Abstract: Disclosed is a rotor system for an aircraft including a rotor having multiple rotor blades disposed about an axis of rotation of the rotor substantially radially. A plane perpendicular to the axis of rotation, which extends through the rotor blades in a radial direction, forms a rotor plane. A rotor shroud surrounds the rotor circumferentially with regard to the axis of rotation, confines an air duct of the rotor extending in an axial direction of the axis of rotation, and forms a hollow structure extending circumferentially with regard to the axis of rotation. The hollow structure has on its circumferential face facing the rotor in the radial direction an area permeable to gas. The rotor plane intersects the area, and the hollow structure is configured to at least partially absorb acoustic waves of at least one frequency penetrating through the area.

Abstract: Disclosed is a rotor system for an aircraft including a rotor having multiple rotor blades disposed about an axis of rotation of the rotor substantially radially. A plane perpendicular to the axis of rotation, which extends through the rotor blades in a radial direction, forms a rotor plane. A rotor shroud surrounds the rotor circumferentially with regard to the axis of rotation, confines an air duct of the rotor extending in an axial direction of the axis of rotation, and forms a hollow structure extending circumferentially with regard to the axis of rotation. The hollow structure has on its circumferential face facing the rotor in the radial direction an area permeable to gas. The rotor plane intersects the area, and the hollow structure is configured to at least partially absorb acoustic waves of at least one frequency penetrating through the area.