Parallel adaptive simplical re-meshing for deforming domain CFD computations

Abstract

Deforming domains occur in many fields of computational fluid dynamics (CFD), such as interface tracking, simulation of pumps and engines, and fluid/structure interaction. The deformation of the domain presents a challenge to the integrity of the computational mesh; substantial motion of the domain boundaries requires vertex motion and changes in mesh connectivity. For cases of simple boundary motion or structured meshes, predetermined changes to the mesh structure can be sufficient. However, without a priori knowledge of how the domain will change, a more robust solution is required. The present work offers a parallelized solution for simplical meshes that is well-suited to extremely complex geometry. The mesh continuously evolves without user intervention or the use of target meshes. Varying length scales imposed by evolving boundary curvatures and narrow gaps are resolved with a fast length-scale algorithm. The set of algorithms are incorporated into an object-oriented code structure that permits broad application to a range of CFD problems. The robustness and versatility of the algorithm is demonstrated in several examples, representing motion of internal and external boundaries, where the boundary motion may or may not be known a priori.

Comparison of Surface Tension Models for the Volume of Fluid Method

“…Interface tracking methods, such as the moving mesh method, use a separate boundary-fitted moving mesh for each phase [22]. Although interface tracking methods are quite accurate, they are typically used to model bubble or droplets with mild-moderate deformations [22,23] but to handle complex interface deformations these methods require a global or local re-meshing [24]. Interface capturing methods use a fixed grid with functions to capture the interface such as the Volume Of Fluid method (VOF) [25], level-set [26] and diffuse interface methods [27].…”

Primal-mixed formulations for reaction–diffusion systems on deforming domains

“…in cardiac mechano-electrical-fluidic models), where mesh motion of the fluid domain may lead to highly distorted elements. A recent remedy, based on adaptive smoothing and remeshing is presented in [39].…”

A control volume finite element method for three‐dimensional three‐phase flows

“…There are some examples of the use of adaptive mesh refinement for structured meshes with VOF, hybrid‐level set/front‐tracking, and moment‐of‐fluid methods. Unstructured meshes are very attractive when dealing with complex geometries in engineering applications and there are examples of adaptive unstructured meshes with the interface tracking method, level set method, phase field method, and algebraic VOF method …”