DIRECT NUMERICAL SIMULATION OF THE FLOW AROUND A WING SECTION USING HIGH-ORDER PARALLEL SPECTRAL METHODS

Abstract

The results of a DNS of the flow around a wing section represented by a NACA4412 profile, with Rec = 400,000 and 5◦ angle of attack, are presented in this study. The high-order spectral element code Nek5000 is used for the computations. An initial RANS simulation is used to define the velocity boundary conditions, and to design the computational mesh. The agreement between spanwiseand time-averaged fields from the DNS and the RANS simulation is excellent. The mean flow and several components of the Reynolds stress tensor at x/c = 0.4 (β = 0.53) and 0.8 (β = 4.54) are compared with the ZPG boundary layer computed by Schlatter & Örlü (2010). In both cases, the friction Reynolds number is roughly matched (330 and 450), and as expected the Reθ values from the wing (720 and 1,800) are larger than the ones from the ZPG case (612 and 1,007). The APG leads to a steeper log law, a more prominent wake region and a larger U+ e . The tangential turbulence intensity exhibits a stronger inner peak, and starts to develop an outer peak. We also show that the impact on the spanwise component is significant, and also on the wall-normal intensity and the Reynolds shear stress for stronger pressure gradients, especially in the outer region.