Grid Free is focused on the development of a commercially viable Computational Fluid Dynamics (CFD) software package for the simulation of unsteady, incompressible, high Reynolds number flows.
Our solver is based on the Lagrangian vortex element method used for the grid-free solution of the Navier-Stokes equations. This approach is advantageous over the more commonly used grid-based methods:
Existing grid-based approaches require the meshing of the flow domain, as well as the enclosing boundaries. Volume meshing is complex and expensive to create. The process can be exhaustive especially for external flows and especially moving boundary problems. The vortex-element method requires only surface geometry meshing, providing greater computational efficiency. Its particle-based nature makes it highly suitable for parallelization. Vortex particles evolve only within regions of the flow where there is significant amount of vorticity, such as boundary layers or wake behind bodies. Hence the method attains the efficiency of self-adaptive mesh based methods, without the complexity of mesh refinement and coarsening procedures. This saving allows one to simulate coarse-scale turbulence without using any turbulence model. The approach is especially suited to simulating unsteady flow phenomena which governs most practical processes.
Our package consists of three main modules that treat vortical velocity evaluation, irrotational velocity evaluation and diffusion calculations:
Computational Advantages: scalability / efficiency; a faster, better approach for large problems; adaptivity in space and time.
Package Applicability: unsteady external / internal flows, flows with moving boundary conditions, large eddy simulation.
Computations performed on the Delta HPC SGI Origin 3000 Series high performance supercomputers.
Parallelized fast-solver for vortical velocity evaluation:
VRM solver for diffusion:
Representative Flow Simulation Results:
