壁面近傍で低空ホバリングするクアッドロータの吹き返しが回転翼の誘導流れに与える影響

Abstract

One of the problems with multirotors is that when flying near a wall, such as during infrastructure inspections, the companion flow passing through the rotor blades is blown back by the ground or wall surface, causing instability in the flight attitude of the aircraft(1)(2). As a previous study on this phenomenon, as part of the development of a quadrotor capable of autonomous flight even in complex narrow spaces, we focused on a small quadrotor with four rotors among multi-rotors and investigated the effect on aerodynamic characteristics when hovering near a wall, and found that even at heights outside the ground effect, the direction and position of sidewalls Ground effect The results showed that even at heights outside the ground effect, the direction and position of the sidewalls increased the thrust of the wall-side rotor due to the blowback effect, causing the aircraft to tilt (roll) at some positions. In this study, to clarify the effect of the wake interference of quad rotor on the induced flow, we investigated the tip vortex trajectry and the induced flow velocity in the high thrust and rolling region(posture tilted backward against the wall) using a high-speed camera, a hot-wire anemometer, respectively. We show some of reasons to increase the thurust of wall side roters.