  We study the sensitivity of wall model input variables to the modeling
choices of the outer LES. This work is motivated by sensitivities observed in
dynamic slip wall models. These dynamic wall models use variables from the
near-wall LES solution as inputs to predict the wall stress without relying on
a priori coefficients or equilibrium assumption. Mitigating the sensitivities
in the wall model inputs allows development of robust dynamic wall models. The
effects of SGS model, boundary condition type, numerics, and mesh topology are
assessed through a series of WMLES calculations of turbulent channels.
Probability density functions are computed from planes of the WMLES solutions
at a wall-normal sampling height and are used as a metric for sensitivity.
Sensitivity to SGS model is alleviated when the fraction of total wall stress
carried by the SGS model is held constant. Use of hexagonal close-packed grids
mitigated numerical sensitivities.
