UHURA – Validation Experiments

Abstract

Within the UHURA project, three wind tunnel campaigns are performed in three different wind tunnels with two models to cover a broad range of conditions including variation of Krueger span (full span – part span), wing sweep angle and Reynolds number. This work presents the experimental set up and results for the three campaign held in the ONERA L1, DNW-NWB and DNW-LLF wind tunnels. The ONERA experiment features PIV measurements on the lower surface of the 2D wall-to-wall mounted wing in order to obtain a detailed flowfield during the deployment of the Krueger. The transient wall static pressure during the movement of the Krueger is measured with MEMS sensors integrated within the flap and the leading edge. The DNW-NWB investigated the effect of sweep angle over the Krueger flowfield using a 2.5D cantilever wing. In addition to the wall static pressure, the wake of the wing is measured with a 5-hole probe rake. Finally, the effect of Reynolds number is investigated at the LLF facility with the use of a 1:3 scaled wing model with realistic actuation and kinematics to achieve a chord based Reynolds number of 6×〖10〗^6. The LLF campaign features Stereo-PIV measurements on the lower surface of the wing, unsteady wall static pressure and Krueger flap deformation measurements using Stereo pattern recognition (SPR) system.