Cut cell strategy for 3-D blast waves numerical simulations

Abstract

This paper presents the results obtained by a generalized cut cells strategy on 3-D blast waves problems. The mesh is cartesian except when it is intersected by the surface of the solids inserted in the computational domain. The improvement, relatively to a classical cut-cells method, is the treatment of the cut which preserves the real geometry of the surface instead of approximating it by a plane. This approach avoids a loss of precision of the numerical scheme at the boundaries and allows future extension to higher order schemes (> 2). Moreover it is useful for any kind of geometry with a high efficiency in computation time. The drawback is the complexity of the geometrical problems which can rise because of the diversity of situations in the treatment of the cuts. The performance of the approach is tested on a few examples allowing comparisons with experiments or other techniques and physical discussions.

Effective transport properties of the porous electrodes in solid oxide fuel cells

“…These correspond to a cathode microstructure of LSM and YSZ powders [43] and an anode microstructure of Ni and YSZ powders [59]. Earlier work [43,59] was confined to quantification of the geometric properties of the electrodes. The present study extends previous work in terms of obtaining results for the effective transport properties of the cathode and anode reconstructions.…”

“…The measurable parameters such as the particle size distributions of ceramic powders, the solid volume fraction of lanthanum strontium manganite (LSM) and yttria-stabilized zirconia (YSZ) phases, and the porosity are used as the input parameters to reconstruct the microstructure. Second, three different types of computational grids are considered: Cartesian, non-conforming octree [57,58], and unstructured body-fitted/cut-cell [59][60][61]. In each case, the grid passes through all three distinct phases (pore, electron, and ion).…”

Estudo do Galgamento de Estruturas Marítimas utilizando um Modelo Numérico baseado na Teoria da Onda em Condições de Água pouco Profunda

“…A similar approach can be used in three space dimensions [34,33] but the body surface is defined using a conformal surface triangulation. In this surface triangulation has only to be of sufficient quality to give an accurate body representation as it is not used directly to discretise the flow solution, representations obtained from CAD systems are thus normally appropriate.…”

“…In the original implementation 16 cut cell types [31,32] were used to compute this geometric information. In the three dimensional solver vector algebra has been used [33,34]. The fluid area of the cell sides can be calculated based on the intersection points at the cell edges.…”

“…This conceptually simple approach "cuts" solid bodies out of a background Cartesian mesh. Although originally developed for potential flow, the method has been successfully applied to the Euler equations in two [30,31,32] and three [33,34] space dimensions, to the Shallow Water Equations (SWE) [35] with static and moving boundaries and has been extended to deal with low speed incompressible flows [36,37,38] and flows involving moving material interfaces [39,40,41].…”