This paper presents an original Hexacopter with three nonplanar rotor pairs where the variable thrust is provided by fixed-pitch rotors with variable speed. The corresponding face-to-face rotor pair (F–F) and back-to-back rotor pair (B–B) are proposed as the research components to maximize the overall aerodynamic performance with different transverse spacings and disk plane angles. Together with the rotor interactions involved in low Reynolds number (Re) environments, experiments in the presence of the uncertainty analysis are performed to validate the aerodynamic interference and test the effectiveness of the proposed rotor pairs. Experimental results show that the performance of the rotor pair can be improved significantly by having an optimal combination with a larger angle and a moderate spacing. Indeed, the aerodynamic interactions between the two rotors decrease with a larger disk plane angle, and the aerodynamic interference of the rotor pairs is mainly involved in the face to face type. Furthermore, parametric studies were also performed to study the effects of low Re and to attempt to maximize the thrust and minimize the total power required in hover flight. Useful conclusions are provided for the further aerodynamic analysis and control strategy to meet design requirements.

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