Abstract
A multi-element airfoil flow shows inherently strong complexity for variations in angle of attack and slat and flap settings in high-lift systems. So far, several CFD code validations have been undertaken for high-lift flows. However, in spite of a great deal of efforts, even in two-dimensional computations, the current CFD codes fail to predict flow phenomena that govern high-lift aerodynamics with sufficient accuracy and efficiency. Currently, a two-dimensional compressible Navier-Stokes code with Spalart-Allmaras one-equation turbulence model and an unstructured multigrid method was developed and newly incorporated into a CFD-based design system of TRDI-JDA. For the code validation, the subsonic flows around two- and five-element airfoil configurations are computed. With respect to wing surface pressure coefficient distributions, boundary-layer velocity profiles and forces and moment coefficients, the present computed results are compared quantitatively with the wind-tunnel testing data. As a result, the present code is expected to be a powerful tool to predict and improve high-lift characteristics of multiple elements in aircraft design process.
