Stereo PIV Measurements of Low-Aspect-Ratio Low-Reynolds-Number Wings with Sinusoidal Leading Edges for Improved Computational Modeling

Abstract

Stereo Particle Image Velocimetry measurements of the flow field around a unity aspect ratio wing with a sinusoidal leading-edge have been carried out at a Reynolds number Re = 140, 000 for two angles of attack, α α α α = 0º and 15º. These measurements are intended to be used for improved computational modeling of the flow employing Detached Eddy Simulations. For this reason, numerical predictions have also been carried out for the mentioned flow cases, using both the "F2-shielded" modeling and the "delayed" modeling approaches for the SST k-ω turbulence model, as well as a reference Reynolds-Averaged Navier-Stokes calculation. The results have demonstrated the superior performance of the "delayed" modeling at high incidence. However, the latter approach unexpectedly fails at low incidence, hence indicating the need for improved boundary layer transition modeling.Nomenclature AR = aspect ratio α = angle of attack C L = lift coefficient c = wing chord, m Re = Reynolds number

Mimicking the humpback whale: An aerodynamic perspective

“…Delgado et al [112] carried out Stereo Particle Image Velocimetry (SPIV) measurements and numerical simulation on the NASA LS (1)-0417 airfoil at Re 1.4 Â 10 5 . The experimental setup was similar to that of Zhang et al [81].…”

“…Camara and Sousa [94], Guerreiro and Sousa [111] and Delgado et al [112] carried out experimental (force balance, SPIV) and numerical (LES, DNS, DES and DDES) studies.…”

Reynolds Number Effect of Leading Edge Tubercles on Airfoil Aerodynamics

“…A more thorough summary of the flow and geometric conditions of studies performed on tubercled airfoils can be seen in Table 1. 11 NACA 65-(12)10 2.0 × 10 5 , 6 × 10 5 Delgado et al 12 NASA LS(1)-0417 1.4 × 10 5 Karthikeyan et al 13 NACA 4415 1.2 × 10 5 Fernandes et al 14 NACA 2412 2.185 × 10 6 Skillen et al 15 NACA 0021 1.2 × 10 5 Guerreiro and Sousa 16 NASA LS(1)-0417 7.0 × 10 4 , 1.4 × 10 5 Hansen 10 NACA 0021, NACA 65-021 4.37 × 10 3 , 5.25 × 10 3 Hansen et al 17 NACA 65-012 1.2 × 10 5 Johari et al 4 NACA 63 4 -021 1.83 × 10 5 Levshin et al 18 NACA 63 4 -021 1.83 × 10 5…”

Combined passive and active flow control for fixed-wing micro air vehicles

“…10 In parallel to the experimental efforts, numerical predictions of the flow around the baseline and modified wings have subsequently been performed employing panel methods, 11 Reynolds-Averaged Navier-Stokes (RANS) approaches using different turbulent modelings such as Spalart Allmaras, 12 k−ε, 13,14 k−ω0.25emSST, 15–17 and RANS transition models such as γ−Reθ. 18 Furthermore, Direct Numerical Simulation (DNS), 19,20 Large Eddy Simulation (LES), 21,22 and hybrid RANS-LES models 23–25 have also been utilized to yield a better understanding of the unsteady flow behavior. In a nutshell, all of the previous investigations indicated that the tubercles in the leading edge enabled flow manipulation, eventually delaying the occurrence of stall.…”