Numerical Investigation on Two Airfoil Design Codes Based on the Euler and Navier-Stokes Equations

Abstract

Under the framework of the DLR-CAE cooperation topic: 92-16, numerical investigation is carried out on two airfoil analysis/ design codes at the Institute of Design Aerodynamics, DLR, Braunschweig. The first code is the DLR Airfoil Design Method based on the solutions of the Euler/Navier-Stokes eqs., and the other is the ISES Transonic Airfoil Analysis/Design code of MIT, which uses the Euler eqs. with viscous correction. This report summarizes the design part of the investigation where both methods are compared with each other through design studies of transonic airfoils in inviscid and viscous flows. The design examples include the redesign of existing airfoils, design under ill-posed conditions, design with arbitrarily prescribed target C* distributions, modifying NLF airfoilss by changing the slopes of the favourable pressure gradients and the design of new NLF airfoils.