NACA 0012 at 10°: Loads, Pressure and Convergence

The run configuration and execution log agree on Mach 0.15, Reynolds number 6,000,000 and 10° incidence. The calculation uses two-dimensional compressible RANS with the SA turbulence model. Chord and reference length are 1 m; reference area is 1 m² for the unit-span model. The wall is adiabatic. The result summary reports 229,376 cells and a maximum y+ of 0.652; that near-wall diagnostic alone does not establish grid independence.

The final surface CSV shows a more negative pressure coefficient on the upper surface near the leading edge, followed by recovery downstream. The upper and lower surface traces provide a direct way to locate the pressure difference. Cp is dimensionless, and the vertical axis is inverted so lower pressure appears higher. The plot represents a single final field, not a time sequence. This makes the leading-edge region a useful focus for subsequent mesh and pressure checks; it does not quantify a local drag contribution.

The final exported coefficients are CL = 1.10403 and CD = 0.0127666. Over continuation iterations 792–891, the recomputed peak-to-peak spans are 0.00011284 in CL and 0.00001273 in CD. A span is max minus min over these 100 samples: it is neither a confidence interval nor a discretization-error estimate. The drag trace is still drifting downward within this small range. The horizontal axis counts iterations, not seconds.

The custom stop record reports that its numerical checks were satisfied. However, the final density residual is −10.2805 while the configured target is below −11. The detailed log table marks that target as unmet, despite a generic success message. We therefore report completion under the custom stop rule and retain the stricter residual limitation. The project report also says grid independence has not been established; no new experimental validation was performed for this article.

Keep the operating condition, reference quantities and iteration window fixed when comparing later candidates. Before interpreting a small drag difference as a geometry benefit, complete the residual check and quantify mesh sensitivity. Surface pressure and the exported coefficients offer a useful baseline now; they do not yet justify an optimized-airfoil claim or an uncertainty bound.