Numerical Study of Turbulent Flow Aerodynamics Around a Multi-Element Airfoil

Abstract

Multi-element airfoils are high-lift devices and provide improved aerodynamic characteristics, which are beneficial for several applications.   The performance of high lift devices was investigated numerically by adapting the 2D viscous, steady, pressure model equations together with the SST  k-ω turbulence model.   Simulations were performed using ANSYS Fluent 24 for the NHLP2D airfoil with a leading edge slat and trailing edge flap.  The flow is considered at a Reynolds number of 1.6x10⁵ and varying angles of attack from 0 to 28 deg.    The parameters that describe the positioning of the slat and flap were tested variables. These variables include deflection angles, gaps, and overlaps. The lift and drag coefficients are evaluated for various configurations.  The results reveal that slats increase the maximum lift on the wing and delay stall, increasing the maximum angle of attack. However, they reduce the lift. In contrast, the flaps increase the overall high-lift configuration airfoil camber, thereby increasing lift.   It was found that for the tested slats and flaps locations, slats with a 2.6% gap, -1.5% overlap and 30° deflection, and flap with a 1.3% gap, 5.3% overlap and 30° deflection was the one with the most favorable performance, generating a Cl_max of 3.81 and Cd of 0.158.