Author(s): A. A. Dimas; P. S. Bernard; J. P. Collins; M. Potts
Linked Author(s):
Keywords: Boundary Layer; Computational Fluid Dynamics; Fast Multipole Method; Large-Eddy Simulation; Parallel Computation; Turbulence; Vortex Method; Vorticity
Abstract: The vortex methodology VorCat (Vortex Computational Algorithm for Turbulence) is applied to the numerical simulation of a turbulent zero-pressure-gradient boundary layer. VorCat is based on a parallel implementation of the Fast Multipole Method for the computation of the velocity field, and includes a hybrid vortex tube and vortex sheet Lagrangian representation of the vorticity field (triangular vortex sheets cover all solid body surfaces while cylindrical vortex tubes may move anywhere in the flow field), a vortex tube creation model that mimics the physical vortex self-replication process, and a vortex hairpin removal and reconnection mechanism to limit the number and scale of vortical structures to those that are dynamically essential. Solid body surfaces are discretized by triangular unstructured meshes. In this paper, results are presented for the tripped turbulent flow developing over a flat plate with periodic boundary conditions in the spanwise direction. The computations are performed on a 64 CPU parallel computer, and the flow field is represented by about 4.500.000 vortex elements. The predicted turbulent flow structures show good qualitative agreement with experimental observations, while the mean turbulent statistics at Reynolds number Reθ=670 compare well with the results of direct numerical simulations.
Year: 2003