A numerical study into the longitudinal dynamic stability of the tailless aircraft

Purpose: The purpose of this research is a study into a mathematical approach of a tailless aircraft dynamic stability analysis. This research is focused on investigation of influence of elevons (elevator) on stability derivatives and consequently on the aircraft longitudinal dynamic stability. The main research question is to determine whether this impact should be taken into account on the conceptual and preliminary stage of the analysis of the longitudinal dynamic stability. Design/methodology/approach: Aerodynamic coefficients and longitudinal stability derivatives were computed by Panukl (panel methods). The analysis of the dynamic stability of the tailless aircraft was made by the Matlab code and SDSA package. Findings: The main result of the research is a comparison of the dynamic stability of the tailless aircraft for different approaches, with and without the impact of elevator deflection on the trim drag and stability derivatives. Research limitations/implications: This paper presents research that mostly should be considered on the preliminary stage of aircraft design and dynamic stability analysis. The impact of elevons deflection on the aircraft moment of inertia has been omitted. Practical implications: The results of this research will be useful for the further design of small tailless unmanned aerial vehicles (UAVs). Originality/value: This research reveals that in case of the analysis of small tailless UAVs, the impact of elevons deflection on stability derivatives is bigger than the impact of a Mach number. This impact should be taken into consideration, especially for a phugoid mode.