  This article utilizes the Large-Eddy Simulation (LES) paradigm with a
physics-based turbulence modeling approach, including a dynamic subgrid-scale
model and an equilibrium wall model, to examine the flow over the NASA
transonic Common Research Model (CRM), a flow configuration that has been the
focus of several AIAA Drag PredictionWorkshops (DPWs). The current work
explores sensitivities to laminar-to-turbulent transition, wind tunnel mounting
system, grid resolution, and grid topology and suggests current best practices
in the context of large-eddy simulations of transonic aircraft flows. It is
found that promoting the flow transition to turbulence via an array of
cylindrical trip dots, including the sting mounting system in the simulations,
and leveraging stranded boundary layer grids all tend to improve the quality of
the LES solutions. Non-monotonic grid convergence in the LES calculations is
observed to be strongly sensitive to grid topology, and stranded meshes rectify
this issue relative to their hexagonal close-packed (HCP) counterparts. The
details of the boundary layer profiles both at the leading edge of the wing and
within the shock-induced separation bubble are studied, with thicknesses and
integral measures reported, providing details about the boundary layer
characteristics to turbulence modelers not typically available from complex
aircraft flows. Finally, an assessment of the initial buffet prediction
capabilities of LES is made in the context of a simpler NACA 0012 flow, with
computational predictions showing reasonable agreement with available
experimental data for the angle of attack at initial buffet onset and shock
oscillation frequency associated with sustained buffet.
