  This article analyses the simulation methodology for wall-modeled large-eddy
simulations using solvers based on the spectral-element method (SEM). To that
end, algebraic wall modeling is implemented in the popular SEM solver Nek5000.
It is combined with explicit subgrid-scale (SGS) modeling, which is shown to
perform better than the high-frequency filtering traditionally used with the
SEM. In particular, the Vreman model exhibits a good balance in terms
stabilizing the simulations, yet retaining good resolution of the turbulent
scales. Some difficulties associated with SEM simulations on relatively coarse
grids are also revealed: jumps in derivatives across element boundaries, lack
of convergence for weakly formulated boundary conditions, and the necessity for
the SGS model as a damper for high-frequency modes. In spite of these,
state-of-the-art accuracy is achieved for turbulent channel flow and flat-plate
turbulent boundary layer flow cases, proving the SEM to be a an excellent
numerical framework for massively-parallel high-order WMLES.
