Numerical Investigations of Ground Effect of Helicopter UAV For Agriculture Application

With objective of spraying pesticide, a classical Helicopter Unmanned Aerial Vehicle (HUAV) was designed, that included one main rotor which generates thrust against gravity and one second rotor in the tail to balance with the main rotor. The designed helicopter was affected based on the blade element theory. For spraying pesticide, HUAV usually flies only around 1-3m from the top of the plant. With such a small distance, effect of ground effect is inevitable. In this paper, the ground effect of HUAV was carried out using ANSYS software. HUAV was flied at 700 RPM of main rotor and 5781 RPM of tail rotor with altitude varying from 0.6D to 1.1D (D was diameter of main rotor). The aerodynamics characteristics of HUAV were estimated using computational fluid dynamic (CFD) tool in ANSYS software. Based on the aerodynamic results, the altitude of HUAV could be chosen to take advantage of the ground effect.