Aerodinamički dizajn bespilotne letelice u više faza

Abstract

This paper presents a methodology for aerodynamic optimization of UAV with VTOL capabilities. Aircrafts such as these usually fly at low speeds and due to that low Reynolds numbers are to be expected. The friction drag is highly dependent on the quality of the production process so unless special measures are undertaken, high friction drag coefficients could drastically influence overall performance of the aircraft. Changes of the geometrical parameters influence not only the induced drag of the wing, but also the distribution of the base drag due to sensitivity to changes of the Reynolds numbers. In order to determine the optimal geometrical parameters of the wing, a code for wing performance analysis was written. All necessary factors were calculated by utilizing the Glauert's solution of the Prandtl's equation for multi-segmented wings. By including experimental data of numerous airfoils optimized for low Reynolds numbers, the base drag distribution, along with the induced drag of the wings were calculated for a wide range of angles-of-attack. The obtained results are presented through diagrams and the methodology for the selection of the highest efficiency wing is described. The design of the T - shaped stabilizer was achieved by utilizing analytical methods while the Vortex Lattice Method, DATCOM and CFD were used for verification purposes.