A systematic study of the grid requirements for a spectral element method solver

Abstract

In this paper, direct numerical simulation of fully developed turbulent channel flow is carried out at low Reynolds number, Reτ=180, in order to investigate in a spectral element method context the effect of grid refinement on turbulence statistics. Mean flow, turbulence intensities, skewness, viscous dissipation, and energy spectra were computed, alongside planar visualisations of the flow. The findings show C0 continuity, present at shared nodes between adjacent spectral elements, creates at element interfaces potential artefacts in the averaged statistical quantities. However, grid convergence is fast for spatially-averaged terms, particularly for statistics of primitive variables, but ma..