An Innovative Route from Wind Tunnel Experiments to Flight Dynamics Analysis for a Highly Swept Flying Wing

Abstract

A flying wing configuration with highly swept leading edges and low aspect ratio such as the generic UCAV configuration DLR-F19 is very attractive for military applications due to its very favorable stealth capabilities. As the assurance of good flying qualities, however, is a critical aspect for such a configuration, it should be considered early in the design process. This paper presents an innovative way to derive a flight dynamics model from wind tunnel experiments by applying a system identification approach, normally employed for flight test. This allows the modelling of nonlinear aerodynamic effects and provides a model which can be directly integrated into flight dynamics simulations. New wind tunnel maneuvers are applied which significantly reduce the time of the wind tunnel experiments and improve the quality of the aerodynamic dataset generation. The aerodynamic model is then integrated into a 6-DoF simulation environment in order to perform a flight dynamics analysis of the UCAV configuration. The purpose of this analysis is to compare the flying qualities as derived from wind tunnel data with the results determined on the basis of data from VSAERO, a low-fidelity aerodynamic tool used in preliminary aircraft design.