Aircraft

Abstract

The present invention relates to an aircraft, and the problem is to reduce the drag borne by the strut during cruising. The aircraft of the present invention includes a fuselage, a front wing and a rear wing that extend laterally from the fuselage and generate lift during cruising, a strut (18) that is supported by the front wing and the rear wing so as to be separated from the fuselage, and at least one VTOL rotor having one or more blades that generate a vertical thrust during takeoff and landing and is supported on the strut. The strut has a shape in which the main body portion bends in a direction separated from the fuselage with respect to the front end and the rear end and extends in the front-rear direction when viewed from above, and has a cross-sectional shape that is smoothly curved on the upper side, tapers from the upper side to the lower side, and is substantially flat on the lower side when viewed from the front. Since the strut has a cross-sectional shape that is smoothly curved at the upper end, tapers from the upper side to the lower side, and is substantially flat on the lower side when viewed from the front, it is possible to eliminate or suppress the disturbance of the air flow, thereby reducing the air drag borne by the strut during cruising and enabling cruising with less resistance.

Description

Technical Field

[0001] The present invention relates to an aircraft. Background Art

[0002] In the prior art, a vertical takeoff and landing aircraft (referred to as a vertical takeoff and landing machine or simply an aircraft) is known, which takes off and lands in the vertical direction by using takeoff and landing (VTOL) rotors arranged on the left and right sides of the fuselage, and flies in the horizontal direction by using a cruising rotor arranged at the rear of the fuselage. Here, Patent Document 1 discloses an aircraft having a boom control effector configured to have a teardrop shape (also referred to as a wing shape) so that the airflow (downwash) generated by the VTOL rotor is directed downward and the direction of the airflow is controlled. On the other hand, in order to limit the entire fuselage within a specified size and arrange a plurality of larger rotors, a plurality of VTOL rotors are arranged on the side of the fuselage in a non-linear shape (for example, refer to Patent Document 2).

[0003] Patent Document 1: U.S. Patent Application Publication No. 2019 / 0135425;

[0004] Patent Document 2: U.S. Patent Application Publication No. 2019 / 0047342. Summary of the Invention

[0005] [Problems to be Solved by the Invention]

[0006] However, in order to support a plurality of non-linearly arranged VTOL rotors with one boom, it is necessary to form the boom so as to be bent laterally and extend in the front-rear direction. Such a bent boom has a problem of being subjected to strong resistance when the aircraft is cruising.

[0007] [Means for Solving the Problems]

[0008] In one aspect of the present invention, there is provided an aircraft including: a fuselage; a wing fuselage extending laterally from the fuselage and generating lift during cruising; a boom supported by the wing fuselage separately from the fuselage; and at least one rotor supported on the boom and having one or more blades generating a vertical thrust during takeoff and landing, the boom having a shape in which the main body portion is bent in a direction away from the fuselage with respect to the front end and the rear end and extends in the front-rear direction when viewed from above, and having a cross-sectional shape that is smoothly curved on the upper side, tapers from the upper side to the lower side, and is substantially flat on the lower side when viewed from the front.

[0009] In addition, the above summary of the invention does not enumerate all the features of the present invention. Moreover, sub-combinations of these feature groups can also form an invention. Brief Description of the Drawings

[0010] Figure 1The structure of the aircraft of this embodiment is shown in the top view.

[0011] Figure 2A The internal structure of the boom is shown.

[0012] Figure 2B The structure of the radiator is shown in the front view.

[0013] Figure 2C The structure of the radiator is shown in the side view.

[0014] Figure 2D The structure of the cooling circuit is shown.

[0015] Figure 3 Shown is related to Figure 2A The sectional structure of the air flow guiding structure related to the reference line CC in

[0016] Figure 4A The structure of the upper side of the air flow guiding structure and the configuration of the inlet are shown.

[0017] Figure 4B The structure of the lower side of the air flow guiding structure and the configuration of the outlet are shown.

[0018] Figure 5A The shape of the boom of the comparative example is shown.

[0019] Figure 5B The numerical fluid dynamics analysis results of the air resistance (pressure distribution in the vertical cross-section) borne by the boom of the comparative example during cruise are shown.

[0020] Figure 5C The numerical fluid dynamics analysis results of the air resistance (pressure distribution in the front-rear cross-section) borne by the boom of the comparative example during cruise are shown.

[0021] Figure 6A The shape of the boom of this embodiment is shown.

[0022] Figure 6B The numerical fluid dynamics analysis results of the air resistance (pressure distribution in the front-rear cross-section and vertical cross-section) borne by the boom of this embodiment and the boom of the comparative example during cruise are shown.

[0023] Figure 6C The numerical fluid dynamics analysis results of the air resistance borne by the boom of this embodiment and the boom of the comparative example during cruise and vertical takeoff and landing are shown.

[0024] Figure 7A Examples of the boom shape and the configuration of the cooling device are shown.

[0025] Figure 7B Shown for Figure 7ANumerical fluid dynamics analysis results of the air resistance borne by each of the plurality of booms shown during cruise and VTOL. Detailed implementation

[0026] The present invention will be described below through embodiments of the invention. However, the following embodiments do not limit the invention within the scope of protection of the claims. In addition, not all combinations of features described in the embodiments are necessary for the solution of the invention.

[0027] Figure 1 In the top view, the structure of the aircraft 100 of the present embodiment is shown. The aircraft 100 is a vertical take-off and landing aircraft, equipped with rotors having an electric motor as a drive source, generating thrust using the take-off and landing (VTOL) rotors to take off and land in the vertical direction, and generating thrust using the cruise rotors (also called Cruise rotors) to fly horizontally. The aircraft 100 is also a hybrid aircraft, capable of operating the electric motor using the power supplied from the battery and the electric generator respectively, and charging the battery using the electric generator. In particular, the aircraft 100 of the present embodiment is equipped with booms capable of suppressing the resistance borne during cruise, and includes a fuselage 12, a front wing 14, a rear wing 16, two booms 18, eight VTOL rotors 20, two cruise rotors 29, a cooling system 60, and an air flow guiding structure 70. In addition, the rotation surfaces and rotation directions of one or more blades 23 of the VTOL rotors 20a, 20b, 20c, 20d are indicated using double-dashed lines and arrows.

[0028] The fuselage 12 is a structure that provides a space for crew members, passengers to board, and carry goods, etc., and houses devices such as a storage battery and an electric generator (both not shown). The fuselage 12 is symmetric about the central axis L, extends in the front-rear direction parallel to the central axis L, and has a slender shape in the left-right direction orthogonal to the central axis L in the horizontal plane. Here, the direction parallel to the central axis L is set as the front-rear direction, the left side and the right side of the drawing are set as the front (F) and the rear (B) respectively, the direction orthogonal to the central axis L in the horizontal plane is set as the width direction (or left-right direction), and the upper side and the lower side of the drawing are set as the right side (R) and the left side (L) respectively. In addition, the vertical direction is orthogonal to these front-rear direction and width direction respectively, and the upward and downward directions in the vertical direction are also called the upper side (U) and the lower side (L) respectively. The fuselage 12 has a smoothly curved front end when viewed from above and a rear end parallel to the width direction that is slightly narrower than the main body.

[0029] The front wing 14 is a wing-body that extends laterally from the fuselage 12 and generates lift by moving forward during cruising, and functions as a canard wing of the aircraft 100. The front wing 14 has a V-shape in which two wing-bodies extend from the center part to the left front and the right front respectively, and is fixed to the upper part of the front side of the main body of the fuselage 12 at the center part in such a way that the opening of the V-shape faces forward. The front wing 14 includes elevators 14a disposed at the trailing edges of the two wing-bodies respectively.

[0030] The rear wing 16 is a wing-body that extends laterally from the fuselage 12 and generates lift by moving forward during cruising, and functions as a swept wing for reducing air resistance. The rear wing 16 has a V-shape in which two wing-bodies extend from the center part to the left rear and the right rear respectively, and is fixed to the upper part of the rear end of the fuselage 12 at the center part via a pylon 32 in such a way that the opening of the V-shape faces rearward. The rear wing 16 includes ailerons 16a arranged in a plurality of lines on the two wing-bodies respectively and vertical fins 16b arranged at the wing tips.

[0031] Here, the wing area of the rear wing 16 is larger than that of the front wing 14, and the wing width of the rear wing 16 is larger than that of the front wing. Thus, when moving forward, the lift generated by the rear wing 16 is larger than the lift generated by the front wing 14, and the rear wing 16 functions as the main wing of the aircraft 100. In addition, the wing area, length, etc. of the front wing 14 and the rear wing 16 can be determined based on the balance of the lift generated by each, the position of the center of gravity, the attitude of the airframe during cruising, etc.

[0032] The two booms 18 are structures supported separately from the left and right of the fuselage 12 by the front wing 14 and the rear wing 16, and function to support or accommodate various structural parts of the VTOL rotors 20 and the cooling system 60 described later. The two booms 18 have a cylindrical shape in which the main body part is curved in an arc shape in a direction separating from the front end and the rear end and extends in the front-rear direction when viewed from above, and have a cross-sectional shape that is smoothly curved on the upper side, gradually tapers from the upper side to the lower side, and is substantially flat on the lower side (i.e., substantially parallel to the front-rear, left-right directions) when viewed from the front, and are arranged symmetrically with respect to the fuselage 12 (i.e., the central axis L) in a pair. In addition, the two booms 18 extend in the front-rear direction and are curved in an arc shape in the width direction, but are not limited to an arc shape and may be curved into a hook shape. The front end portions of the two booms 18 are located at a position forward of the front wing 14, and are supported at the tips of the front wing 14 in the front side main body part (between the two front VTOL rotors 20a, 20b), and the rear end portions are located at a position rearward of the rear wing 16, and are supported at the rear wing 16 in the rear side main body part (between the two rear VTOL rotors 20c, 20d).

[0033] Figure 2AShows the internal structure of the boom 18. The boom 18 includes a skin 18a, ribs 18b, and a beam 18c. The skin 18a is a component that forms the surface of the boom 18, has an airfoil cross-sectional shape, and is formed into a cylindrical shape that is arcuately bent laterally and extends in the front-rear direction. The skin 18a bulges upward at the location where the VTOL rotor 20 is disposed, and expands in the left-right direction to form a space 18d. At the location where the cooling system 60 is disposed, it bulges slightly upward and expands in the left-right direction to form a space 18e. The rib 18b is a plate-shaped component with an airfoil shape, is disposed at multiple locations in the front-rear direction, and holds the skin 18a from the inside. In addition, the spaces 18d and 18e inside the boom 18 are divided by the rib 18b. The beam 18c is a rod-shaped component that extends in the front-rear direction and forms a framework for supporting the rib 18b and other components. In addition, the shape of the boom that can suppress the drag experienced during cruising will be described later.

[0034] Eight VTOL rotors 20 (20a to 20d) are supported by two booms 18 and are rotors that generate vertical thrust during takeoff and landing. Four of the eight VTOL rotors 20a to 20d are supported by the left boom 18 at substantially equal intervals, and the remaining four VTOL rotors 20a to 20d are supported by the right boom 18 at substantially equal intervals. Here, the VTOL rotor 20a is disposed at the forefront, two VTOL rotors 20b and 20c are disposed front and rear between the front wing 14 and the rear wing 16, and the VTOL rotor 20d is disposed at the rearmost. Among the left VTOL rotors 20a to 20d and the four right VTOL rotors 20a to 20d, two left and right VTOL rotors 20a to 20d that are equivalent in position in the front-rear direction are paired and, as Figure 1 shown, are controlled to rotate in opposite directions to each other. Unless otherwise specified, each of the eight VTOL rotors 20a to 20d is simply referred to as the VTOL rotor 20.

[0035] The VTOL rotor 20 has one or more blades 23, a motor 21, and an inverter 22. In addition, the motor 21 and the inverter 22 are also referred to as electrical components. In addition, in Figure 2A shows the structure of the left VTOL rotor 20c and the internal structure of the left boom 18 that houses this structure to represent the eight VTOL rotors 20.

[0036] As Figure 2A shown, one or more blades 23 are wing-shaped components that are supported on the boom 18 and generate thrust in the vertical direction by rotating. In the present embodiment, the number of blades 23 is two, but it can also be any number of one or three or more. One or more blades 23 are supported at a position higher than the front wing 14 and the rear wing 16. In addition, in Figure 1 uses a double-dashed line to represent the rotation plane of one or more blades 23 of each VTOL rotor 20.

[0037] The motor 21 is an electric motor having a rotation axis 21a oriented in the vertical direction and rotating a blade 23 fixed to the tip via the rotation axis 21a. It is supported by the beam 18c via a support member and is housed in the space 18d of the boom 18.

[0038] The inverter 22 is a device that receives DC power supply from a storage battery, converts it into AC power, and supplies it to the motor 21. It is supported by the beam 18c below the motor 21. The inverter 22 can control the rotation speed of the motor 21.

[0039] The two cruising rotors 29 are rotors supported at the rear end of the fuselage 12 and generating thrust during cruising. The cruising rotors 29 are arranged side by side with respect to the central axis L within a cylindrical duct 54 fixed to the rear end of the fuselage 12, and include: one or more blades supported within the duct 54 and generating thrust forward by rotation; a motor having a rotation axis oriented in the front-rear direction and rotating one or more blades fixed to the tip via the rotation axis; and an inverter that receives DC power supply from a battery, converts it into AC power, and supplies it to the motor (not shown in the figure). The inverter can control the rotation speed of the motor.

[0040] The cooling system 60 cools the motor 21 and the inverter 22 that constitute the VTOL rotor 20 in a liquid cooling manner using a radiator 61 disposed within the boom 18. In the present embodiment, one cooling system 60 is provided for a plurality (for example, two) of VTOL rotors 20, and a total of four cooling systems 60 are provided. However, this is not limiting, and one cooling system 60 may be provided for one VTOL rotor 20. The cooling system 60 includes a radiator 61, a pump 62, a coolant tank 63, and pipes 64, 65. In addition, water can be used as the coolant.

[0041] In Figure 2B and Figure 2C the structure of the radiator 61 is shown in a front view and a side view, respectively. The radiator 61 is a heat exchanger that cools the coolant used to cool the motor 21 and the inverter 22. In addition, the radiator 61 is supported between two ribs 18b using a support member 61f and is housed within the boom 18 by an air flow guiding structure 70 described later. The arrangement of the radiator 61 within the boom 18 will be described later. The radiator 61 has a plurality of tubes 61a for allowing the coolant to flow up and down, a plurality of fins 61b respectively fixed to the plurality of tubes 61a to increase the surface area in contact with the air flow, an upper tank 61c for supplying the coolant to the plurality of tubes 61a, a lower tank 61d for receiving the coolant from the plurality of tubes 61a, and two fans 61e for supplying the air flow to the plurality of fins 61b.

[0042] A plurality of tubes 61a are arranged horizontally and assembled with a plurality of fins 61b to form a rectangle in a front view. An upper tank 61c is fixed to the upper side thereof, and a lower tank 61d is fixed to the lower side thereof, constituting a radiator main body. By the operation of a pump 62 described later, the coolant heated by circulating through the motor 21 and the inverter 22 is sent into the upper tank 61c via a pipe 64, flows downward from the plurality of tubes 61a respectively, is cooled and conveyed to the lower tank 61d, and is conveyed to the motor 21 and the inverter 22 via a pipe 65. At this time, two fans 61e operate to send air flow from one side ( Figure 2C the right side in) of the radiator main body into contact with the plurality of fins 61b, so that heat exchange is performed between the air flow and the radiator main body. The heated air flow detaches from the other side ( Figure 2C the left side in) of the radiator main body and is discharged.

[0043] The pump 62 is connected to the radiator 61 via a pipe 65, receives the cooled coolant from the radiator 61 and sends it into the motor 21 and the inverter 22. At the same time, the coolant heated by the motor 21 and the inverter 22 is sent into the radiator 61 via a pipe 64.

[0044] The coolant tank 63 is a container for storing coolant. For example, when the coolant is insufficient, coolant is conveyed from the coolant tank 63 to the cooling circuit to supplement the coolant.

[0045] The pipes 64 and 65 are components for conveying coolant, connecting the radiator 61 and the pump 62 to the motor 21 and the inverter 22, and constituting a cooling circuit for the coolant to circulate.

[0046] Figure 2D The structure of the cooling circuit is shown. Using the pipe 64, the upper tank 61c of the radiator 61 is connected to the motor 21 and the inverter 22. In addition, in this embodiment, one cooling system is provided for two VTOL rotors 20. Therefore, the illustrated motor 21 refers to a motor formed by connecting the motors 21 of two VTOL rotors 20 in series or in parallel, and the illustrated inverter 22 refers to an inverter formed by connecting the inverters 22 of two VTOL rotors 20 in series or in parallel. Using the pipe 65, the lower tank 61d of the radiator 61 is connected to the motor 21 and the inverter 22 via the pump 62. The coolant tank 63 is connected to the pipe 65. By the operation of the pump 62, the coolant heated in the motor 21 and the inverter 22 is conveyed to the radiator 61 via the pipe 64, and the coolant cooled by the radiator 61 is conveyed to the motor 21 and the inverter 22 via the pipe 65.

[0047] It should be noted that in the cooling circuit provided by the cooling system 60, the motor 21 and the inverter 22 are connected in series downstream of the pump 62, but they can also be connected in parallel instead. In addition, other electrical components can also be connected in series or in parallel with the motor 21 and the inverter 22. In addition, in the cooling system 60, the cooling circuit is configured to cool both the motor 21 and the inverter 22 by using one radiator 61, one pump 62, and one tank 63, but it can also be replaced by respectively connecting the radiator 61, the pump 62, and the tank 63 to the motor 21 and the inverter 22 to form two independent cooling circuits for cooling the motor 21 and the inverter 22 respectively.

[0048] In addition, in order to cool the electrical components of the cruising rotor 29, a cooling system having the same structure as the cooling system 60 can also be provided.

[0049] Figure 3 Indicates Figure 2A The sectional structure of the air flow guiding structure 70 at the reference line CC in. In addition, the central axis in the width direction of the air flow guiding structure 70 is used as the central axis L 70 . The central axis L 70 is parallel to the rotation axis 21a of the VTOL rotor 20. The air flow guiding structure 70 is provided on a part of the boom 18 and forms an accommodating portion for accommodating the radiator 61, and guides the air flow generated by the rotation of one or more blades 23 to the radiator 61 inside the boom 18, and has an upper side structure body 71 and a lower side structure body 72.

[0050] The upper side structure body 71 is a member having a substantially inverted L-shaped cross section that is inserted into the main body portion of the boom 18 and forms an upper side and a left side. The upper side structure body 71 can be formed as a solid, the top end of the upper side is inclined obliquely upward to the right, and a recess 71b extending in the front-rear direction and facing obliquely downward is formed on the lower surface of the upper side. The inner surface (i.e., the right surface) of the left side is formed into a streamline shape that bulges to the left and slightly retracts to the right on a plane orthogonal to the front-rear direction and extends downward from the recess 71b. The upper side of the upper side structure body 71 functions as a beam body 71a that is erected on the upper side of the inlet 70a formed between the upper side structure body 71 and the lower side structure body 72. Thereby, it is possible to resist the bending stress applied to the boom 18 including the air flow guiding structure 70.

[0051] The lower structure 72 is a component having a main body portion inserted into the suspension rod 18 and having a substantially L-shaped cross section forming a lower side and a right side. The lower structure 72 can be formed as a solid, and a concave portion 72b extending obliquely upward and in the front-rear direction is formed on the upper surface of the lower side. The left top end of the lower side is inclined downward, the upper end of the right side is inclined obliquely upward to the right, and the inner surface (i.e., the left surface) of the right side is formed into a streamline shape extending downward from the upper end in a manner of bulging slightly to the left and then slightly retracting to the right on a plane orthogonal to the front-rear direction. The lower side of the lower structure 72 functions as a beam body 72a provided on the lower side of the outlet 70b formed between the upper structure 71 and the lower structure 72. Thereby, it is possible to resist the bending stress applied to the suspension rod 18 including the air flow guiding structure 70.

[0052] By assembling the air flow guiding structure 70 using the upper structure 71 and the lower structure 72 having the above structure, an inlet 70a for sucking air flow is formed on the upper side in the suspension rod 18, and an outlet 70b for ejecting air flow is formed on the lower side. First, the radiator 61 and the fan 61e are overlapped, then the upper structure 71 is fixed to the beam 18c, the upper tank 61c of the radiator 61 is fitted into the concave portion 71b of the upper structure 71, and the bracket provided on the upper tank 61c is fixed to the beam 18c. Then, the lower structure 72 is fixed to the beam 18c, and the lower tank 61d of the radiator 61 is fitted into the concave portion 72b of the lower structure 72, and the bracket provided on the lower tank 61d is fixed to the beam 18c. Thus, the air flow guiding structure 70 is integrally assembled to the main body portion of the suspension rod 18. At this time, the radiator 61 and the fan 61e are supported between the two ribs 18b in the suspension rod 18 using the support member 61f.

[0053] Thereby, between the upper side of the upper structure 71 and the right side of the lower structure 72, the inlet 70a is formed at a position on the side of one surface (suction surface) of the radiator 61, and between the left side of the upper structure 71 and the lower side of the lower structure 72, the outlet 70b is formed at a position on the side of the other surface (exhaust surface) of the radiator 61. And, the radiator 61 is disposed between the inlet 70a and the outlet 70b in the suspension rod 18, and is inclined with respect to the rotation axis 21a (i.e., the central axis L 70 ) of the VTOL rotor 20 so that the suction surface faces the inlet 70a side and the exhaust surface faces the outlet 70b side. And, the two fans 61e are disposed on the exhaust surface side of the radiator 61. In addition, the two fans 61e may also be disposed on the suction surface side of the radiator 61.

[0054] Figure 4AIt represents a structure disposed above the air flow guiding structure 70 of the suspension rod 18. As an example, the air flow guiding structure 70 includes a radiator 61 for cooling the left VTOL rotor 20c, and a suspension rod main body portion disposed between the rotation axes 21a of the two VTOL rotors 20c and 20d (i.e., the rear side of the VTOL rotor 20c). Through the air flow guiding structure 70, the inlet 70a is disposed on the surface of the suspension rod 18 between the rotation axes 21a of the two VTOL rotors 20c and 20d, and is disposed on the surface of the suspension rod 18 below the rotation plane of one or more blades 23 of one of the two VTOL rotors 20c and 20d, in this example, particularly the VTOL rotor 20c, and in the front view, on the side opposite to the rotation direction of one or more blades 23 with respect to the rotation axis 21a (central axis L 70 ) of the VTOL rotor 20c (in this example, to the left), that is, on the opposite side of the rotation direction (in this example, to the right).

[0055] Here, the blade 23 of the VTOL rotor 20 has a blade angle with respect to the rotation plane to generate thrust (refer to Figure 2A ). Therefore, for example, when the blade 23 rotates clockwise as shown in Figure 4A , an air flow is generated in the direction inclined with respect to the downward direction and toward the rotation movement direction of the blade 23, that is, obliquely downward to the left ( Figure 3 the direction of the hollow arrow). Thus, in the air flow guiding structure 70, the inlet 70a is disposed on the right side with respect to the rotation axis 21a (central axis L 70 ) of the VTOL rotor 20c in the front view, so that when the two VTOL rotors 20c and 20d are started, the air flow generated by the rotation of one or more blades 23 of at least one rotor, in this example, particularly the VTOL rotor 20c, can be efficiently guided to the radiator 61 inside the suspension rod 18 through the inlet 70a.

[0056] In addition, as shown in Figure 3 , the top end of the upper edge of the upper structure body 71 of the air flow guiding structure 70 is inclined obliquely upward to the right, and the upper end of the right side edge of the lower structure body 72 is inclined obliquely upward to the right. Therefore, in the air flow guiding structure 70, the top end of the upper edge of the upper structure body 71 faces the upper end of the right side edge of the lower structure body 72. Thus, the inlet 70a is inclined obliquely upward to the right opposite to the rotation direction of the blade 23 of the VTOL rotor 20b ( 70 is to the left in Figure 3 ) with respect to the central axis L. Thus, the air flow generated by the rotation of one or more blades 23 of the VTOL rotor 20b can be efficiently guided to the radiator 61 inside the suspension rod 18 through the inlet 70a.

[0057] Figure 4BThe structure of the lower side of the above-mentioned airflow guide structure 70 is shown. Through the airflow guide structure 70, the outlet 70b is set at a position opposite to the inlet 70a on the lower side of the suspension rod 18. As a result, the airflow introduced through the upper inlet 70a passes through the inside of the suspension rod 18 and is discharged downward from the lower outlet 70b, thereby enabling the airflow to pass through the inside of the suspension rod 18 efficiently.

[0058] In the lower part of the boom 18, in front view, the outlet 70b is in this example relative to the rotation axis 21a (central axis L of the VTOL rotor 20b). 70 ) is provided on the side that follows the rotation direction of one or more blades 23 (the left side in this example), that is, on the side corresponding to the rotation direction (the left side in this example). In other words, the outlet is relative to the rotation axis 21a (central axis L) of the VTOL rotor 20b in the lower part of the boom 18. 70 ) is located on the opposite side of the inlet 70a. As a result, the airflow introduced through the inlet 70a has a longer flow path in the suspension rod 18, contacts the radiator 61 over a long distance and is led out from the outlet 70b, thereby efficiently cooling the radiator 61.

[0059] In addition, if Figure 3 As shown, the left top end of the lower side of the lower structure 72 of the airflow guiding structure 70 is formed to face downward, and the right inner surface of the left side of the upper structure 71 is formed to be streamlined downward. Therefore, in the airflow guiding structure 70, the left top end of the lower side of the lower structure 72 is opposite to the lower end of the left side of the upper structure 71, so that the outlet 70b faces downward more relative to the inlet 70a inclined to the right and upward. As a result, the airflow introduced into the inside of the boom 18 from the inlet 70a to the left and downward is led out from the outlet 70b to a further downward direction, thereby increasing the thrust in the vertical direction applied to the boom 18 (i.e., the body of the aircraft 100). In addition, through the structure of such an airflow guiding structure 70, the output of the fan 61e can also be used as the thrust in the vertical direction applied to the boom 18 (i.e., the body).

[0060] In addition, in the airflow guiding structure 70, the inlet 70a is set at the upper part of the boom 18, but is not limited to this. As long as the airflow generated by the rotation of one or more blades 23 when the VTOL rotor 20 is started can be efficiently introduced into the boom 18, it can be set at any position between the upper part and the side of the boom 18.

[0061] The shape of the boom that can reduce the air resistance applied during cruising will be described.

[0062] Figure 5AThe shape of the boom 18' showing the comparative example. In addition, the boom 18' is a boom arranged on the left side of the fuselage 12, and the boom on the right side is symmetric with it left and right. Here, the shape of the boom 18' when viewed from the side is shown in the upper row, the shape of the boom 18' when viewed from above is shown in the middle row, and the cross-sectional shape of the boom 18' on the reference line AA when viewed from the front is shown in the lower row. The positions where the VTOL rotors 20a, 20b, 20c, 20d are provided, that is, the positions Pa, Pb, Pc, Pd of the motors 21 that accommodate them (rotor positions), are indicated by single-dot dash lines.

[0063] Preferably, in order to smoothly direct the downwash generated by the rotation of the VTOL rotor 20 downward to alleviate air resistance, the boom 18' is shaped as shown in the lower row to have a cross-sectional shape of an airfoil that is smoothly curved on the upper side and tapers from the upper side to the lower side in a front view. However, as shown in the upper row, in a side view, the boom 18' is shaped such that the upper end bulges at the rotor positions Pa, Pb, Pc, Pd of the VTOL rotors 20a, 20b, 20c, 20d, and as shown in the middle row, in a top view, the boom 18' is shaped such that the main body part is arcuately bent to the left with respect to the front end and the rear end and extends in the front-rear direction, resulting in an increase in air resistance during cruising.

[0064] Figure 5B The numerical fluid dynamics analysis results of the air resistance borne by the boom 18' of the comparative example during cruising are shown. Here, the upper row and the lower row respectively show Figure 5A the pressure distributions (static pressures) of the airflows in the vertical cross-sections of the respective reference lines GG and HH shown. In addition, in the pressure distribution in the lower row, the dashed line indicates the cross-sectional shape of the overlapping boom 18' in a top view, and the white horizontal flow line indicates the streamline of the airflow.

[0065] During cruising, the boom 18' is subjected to an airflow from the front to the rear. As a result, on the reference line GG, that is, on the plane that includes the approximate center of the boom 18' in the vertical direction, higher pressure regions (+) are generated on the front side of the front end of the boom 18', slightly in front of and to the left (i.e., the outside) between the rotor positions Pa and Pb, slightly to the rear and to the right (i.e., the inside) between the rotor positions Pb and Pc, slightly to the front and to the right (i.e., the inside) between the rotor positions Pc and Pd, and on the rear side of the rear end, and lower pressure regions are generated on the right (i.e., the inside) between the rotor positions Pa and Pb, on the left (i.e., the outside) between the rotor positions Pb and Pc, and on the left (i.e., the outside) between the rotor positions Pc and Pd. In addition, lower pressure regions (-) are generated on the left and right sides of each of the rotor positions Pa, Pb, Pc, Pd.

[0066] Due to the pressure difference on the left and right sides of such a suspension rod 18', on the reference line HH, which is a plane including the approximate lower end of the suspension rod 18', as shown by the arrow (1), an air flow is generated that flows from left to right (from the outside to the inside) under the suspension rod 18' between the rotor positions Pa and Pb. And as shown by the arrow (2), an air flow is generated that flows from right to left (from the inside to the outside) under the suspension rod 18' on the front side of the rotor position Pc and between the rotor positions Pc and Pd.

[0067] Figure 5C Shows the numerical fluid dynamics analysis results of the air resistance borne by the suspension rod 18' of the comparative example during cruising. Here, it shows Figure 5A The pressure distribution of the air flow (the total pressure, which is the sum of the static pressure and the dynamic pressure) in the front-rear direction profiles of the respective reference lines AA, A'A', BB, CC, DD, EE, and FF shown. In addition, the white line represents the streamline of the air flow. Just behind the rotor position Pa on the reference line AA, the air flow does not exhibit a local pressure gradient and is in an ideal state of flowing backward with a substantially constant pressure distribution around the suspension rod 18'.

[0068] However, between the reference line A'A', that is, between the rotor positions Pa and Pb, the air flow flows from left to right (from the outside to the inside) under the suspension rod 18' as described above, and it wraps around the right side surface of the suspension rod 18', thereby generating a low-pressure region, that is, the eddy current e1, directly to the right of the lower end of the suspension rod 18'. In addition, the air flow flows from left to right (from the outside to the inside) above the suspension rod 18', and it wraps around the right side surface of the suspension rod 18', thereby generating another low-pressure region, that is, the eddy current e2, near the upper right of the suspension rod 18'. These eddy currents e1 and e2 move away from the suspension rod 18' to the right and increase as they move backward, so as to remain just behind the reference line BB, that is, the rotor position Pb.

[0069] Between the reference line CC, that is, between the rotor positions Pb and Pc, the eddy currents e1 and e2 further increase, and the air flow flows from right to left (from the inside to the outside) under the suspension rod 18' as described above, and it wraps around the left side surface of the suspension rod 18', thereby generating another low-pressure region, that is, the eddy current e3, directly to the left of the lower end of the suspension rod 18'.

[0070] Between the reference lines DD and EE, that is, just behind the rotor position Pc and between the rotor positions Pc and Pd, the eddy currents e1 and e3 further increase and move to the left of the suspension rod, and the air flow flows from right to left (from the inside to the outside) under the suspension rod 18' as described above, and it wraps around the left side surface of the suspension rod 18', thereby generating other low-pressure regions, that is, the eddy current e4, directly to the left of the lower end of the suspension rod 18'. In addition, the air flow flows from right to left (from the inside to the outside) above the suspension rod 18', and it wraps around the left side surface of the suspension rod 18', thereby generating another low-pressure region, that is, the eddy current e5, near the upper left of the suspension rod 18'.

[0071] Immediately behind the reference line FF, i.e., directly behind the rotor position Pd, the vortices e1, e3, e4 further increase and move to the left of the boom, and other vortices e6 are generated below the left of the boom 18'.

[0072] When the boom 18' receives the airflow from the front, vortices e1, e2, e3, e4, e5, e6 are generated, thereby suppressing the smooth flow of the airflow and increasing the air resistance borne by the boom 18'.

[0073] Figure 6A Shows the shape of the boom 18 of the present embodiment. In addition, the boom 18 is a boom arranged on the left side of the fuselage 12, and the boom on the right side is symmetrical to it left and right. Here, the shape of the boom 18 when viewed from the side and the cross-sectional shape when viewed from the front on each reference line are shown in the upper row, the shape of the boom 18 when viewed from above is shown in the middle row, and the cross-sectional shape of the boom 18 on the reference line AA when viewed from the front is shown in the lower row. The positions where the VTOL rotors 20a, 20b, 20c, 20d are provided, that is, the positions of the motors 21 that accommodate them (rotor positions Pa, Pb, Pc, Pd), are indicated by dashed lines.

[0074] Similar to the boom 18' of the comparative example, the boom 18 is formed such that in a top view, the main body portion is arcuately bent to the left with respect to the front end and the rear end and extends in the front-rear direction. However, when viewed from the front at all positions in the front-rear direction, it is formed to have an airfoil cross-sectional shape that is smoothly curved on the upper side, tapers from the upper side to the lower side, and is substantially flat on the lower side (i.e., substantially parallel to the front-rear, left-right directions). The boom 18 includes a housing portion 61a 12 、61a 32 、a bottom raised portion 18f, an inclined portion 18h, and a raised portion 18g.

[0075] The housing portion 61a 12 、61a 32 is the rotor portion that houses the radiator 61 of the cooling system 60 and is provided on the boom 18 through the above-described airflow guiding structure 70. In the housing portion 61a 12 、61a 32 , as Figure 6A shown in the lower row or Figure 3 shown, it has an airfoil cross-section that is substantially flat on the lower side. In the boom 18 of the present embodiment, it includes a first housing portion 61a 12 located behind the rotor position Pa 32 and a second housing portion 61a 12 located behind the rotor position Pc. The first housing portion 61a 12is connected to the front wing 14 between the rotor position Pb. The second accommodation part 61a 32 accommodates a radiator 61 for cooling the electrical components of the VTOL rotors 20c and 20d respectively. It should be noted that the boom 18 is in the second accommodation part 61a 32 and is connected to the rear wing 16 between the rotor position Pd.

[0076] The bottom raised part 18f is a boom part with a lower end (i.e., the bottom surface) positioned on the upper side relative to the accommodation part 61a 12 、61a 32 Here, the bottom raised part 18f is at least located at the center of the main body part that is bent relative to the front end and the rear end of the boom 18, that is, between the rotor positions Pb and Pc. Thus, it is possible to avoid the generation of eddies e3, e4, and e6 as shown in Figure 5B (2) during cruising due to the airflow crossing from the inside to the outside below the bending center of the main body part of the boom 18. In addition, the bottom raised part 18f is located on the front side of the main body part that is bent relative to the front end and the rear end of the boom 18, that is, on the front side of the rotor position Pb. Thus, it is possible to avoid the generation of eddy e1 as shown in Figure 5A (1) during cruising due to the airflow crossing from the outside to the inside below the bending center of the main body part of the boom 18.

[0077] In this way, the boom 18 raises the bottom surface of the boom 18 in at least a part other than the accommodation part 61a 12 、61a 32 to reduce the thickness in the vertical direction, thereby ensuring the space 18d for accommodating the radiator 61 and being able to eliminate or suppress the turbulence of the airflow caused by the airflow flowing left and right below the boom 18 during cruising.

[0078] In addition, the bottom raised part 18f is also provided at the rear end of the boom 18, that is, on the front side and the rear side of the rotor position Pd.

[0079] The inclined part 18h is a boom part with a lower end (bottom surface) inclined upward from each accommodation part 61a 12 、61a 32 to the adjacent bottom raised part 18f. In this way, the boom 18 does not form a stepped part between the accommodation part 61a 12 、61a 32 and the adjacent bottom raised part 18f, but slowly raises the bottom raised surface, thereby being able to suppress the turbulence of the airflow flowing below the boom 18.

[0080] The raised part 18g has, at the rotor positions Pa - Pd of the VTOL rotor 20, that is, at the positions of the motors 21 that accommodate them, an upper end relative to other parts, such as the accommodation part 61a12 and 61a 32 A suspension rod portion having a shape that bulges upward. By making the upper end of the bulging portion 18g located above the upper end of the accommodating portion 61a 12 and 61a 32 's upper end is located above, it is possible to ensure a space 18d for accommodating the motor 21 and other electrical components of the VTOL rotor 20 without reducing the lower end of the bulging portion 18g.

[0081] Moreover, the top end of the suspension rod 18 is smoothly curved when viewed from above, and slopes obliquely rearward from the upper side to the lower side when viewed from the side. The rear end of the suspension rod 18 tapers rearward when viewed from above and slopes obliquely rearward from the lower side when viewed from the side. Thereby, it is possible to further suppress the air resistance borne by the suspension rod 18 during cruising.

[0082] In addition, in the suspension rod 18, in the inter-rotor portion between the rotor positions Pa to Pd that does not include the accommodating portion 61a 12 and 61a 32 's inter-rotor portion, in this example, the inter-rotor portion between the rotor positions Pb and Pc, has a width smaller than that of the accommodating portion 61a 12 and 61a 32 for accommodating the radiator 61 and the rotor positions Pa to Pd for accommodating the electrical components of the VTOL rotor 20. By reducing the width of the suspension rod portion with fewer structures, the mass of the suspension rod 18 becomes lighter.

[0083] Figure 6B Shows the numerical fluid dynamics analysis results of the air resistance borne by the suspension rod 18 of the present embodiment and the suspension rod 18' of the comparative example during cruising. Here, in the lower row and the upper row, for the suspension rod 18 and the suspension rod 18' respectively, the pressure distribution (static pressure) of the air flow in the vertical cross-section is shown in the center, the pressure distribution (total pressure) in the front-rear direction cross-section at the reference line AA in the center figure is shown on the left, and the pressure distribution (total pressure) in the front-rear direction cross-section at the reference line BB in the center figure is shown on the right. In addition, the white line represents the streamline of the air flow.

[0084] As used above Figure 5B and Figure 5CAs described, in the analysis result of the suspension rod 18’, a pressure difference is generated on the left and right sides (i.e., the outer and inner sides) slightly in front of the rotor positions Pa and Pb, causing the airflows to flow from bottom to top on the front side of the suspension rod 18’ and then from left to right (from the outer side to the inner side), and then around to the right side. As a result, near the lower end and upper end of the suspension rod 18’, low-pressure areas, i.e., eddies, are generated respectively behind the reference line AA, which is the rear side of the rotor position Pb. In addition, a pressure difference is generated on the left and right sides (outer and inner sides) slightly behind the rotor positions Pb and Pc and between the rotor positions Pc and Pd. Thus, the airflows flow from the center of the suspension rod 18’ from bottom to top on the rear side and then from right to left (from the inner side to the outer side), and then around to the left side. As a result, near the reference line BB, which is the rotor position Pd, a large low-pressure area, i.e., an eddy, is generated in the area from the vicinity of the left side of the suspension rod 18’ to the upper left.

[0085] In contrast, according to the analysis result of the suspension rod 18, by providing the bottom bulge portion 18f in front of the rotor position Pb, the pressure difference between the left and right sides (i.e., the outer and inner sides) between the rotor positions Pa and Pb is alleviated, and the airflows flowing from left to right (from the outer side to the inner side) from bottom to top on the front side of the suspension rod 18 and then around to the right side become weaker. As a result, near the reference line AA, which is the rear side of the rotor position Pb, in the vicinity of the lower end and upper end of the suspension rod 18, the low-pressure areas are generated in a narrow range, i.e., only small eddies are generated. In addition, the bottom bulge portion 18f is provided at the center of the main body of the suspension rod 18, i.e., between the rotor positions Pb and Pc. Thus, the pressure difference between the left and right sides (outer and inner sides) between the rotor positions Pb and Pc and between the rotor positions Pc and Pd is alleviated, and the airflows flowing from the center of the suspension rod 18 to the rear side from bottom to top from right to left (from the inner side to the outer side) and then around to the right side become weaker. As a result, near the reference line BB, which is the rotor position Pd, although a low-pressure area is generated on the left side of the lower end of the suspension rod 18, the generation of the large low-pressure area from the vicinity of the left side to the upper left generated in the suspension rod 18’ is avoided. Therefore, it can be known that the suspension rod 18 can suppress the air resistance borne during cruising.

[0086] In addition, the boom 18' has an airfoil cross-sectional shape that is smoothly curved on the upper side and tapers from the upper side to the lower side. Thus, the airflow separates to the left and right from the upper end of the boom 18', descends along the curved upper surface, separates from the tapered side surface of the boom 18' and expands to the left and right and flows downward. In contrast, the boom 18 has an airfoil cross-sectional shape that is smoothly curved on the upper side, tapers from the upper side to the lower side, and is formed with a substantially flat lower side (i.e., substantially parallel to the front, rear, left, and right directions). Thus, the airflow is the same as that of the boom 18', separates to the left and right from the upper end of the boom 18, descends along the curved upper surface, separates from the tapered side surface of the boom 18 and expands to the left and right and flows downward, and then the airflow bypasses below the flat surface and becomes turbulent. Thus, during vertical takeoff and landing, the air resistance borne by the boom 18 may increase.

[0087] Figure 6C The numerical fluid dynamics analysis results of the air resistance borne by the boom 18 of the present embodiment and the boom 18' of the comparative example during cruising and vertical takeoff and landing are shown. Relative to the boom 18', the air resistance of the boom 18 during vertical takeoff and landing increases by about 10%, and in contrast, the air resistance of the boom 18 during cruising is alleviated by about 60%. Therefore, by adopting the shape of the boom 18 of the present embodiment, the air resistance during cruising can be alleviated with almost no increase in the air resistance during vertical takeoff and landing.

[0088] Figure 7A Examples of the configuration of the boom shape and the housing portion of the radiator 61 are shown. The boom of Example 1 (No. 1) is the boom 18 of the present embodiment, and housing portions 61a 12 、61a 32 are respectively included at the rear sides of the rotor positions Pa and Pc, and a bottom bulge portion 18f is included at the front side of the rotor position Pb, between the rotor positions Pb and Pc, and at the front and rear of the rotor position Pd. Bulge portions 18g are respectively included at the rotor positions Pa to Pd. The boom of Example 2 (No. 2) includes housing portions 61a 12 、61a 22 、61a 31 、61a 32 respectively at the rear sides of the rotor positions Pa and Pb and at the front and rear of the rotor position Pc, a bottom bulge portion 18f is included at the front side of the rotor position Pb and at the front and rear of the rotor position Pd, and bulge portions 18g are respectively included at the rotor positions Pa to Pd. The boom of Example 3 (No. 3) includes housing portions 61a 21 、61a 22 、61a 31 、61a 32, it includes bottom raised portions 18f respectively at the rear side of the rotor position Pa and at the front and rear sides of the rotor position Pd, and includes raised portions 18g at the rotor positions Pa to Pd respectively. The suspension rod of Example 4 (No. 4) includes accommodation portions 61a respectively at the rear side of the rotor position Pa, at the front and rear sides of the rotor position Pb, and at the front and rear sides of the rotor position Pc 12 、61a 21 、61a 22 、61a 31 、61a 32 , it includes a bottom raised portion 18f at the front and rear sides of the rotor position Pd, and includes raised portions 18g at the rotor positions Pa to Pd respectively. The suspension rod of Example 5 (No. 5) includes accommodation portions 61a respectively at the front and rear sides of the rotor position Pb, at the front side of the rotor position Pc, and at the front side of the rotor position Pd 21 、61a 22 、61a 31 、61a 41 , it includes bottom raised portions 18f at the rear side of the rotor position Pa and at the rear side of the rotor position Pc, and includes raised portions 18g at the rotor positions Pa to Pd respectively. The suspension rod of Example 6 (No. 6) includes accommodation portions 61a respectively at the rear side of the rotor position Pa, at the rear side of the rotor position Pb, at the front side of the rotor position Pc, and at the front side of the rotor position Pd 12 、61a 22 、61a 31 、61a 41 , it includes a bottom raised portion 18f at the front side of the rotor position Pb and at the rear side of the rotor position Pc, and includes raised portions 18g at the rotor positions Pa to Pd respectively. The suspension rod of Example 7 (No. 7) is the suspension rod 18' of the above comparative example, and includes accommodation portions 61a respectively at the rear side of the rotor position Pa, at the front and rear sides of the rotor position Pb, at the front and rear sides of the rotor position Pc, and at the front side of the rotor position Pd 12 、61a 21 、61a 22 、61a 31 、61a 32 、61a 41 , it includes raised portions 18g at the rotor positions Pa to Pd respectively and does not include a bottom raised portion 18f. The suspension rod of Example 8 (No. 8) includes accommodation portions 61a respectively at the rear side of the rotor position Pa, at the front and rear sides of the rotor position Pb, at the front and rear sides of the rotor position Pc, and at the front side of the rotor position Pd 12 、61a 21 、61a 22 、61a 31 、61a 32 、61a 41, excluding the bottom raised portions 18f and raised portion 18g. It should be noted that these suspension rods are formed such that the main body portion is arcuately bent laterally relative to the front end and the rear end while extending in the front-rear direction.

[0089] In Figure 7B shows the analysis results based on numerical fluid dynamics of the air resistance borne by each of the suspension rods in Examples 1 to 8 during cruising and vertical takeoff and landing. The horizontal axis is the air resistance borne during cruising, and the vertical axis is the air resistance borne during vertical takeoff and landing. As described above, the suspension rod of Example 7 (the suspension rod 18' of the modified example) has a small air resistance during vertical takeoff and landing but a large air resistance during cruising. The suspension rod of Example 8 does not include the raised portion 18g, and thus, compared with the suspension rod of Example 7, it has a smaller air resistance during vertical takeoff and landing and a larger air resistance during cruising. In contrast, the suspension rods of Examples 1 to 6 include the bottom raised portion 18f, and thus, compared with the suspension rod of Example 7, they have a slightly larger air resistance during vertical takeoff and landing, but the air resistance during cruising is alleviated. Here, for the suspension rods of Examples 1 to 3 that include the bottom raised portion 18f on the front side of the rotor position Pb (or the rear side of the rotor position Pa) and before and after the rotor position Pd, the resistance during cruising is alleviated. Among them, for the suspension rod of Example 1 that includes the bottom raised portion 18f between the rotor positions Pb and Pc, the resistance during cruising is further alleviated. From these results, it can be seen that, like the suspension rod 18 of the present embodiment, it is effective to raise the lower end of the suspension rod between the rotor positions Pb and Pc and on the front side of the rotor position Pb for alleviating the resistance during cruising.

[0090] The aircraft 100 of the present embodiment includes a fuselage 12, a front wing 14 and a rear wing 16 that extend laterally from the fuselage 12 and generate lift during cruising, a suspension rod 18 supported by the front wing 14 and the rear wing 16 and separated from the fuselage 12, and at least one VTOL rotor 20 having one or more blades 23 that are supported on the suspension rod 18 and generate a vertical thrust during takeoff. The suspension rod 18 has a shape in a top view in which the main body portion is bent in a direction away from the fuselage 12 relative to the front end and the rear end and extends in the front-rear direction, and has a cross-sectional shape in a front view that is smoothly curved on the upper side, tapers from the upper side to the lower side, and is substantially flat on the lower side. The suspension rod 18 has a shape in a top view in which the main body portion is bent in a direction away from the fuselage 12 relative to the front end and the rear end and extends in the front-rear direction, whereby during cruising, the airflow crosses below the suspension rod 18 and generates turbulence (especially vortices). However, the suspension rod 18 has a cross-sectional shape in a front view in which the upper end is smoothly curved, tapers from the upper side to the lower side, and is substantially flat on the lower side, whereby the turbulence of the airflow can be eliminated or suppressed. Thus, during cruising, the air resistance borne by the suspension rod can be alleviated, and cruising can be performed with a smaller resistance.

[0091] As described above, the present invention has been explained using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. Those skilled in the art can clearly make various changes or improvements to the above embodiments. In addition, according to the description of the protection scope of the present invention, it is obvious that the embodiments with such changes or improvements are also included in the technical scope of the present invention.

[0092] It should be noted that the execution order of each process such as actions, processes, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings can be implemented in any order as long as it is not specifically stated as "before", "preceding", etc., and the output of the previous process is not used in the subsequent process. Regarding the action flow in the claims, the specification, and the drawings, even if it is described using "first," "next," etc. for convenience, it does not mean that it must be implemented in this order.

[0093] [Description of Reference Numerals]

[0094] 12: fuselage; 14: front wing; 14a: elevator; 16: rear wing; 16a: aileron; 16b: vertical tail; 18, 18’: boom; 18a: skin; 18b: rib; 18c: beam; 18d, 18e: space; 18f: bottom bulge; 18g: bulge; 18h: inclined part; 20(20a, 20b, 20c, 20d): VTOL rotor; 21: motor; 21a: rotating shaft; 22: inverter; 23: blade; 29: cruise rotor; 32: hanger; 54: duct; 60: cooling system; 61: radiator; 61a: pipe; 61a 12 、61a 21 、61a 22 、61a 31 、61a 32 、61a 41 : accommodation part; 61b: fin; 61c: upper tank; 61d: lower tank; 61e: fan; 61f: support member; 62: pump; 63: coolant tank; 64, 65: piping; 70: air flow guiding structure; 70a: inlet; 70b: outlet; 71: upper structure; 71a: beam body; 71b: recess; 72: lower structure; 72a: beam body; 72b: recess; 100: aircraft; L, L 70 : central axis; Pa, Pb, Pc, Pd: rotor positions; e1, e2, e3, e4, e5, e6: vortices.

Claims

1. An aircraft, comprising: A fuselage; A wing-fuselage that extends laterally from the fuselage and generates lift during cruising; A pylon that is supported by the wing-fuselage separately from the fuselage; and At least one rotor that is supported on the pylon and has one or more blades that generate vertical thrust during takeoff and landing, When viewed from above, the pylon has a shape in which the main body portion bends in a direction away from the fuselage with respect to the front end and the rear end and extends in the front-rear direction, and when viewed from the front, the pylon has a cross-sectional shape that is smoothly curved on the upper side, tapers from the upper side to the lower side, and is substantially flat on the lower side.

2. The aircraft according to claim 1, wherein The pylon houses a rotating device and a radiator and has a bottom bulge portion, and with respect to the housing portion that houses the radiator, the lower end is located on the upper side. The rotating device rotates the one or more blades of the at least one rotor, and the radiator cools the rotating device.

3. The aircraft according to claim 2, wherein The bottom bulge portion is at least located at the center of the main body portion of the pylon that bends with respect to the front end and the rear end.

4. The aircraft according to claim 2 or 3, wherein The bottom bulge portion is at least located on the front side of the main body portion of the pylon that bends with respect to the front end and the rear end.

5. The aircraft according to any one of claims 2 to 4, wherein The pylon has a shape in which the upper end of the rotor position that houses the rotating device is located on the upper side with respect to the housing portion.

6. The aircraft according to any one of claims 2 to 5, wherein The pylon houses the rotating devices of four rotors at a first rotor position, a second rotor position, a third rotor position, and a fourth rotor position arranged in order from the front to the rear, The housing portion includes a first housing portion located at the rear side of the first rotor position and a second housing portion located at the rear side of the third rotor position.

7. The aircraft according to claim 6, wherein The bottom bulge portion is located between the second rotor position and the third rotor position.

8. The aircraft according to claim 6 or 7, wherein The bottom bulge portion is located on the front side of the second rotor position.

9. The aircraft according to any one of claims 6 to 8, wherein The pylon has a width smaller than that of the housing portion in the inter-rotor portion between the first rotor position and the fourth rotor position that does not include the housing portion.

10. The aircraft according to any one of claims 2 to 9, wherein The lower end of the pylon is inclined from the housing portion to the bottom bulge portion.

11. The aircraft according to any one of claims 1 to 10, wherein The pylon has a shape in which the front end is smoothly curved and the rear end tapers.

12. The aircraft according to any one of claims 1 to 11, wherein, It further includes a cruising rotor that is provided at the rear end of the fuselage and has one or more blades that generate thrust during cruising.

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