Mechanistic insights into rotational curvature correction for turbulence modeling in high angles of attack separated flows

Accurately simulating rotational and curvature effects remains a central challenge in turbulence modeling. This study investigates the effect of rotational curvature correction on the SST-DDES method in high angles of attack separated flow over the NACA4412 airfoil and its underlying mechanism. We reveal a novel physical mechanism whereby the rotational and curvature correction suppresses vortex stretching-particularly in streamwise and spanwise directions-via the curvature-sensitivity function F _{r 1}, leading to reduced enstrophy. Key consequences include decreased vorticity growth, lower turbulent kinetic energy, and inhibited dissipation. Consequently, non-physical dissipation in the vortex core is significantly reduced, yielding sharper vortical structures and more accurate unsteady flow evolution. The identified chain of mechanisms-suppressed stretching, reduced enstrophy, and rebalanced production/dissipation-provides profound insight into curvature-sensitive flows.