Aircraft

An aircraft, comprising:

• at least two propulsion units being pivotable provided on the aircraft, the propulsion units being arranged adjacent to each other along an arrangement direction and respectively comprising:
• a propulsion rotor being rotatable about a rotation axis, configured to contribute in thrust generation, and configured to suck air along an airflow direction substantially perpendicular to the arrangement direction;
• and
• a duct configured to guide air to the propulsion rotor, the duct comprising a non-circular inlet portion, a circular downstream portion being substantially circular about the rotation axis and being located downstream of the inlet portion along the airflow direction, and an air guiding portion guiding air from the non-circular inlet portion to the circular downstream portion and establishing a transition therebetween, the air guiding portion having an upper and a lower air guiding portion spaced apart from each other and provided on respective upper and lower sides of the rotation axis;
• and
• at least one septum interposed between two rotation axes of two adjacent propulsion rotors, the at least one septum extending on the upstream side along the airflow direction with respect to the circular downstream portion and between the upper and lower air guiding portions, the at least one septum having a guiding surface having at least one tangential plane parallel to the rotation axis, wherein the at least one septum protrudes to an upstream side of a leading edge plane of the inlet portion,
• wherein the at least one septum at least partially extends up to a leading edge plane of the inlet portion, the leading edge plane being a plane perpendicular to the air flow direction and comprising at least part of a leading edge of the duct, and
• wherein the at least one septum extends entirely up to the leading edge plane of the inlet portion.

An aircraft, comprising:

• at least two propulsion units being pivotable provided on the aircraft, the propulsion units being arranged adjacent to each other along an arrangement direction and respectively comprising:
• a propulsion rotor being rotatable about a rotation axis, configured to contribute in thrust generation, and configured to suck air along an airflow direction substantially perpendicular to the arrangement direction;
• and
• a duct configured to guide air to the propulsion rotor, the duct comprising a non-circular inlet portion, a circular downstream portion being substantially circular about the rotation axis and being located downstream of the inlet portion along the airflow direction, and an air guiding portion guiding air from the non-circular inlet portion to the circular downstream portion and establishing a transition therebetween, the air guiding portion having an upper and a lower air guiding portion spaced apart from each other and provided on respective upper and lower sides of the rotation axis;
• and
• at least one septum interposed between two rotation axes of two adjacent propulsion rotors, the at least one septum extending on the upstream side along the airflow direction with respect to the circular downstream portion and between the upper and lower air guiding portions, the at least one septum having a guiding surface having at least one tangential plane parallel to the rotation axis, wherein the at least one septum protrudes to an upstream side of a leading edge plane of the inlet portion,
• wherein the at least one septum has a non-concave shape when seen along the arrangement direction,
• wherein the at least one septum has a convex shape along substantially its entire length when seen along the arrangement direction.