and efficient interface tracking computational algorithms capable of operating on structured as well as unstructured three‐dimensional computational fluid dynamics grids are presented. The first one is based on a projection approach, whereas the second one is based on a collision approach. The first algorithm is faster. However, it is restricted to closed interfaces and resolved enclosed volumes. The second algorithm is therefore slower. However, it can handle open shell surfaces and underresolved enclosed volumes. Both computational algorithms exploit the bounding box hierarchy technique and its parallel distributed implementation to efficiently store and retrieve the elements of the discretized embedded interface. They are illustrated, and their respective performances are assessed and contrasted, with the solution of three‐dimensional, nonlinear, dynamic fluid–structure interaction problems pertaining to aeroelastic and underwater implosion applications. Copyright © 2012 John Wiley & Sons, Ltd.

Parallel adaptive fluid–structure interaction simulation of explosions impacting on building structures

“…While the utilization of an Eulerian fluid mesh with embedded boundary capability is nowadays frequently employed for FSI simulations with large structural motions, cf. (Wang et al, 2012;Zhao et al, 2008;Puso et al, 2012), we enhance its accuracy independent of a particular scheme by combining it with dynamic adaptation of the fluid mesh. Unique to our approach, we additionally employ recursive fluid time step refinement and the specially extended FSI coupling algorithms have been described.…”

“…Banks et al (2012)), for which the discretizations both in fluid and solid are usually time-explicit and therefore computationally comparably inexpensive. On the other hand, major geometric complexities, such as large structural deformations (Wang et al, 2012), fracture and even fragmentation, might have to be considered. An approach to this problem is to employ an immersed or embedded boundary method in the fluid solver (Mittal and Iaccarino, 2005), in which moving solid structures slide through a fixed Eulerian fluid background mesh.…”

FIVER: A finite volume method based on exact two-phase Riemann problems and sparse grids for multi-material flows with large density jumps

“…This framework is suitable not only for multi-fluid applications, but also for multi-material flow problems involving static or dynamic, rigid or flexible solid domains. In particular, it is usually preferred over the Lagrangian and ALE frameworks [21][22][23] for the solution of high-speed compressible fluid-structure and multi-fluid-structure interaction problems characterized by large structural deformations [24][25][26] and/or topological changes such as those associated with crack propagation.…”

A flexible level-set approach for tracking multiple interacting interfaces in embedded boundary methods

“…The flow solution in the vicinity of the embedded boundaries is addressed in a multitude of individual methods as stated above. At the same time, the description of the interface itself, the tracking of its motion, and the reconstruction of relevant instantaneous information about the interface position on the background mesh is the other essential ingredient for the success of an embedded boundary method [20]. This aspect will be discussed in this paper with a focus on multiple three-dimensional complex moving interfaces embedded in a hierarchically refined Cartesian grid.…”

“…This aspect will be discussed in this paper with a focus on multiple three-dimensional complex moving interfaces embedded in a hierarchically refined Cartesian grid. Unlike Wang et al [20], we will only consider closed surfaces, i.e., no bodies of infinite thickness. This part of the embedded boundary problem can be treated on a rather general basis, so the method presented in this paper can be applied independently of the approach that is chosen to incorporate the influence of the boundary on the fluid phase.…”