History effects for cambered and symmetric wing profiles

Authors: Tanarro, A.T., Vinuesa, R., Schlatter, P.
Document Type: Article
Pubstate: Accepted
Journal: 12th ERCOFTAC Symp. on Engineering Turbulence Modeling and Measurements (ETMM12), Montpellier, France, September 26-28
Year: 2018


The characteristics of complex turbulent boundary layers under adverse pressure gradients are assessed through well-resolved large-eddy simulations (LES) with the spectral-element code Nek5000. Two wing sections are analysed: a NACA0012 at 0 • angle of attack which presents a mild adverse-pressure gradient (APG) along the chord and a NACA4412 at 5 • angle of attack with a strong adverse pressure gradient on the suction side, both profiles at Re c = 400, 000. The turbulent statistics show that the mild-APG turbulent boundary layer (TBL) of the NACA0012 presents a slight deviation of the velocity fluctuations in the outer region while the strong-APG TBL of the NACA4412 shows significantly larger fluctuations throughout the wall-normal direction with respect to the zero-pressure-gradient (ZPG) TBL. These differences are more substantial in the outer region of the boundary layer. Spectral analyses show that the APG has a significant impact on the largest scales in the boundary layer. Our results indicate that the APG increases the turbulent kinetic energy (TKE) of the TBL, more prominently in the outer layer, and suggest a different mechanism than the one related to high Re in ZPGs.