Design of the grand touring sports car wing

Abstract

This study evaluated the adaptation of natural laminar flow airfoils forGrandTouring (GT) sports car racing and the influence of wing geometry and flow control devices on rear-wing aerodynamics. The mean camber lines for the National Advisory Committee for Aeronautics (NACA) 651-412 and National Aeronautics and Space Administration (NASA) LS(1)-0413 airfoils were calculated. Numerical analysis was conducted using thin-airfoil theory and finite-wing theory. Airfoil variables included zero-lift angle of attack and centre-of-pressure location. Wing variables encompassed induced and effective angles of attack, lift and drag coefficients, and lift-to-drag ratio. Modelling consisted of variations in wing aspect ratio and the integration of end plates and a Gurney flap. A tapered rectangular planform is quasi-elliptical and attains near-unity Oswald efficiency. The NASA LS(1)-0413 airfoil is stall resistant and produces high downforce at the expense of extra drag because of factors related to camber, profile thickness, leading edge radius, and concave pressure recovery. The wing should be set at an incidence above that for best lift-to-drag ratio. The NACA 651-412 airfoil is aerodynamically more efficient but produces less downforce and may be used as a stabilizer. Augmented aspect ratio, end plates, and a Gurney flap enhance wing aerodynamics via flow control and modified downwash configuration. Theanalysis suggests that a tapered LS(1)-0413 wing of 5.56 aspect ratio fitted with end plates and a Gurney flap, set at high incidence, is an appealing single-element arrangement for applications in Grand Touring sports car engineering.