Aerodynamic investigations on a helicopter fuselage with rotor hub

The focus of this investigation is on the flow around a helicopter fuselage with rotor hub. The shape of the wind tunnel model which is used for the experimental studies is based on a light-transport-helicopter with conventional rotor. The model is equipped with a powered main rotor hub. The results include force measurements with an internal six-component balance and velocity measurements with hot-wire anemometry. The aerodynamic forces and moments acting on the helicopter depend strongly on the variation of angle of attack and sideslip. The empennage, which is mounted on the helicopters tail and provides the helicopter with aerodynamic stability in forward flight, is partially responsible for this dependence. The wake of the fuselage and rotor hub consists of different vortices, generated at different positions on the helicopter fuselage. The structure of these vortices changes with variation of the angle of attack.