Rotorcraft with a tail boom and an integral stabilizer arrangement
A rotorcraft with at least one main rotor and a fuselage, comprising: a tail boom connected to the fuselage, the tail boom extending in a longitudinal direction from the fuselage toward a duct-type portion; a shroud provided at the duct-type portion and forming a transverse duct comprising an air inlet region and an air outlet region; the transverse duct having a longitudinal extension; at least one ducted tail rotor rotatably arranged in the transverse duct; and an integral stabilizer arrangement mounted to the shroud, the integral stabilizer arrangement being embodied in box configuration and arranged laterally on a side of the shroud on which the air inlet region of the transverse duct is arranged.
1 . A rotorcraft with at least one main rotor and a fuselage, comprising:
a tail boom connected to the fuselage, the tail boom extending in a longitudinal direction from the fuselage;
a shroud rigidly secured to the tail boom and forming a transverse duct forming an air inlet region and an air outlet region, the transverse duct comprising a circumferential direction and a longitudinal extension oriented at least essentially perpendicular to the circumferential direction and at least essentially perpendicular to the longitudinal direction of the tail boom;
at least one ducted tail rotor positioned to rotate in the transverse duct; and
an integral stabilizer arrangement formed integrally with the shroud, the integral stabilizer arrangement having a box configuration extending laterally from a side of the shroud on which the air inlet region of the transverse duct is arranged.
2 . The rotorcraft of claim 1 ,
wherein the integral stabilizer arrangement comprises a vertical stabilizer integrally formed with the shroud and having a first aerodynamic profile for providing at least stability of the rotorcraft in yaw.
3 . The rotorcraft of claim 2 ,
wherein the integral stabilizer arrangement comprises at least one horizontal stabilizer mounted to the vertical stabilizer and having a second aerodynamic profile for providing at least stability of the rotorcraft in pitch, the at least one horizontal stabilizer extending from the vertical stabilizer on the side of the shroud on which the air inlet region of the transverse duct is arranged.
4 . The rotorcraft of claim 3 ,
wherein the at least one horizontal stabilizer comprises an upper horizonal stabilizer and a lower horizonal stabilizer, wherein the upper horizontal stabilizer is mounted to the vertical stabilizer, wherein lower horizontal stabilizer is positioned more aft than the upper horizontal stabilizer.
5 . The rotorcraft of claim 3 ,
wherein the integral stabilizer arrangement comprises a profiled connecting strut connecting the horizontal stabilizer to the shroud, the profiled connecting strut spaced apart from the shroud by the horizonal stabilizer on the side of the shroud on which the air inlet region of the transverse duct is arranged.
6 . The rotorcraft of claim 5 ,
wherein the profiled connecting strut extends at an angle generally tangential to the transverse duct.
7 . The rotorcraft of claim 2 ,
wherein the vertical stabilizer extends above the duct and forms a tail fin.
8 . The rotorcraft of claim 1 ,
wherein the integral stabilizer arrangement is positioned behind the central axis of the duct to avoid blockage of airflow.
9 . The rotorcraft of claim 1 ,
wherein the transverse duct comprises a depth oriented at least essentially parallel to the longitudinal extension of the transverse duct, and wherein the depth varies along the circumferential direction of the transverse duct.
10 . A rotorcraft with at least one main rotor and a fuselage, comprising:
a tail boom extending rearwardly in a longitudinal direction from the fuselage;
a shroud forming a duct mounted to a rear end of the tail boom, the duct extending transverse to the longitudinal direction with an air inlet on a first lateral side and an air outlet on a second lateral side;
a counter-torque tail rotor rotatably arranged in the duct; and
a one-sided stabilizer extending laterally from one of the first lateral side or second lateral side of the shroud, the one-sided stabilizer comprising:
a vertical stabilizer segment integrally formed with the shroud,
at least one horizontal stabilizer segment extending from the shroud, and
a connecting strut connected to the at least one horizonal segment to form an open box configuration.
11 . The rotorcraft of claim 10 , wherein the vertical stabilizer segment extends in a vertical direction being generally perpendicular to the longitudinal direction and has an aerodynamic profile which provides stability to the rotorcraft in yaw.
12 . The rotorcraft of claim 10 , wherein the at least one horizontal stabilizer segment comprises an upper horizonal stabilizer segment and a lower horizonal stabilizer segment extending in a transverse direction essentially perpendicular to the longitudinal direction and provide stability to the rotorcraft in pitch, the upper and lower horizontal stabilizer segments extending from the vertical stabilizer segment on the first side of the shroud adjacent the air inlet, wherein the lower horizontal stabilizer segment is positioned more aft than the upper horizontal stabilizer segment.
13 . The rotorcraft of claim 12 , wherein the upper horizontal stabilizer segment is longer than the lower horizontal stabilizer stabilizer, wherein the connecting strut extends between the upper horizonal stabilizer segment and the lower horizontal stabilizer segment.
14 . The rotorcraft of claim 12 ,
wherein the connecting strut extends between the upper and lower horizontal segments at an angle approximately tangentially to the transverse duct.
15 . The rotorcraft of claim 10 , wherein the at least one horizontal segment comprises a first horizonal segment and second horizonal segment, wherein the connecting strut extends between the first and second horizontal segments and is positioned behind the central axis of the duct to avoid blockage of airflow.
16 . The rotorcraft of claim 10 , wherein a transverse depth from the air inlet to the air outlet varies along the circumference of the transverse duct.
17 . A rotorcraft with at least one main rotor and a fuselage, comprising:
a tail boom extending rearwardly in a longitudinal direction from the fuselage;
a shroud forming a duct mounted to a rear end of the tail boom, the duct extending transverse to the longitudinal direction with an air inlet on a first lateral side and an air outlet on a second lateral side;
a counter-torque tail rotor rotatably arranged in the duct; and
a one-sided stabilizer integrally formed with the shroud extending laterally from only the first lateral side adjacent the air inlet, the one-sided stabilizer having at least three stabilizer segments that form an open box configuration,
wherein the at least three stabilizer segments each have an aerodynamic profile and are positioned behind the central axis of the duct to avoid blockage of airflow.
18 . The rotorcraft of claim 17 , wherein the at least three stabilizer segments comprise a vertical stabilizer segment connected to at least one horizontal segment, and a connecting strut connected to the at least one horizonal segment to form an open box configuration,
wherein the vertical stabilizer segment extends in a vertical direction being generally perpendicular to the longitudinal direction and provides stability to the rotorcraft in yaw.
19 . The rotorcraft of claim 18 , wherein the at least one horizontal segment comprises a first horizonal segment and a second horizonal segment extending in a transverse direction essentially perpendicular to the longitudinal direction and provide stability to the rotorcraft in pitch, the first and second horizontal segments extending from the vertical segment on the first side of the shroud adjacent the air inlet.
20 . The rotorcraft of claim 18 ,
wherein the connecting strut extends between the first and second horizontal segments at an angle approximately tangentially to the transverse duct.