Parallel Unstructured Mesh Adaptation Based on Iterative Remeshing and Repartitioning

Abstract

We present a parallel unstructured mesh adaptation algorithm based on iterative remeshing and mesh repartitioning. The algorithm rests on a two-level parallelization scheme allowing to tweak the mesh group size for remeshing, and on a mesh repartitioning scheme based on interface displacement by front advancement. The numerical procedure is implemented in the open source ParMmg software package. It enables the reuse of existing sequential remeshing libraries, a non-intrusive linkage with thirdparty solvers, and a tunable exploitation of distributed parallel environments. We show the efficiency of the approach by comparing interface displacement repartitioning with graph-based repartitioning, and by showing isotropic weak-scaling tests and preliminary anisotropic tests.

Role-shifting threads: Increasing OpenMP malleability to address load imbalance at MPI and OpenMP

“…ParMmg (Cirrottola and Froehly 2019) is a parallel remesher developed by INRIA, based on top of the sequential Mmg remesher. Mesh adaptation is widely used in computational solid mechanics (CSM) and computational fluid dynamics (CFD) domains to improve the quality of the solution.…”

Optimum design and thermal modeling for 2D and 3D natural convection problems incorporating level set‐based topology optimization with body‐fitted mesh

“…Since this part of the solver is performed sequentially on a single MPI process, it is indeed one of the bottlenecks in the current framework. This issue will be addressed once ParMmg (recently developed by Cirrottola and Froehly 93 ), is able to handle implicit surface remeshing.…”

“…Section 3.3.2), in 2D case (see Figure 8), we use the built-in function adaptmesh offered by FreeFEM: For 3D simulation (see Figure 9), the mesh algorithm can be performed by ParMmg, a parallel version of Mmg recently developed by Cirrottola and Froehly. 93 First, the metric is saved by mshmet. Then, we call ParMmg to read the metric and to generate the new mesh using the following script:…”

Parallel Metric-Based Mesh Adaptation in PETSc using ParMmg

“…It includes a 2D local remesher (Mmg2d ), a 3D local remesher (Mmg3d ) and a surface remesher (Mmgs). The 3D local remesher has been parallelized using MPI as ParMmg [9]. Parallel implementations do not currently exist in 2D or for surface remeshing.…”

“…Metric-based mesh adaptation is already available to PETSc's unstructured mesh manager, DMPlex [5,6], using Pragmatic, as documented in a previous IMR research note [7]. The software development efforts documented in this research note build upon the previous work, integrating two new toolkits -Mmg (serial) [8] and ParMmg (MPI-parallel) [9] -as well as providing an interface to DMPlex, with routines for constructing, modifying and combining Riemannian metrics. Python bindings are provided through petsc4py [10], so that downstream packages, such as the Firedrake finite element library [11], may take advantage of these enhancements.…”