Computational Aerodynamics in Aircraft Design: Challenges and Opportunities for Euler/Navier-Stokes Methods

Computational aerodynamics offers one of the most promising means of improving the productivity of the aircraft design process. Evaluation of numerous geometric modifications in a typical design cycle is very costly and time consuming if done using wind tunnels alone. The potential-flow computational methods can provide reliable aerodynamic data needed for aircraft design as long as the flow is entirely subsonic or supersonic and remains attached. Methods based on the Euler and Navier-Stokes equations do not suffer from such restrictions and are, therefore, capable of providing aerodynamic data for a much wider range of flow conditions. Such capabilities are illustrated in this paper. Solutions obtained using a state-of-the-art Three-dimensional Euler/Navier-Stokes Aerodynamic Method, TEAM, are presented for four test cases ranging from an airfoil to the complete advanced tactical fighter prototype configuration. In spite of the superior capabilities, the Euler and Navier-Stokes methods are not yet fully effective for aircraft design since the analysis turn-around time is long and the solution reliability is less than satisfactory. Even at the current level of effectiveness, however, these methods can play a very valuable role in aircraft design by complementing wind-tunnel testing.