Improving structural weight estimation of novel aircraft configurations to enhance flying quality analysis

Structural weight estimation of novel aircraft configurations, such as a box-wing aircraft, in the conceptual and preliminary design phase is a challenge due to a lack of statistical data. Most of the aircraft performance and handling qualities parameters are strongly influenced by the aircraft weight and inertia. Therefore an accurate weight estimation method is required. The application of existing (statistical) weight estimation methods provides a rather inaccurate and weak estimation for this novel configuration. An alternative is the use of higher fidelity weight estimation methods, which use more physics based calculations and less statistical estimations. A novel design framework with various disciplines is developed. In this framework, a parametric aircraft model, a weight estimation method, aerodynamic analysis and flight mechanics analysis are coupled to perform a fully automated design process. The various modules of this design framework create a decision making system so that the aerodynamic and weight estimations for handling quality measurements can take place with high fidelity for different aircraft category during the preliminary and conceptual design process. It is demonstrated that the design parameters of the PrP300 are closely coupled and a delicate balance has to be found between the design parameters in order to have adequate handling qualities throughout the flight envelope. Such a tradeoff is most likely very difficult, if not impossible to conduct by hand. The proposed framework is therefore a powerful tool to support the aircraft design activities and to investigate the handling qualities of an (unconventional) aircraft already in the early design stages. This can lead to a less error design and consequently decrease the cost due to additional design work and extra wind tunnel and flight testing