Antepara, O.; Borrell, R.; Lehmkuhl, O.; Oliva, A.
International Conference on Parallel Computational Fluid Dynamics
Data de presentació: 2014-05-20
Presentació treball a congrés
Adaptive mesh refinement (AMR) methods focus on the refinement/coarsening of certain zones of the mesh according to the dynamic characteristics of the flow, in order to get a suitable grid resolution at any part of the domain and time step of a numerical simulation.
The benefit from this method is an automatic and dynamic mesh adaptation to accurately solve flow problems, otherwise the construction of a fixed (static) mesh needs a maximum grid resolution to be established, from the beginning of the simulation, in zones that will not be required in other time step of the simulation.
Apart from reducing the computing requirements for the simulation, it is also important that the algorithm achieves a good parallel performance in current supercomputers, to take advantage of the increasingly available computing power. In order to accomplish these objectives, the development of a parallel adaptive mesh refinement code for three-dimensional structured meshes on distributed-memory machines is presented. Our AMR scheme applies a cell-based refinement technique, where an octree data structure is used keeping track of the cells connectivity through the different levels of refinement and a physics-based refinement criteria is developed based on the variational multi-scale (VMS) decomposition theory. This approach has been validated in turbulent problems around bluff bodies in 2D and 3D domains.
The proposed work focuses on the parallelization strategy and includes a performance study of the algorithm. The overall AMR process, from the selection of the cells to be refined/coarsened to the partitioning and pre-processing of the resulting mesh has been implemented in parallel and tested on a AMD Opteron based supercomputer.
Finally, the applicability, robustness and accuracy of our algorithm is shown on the numerical simulation of the turbulent flow around a wall mounted cube at Re=7235. which reproduces some of the turbulent flows features around bluff bodies, i.e. flow separation, vortex shedding and appearance of vortex at the upstream face and in the wake of the cube.