A military transport aircraft

Abstract

The application belongs to the field of aircraft design, and particularly relates to a military transport aircraft. The military transport aircraft comprises a fuselage (1), a ring-shaped wing (2), an engine (3), a vertical tail (4), a canard (5), a landing gear (6) and a rear cargo door (7). The ring-shaped wing (2) extends upwards and upwards from the middle floor of the fuselage, and is connected with the vertical tail (4). The fuselage is surrounded by the ring-shaped wing (2) by 360 degrees. The engine nozzle is shielded from below and from the side by the ring-shaped wing (2). The main landing gear strut is connected to the wing and can be placed in the wing after being retracted. The application improves the cruising efficiency of the military transport aircraft, reduces the structural weight, improves the airport and take-off and landing adaptability, effectively shields and protects the fuselage and the engine, and comprehensively enhances the use efficiency of the transport aircraft.

Description

A military transport aircraft Technical Field

[0001] This application pertains to the field of aircraft design, and in particular relates to a military transport aircraft. Background Technology

[0002] Existing military transport aircraft, such as the American C-17 and C-5, the Russian Il-76, and the European A400M, all employ aerodynamic layouts including a cylindrical fuselage, a high-sweep trapezoidal wing, wing-mounted engines, a multi-wheel, multi-strut tricycle landing gear, a large rear fuselage hatch, and a T-tail. The most significant advantages of these aircraft are their mature technology, short development cycles, and ability to generally meet the needs of transporting combat personnel and bulk / contained supplies. However, many shortcomings still remain.

[0003] First, swept trapezoidal wings cannot have too large an aspect ratio due to factors such as structural weight and wing stiffness, which prevents further reduction of induced drag and further improvement of aircraft aerodynamic efficiency, directly restricting the transport efficiency of military transport aircraft.

[0004] Second, the high-wing design cannot protect the fuselage during emergency landings, and the fuselage is underwater during water landings, making emergency evacuation difficult and posing a significant safety hazard during personnel transport.

[0005] Third, the high wing position means the landing gear can only be mounted on the fuselage, which requires a large bulge to house the landing gear. The fuselage frame needs additional reinforcement, and the bulge adds extra weight and drag. It also limits the main wheel track, making it difficult to ensure stability during takeoff, especially on unpaved runways in field airports, which is detrimental to takeoff safety.

[0006] Fourth, wing-mounted engines are prone to ingesting debris such as gravel from the airport runway during takeoff and landing, and have low survivability when attacked by enemy ground fire during ascent and descent.

[0007] Fifth, the high-mounted horizontal stabilizer of the T-shaped tail fin requires vertical stabilizer support, and the strength and rigidity of the vertical stabilizer need to be further enhanced. Summary of the Invention

[0008] In order to solve at least one of the above-mentioned technical problems, this application designs a military transport aircraft to improve cruise efficiency, reduce structural weight, increase takeoff and landing adaptability, enhance battlefield survivability, and thus improve the overall operational effectiveness of the military transport aircraft.

[0009] The military transport aircraft provided in this application mainly includes a fuselage, which includes a forward fuselage section, a mid-fuselage section and a rear fuselage section. The military transport aircraft also includes a ring wing, an engine, a vertical tail, a canard wing, a landing gear and a rear cargo door.

[0010] The annular wing includes a wing root section, a wing midsection, and a wingtip. The wing root section passes through the floor of the fuselage midsection, bends outward and backward, and extends to the wing midsection located on the side of the fuselage midsection. The wing midsection extends upward and backward to the wingtip located above the rear section of the fuselage. The wingtip on both sides of the aircraft extends inward and towards each other at the rear section of the fuselage and intersects with the wingtip of the vertical tail fin located above the rear section of the fuselage.

[0011] The engines are located on both sides of the rear section of the fuselage, the canards are located on the upper sides of the front section of the fuselage, the landing gear includes a nose landing gear located on the belly of the front section of the fuselage and a main landing gear located at the bottom of the wing root section, and the rear cargo door is located on the belly of the rear section of the fuselage.

[0012] Preferably, the wingtip of the vertical tail is fixedly connected to the lower surface of the wingtip of the annular wing.

[0013] Preferably, the engine is supported by a bracket on the upper middle part of the rear section of the fuselage, and the engines on the left and right sides are symmetrical with respect to the fuselage. The engines are shielded by the middle section of the annular wing on both sides of the fuselage.

[0014] Preferably, the engine's air intake is located above the trailing edge of the wing root section of the annular wing to create a suction effect on the boundary layer of the upper wing surface.

[0015] Preferably, the annular wing on either side of the fuselage unfolds into a trapezoidal shape along the horizontal plane, with both the leading and trailing edges of the wing swept back, a long root chord length, a short tip chord length, and a tip-to-root ratio between 0.2 and 0.5.

[0016] Preferably, the aspect ratio of the annular wing on either side of the fuselage is not less than 15, and the aspect ratio is defined as the ratio of the square of the span of the trapezoidal wing when unfolded along the horizontal plane to the area of ​​the trapezoidal wing.

[0017] Preferably, the spanwise dimension of the aircraft's annular wing is smaller than the fuselage length, and the ratio of the spanwise dimension of the annular wing to the fuselage length is not higher than 0.5.

[0018] Preferably, the main landing gear is connected to the annular wing via a main landing gear strut. After takeoff, the left and right main landing gear wheels rotate inward by 90° and are then retracted into the annular wing.

[0019] This application improves the cruise efficiency of military transport aircraft, reduces structural weight, enhances airport and takeoff / landing adaptability, and effectively shields and protects the fuselage and engines, thus comprehensively enhancing the operational effectiveness of the transport aircraft. Attached Figure Description

[0020] Figure 1 is a three-dimensional schematic diagram of the aerodynamic layout of a preferred embodiment of the military transport aircraft of this application.

[0021] Figure 2 is a side view of the aerodynamic layout of a military transport aircraft according to the embodiment shown in Figure 1 of this application.

[0022] Figure 3 is a front view of the aerodynamic layout of a military transport aircraft according to the embodiment shown in Figure 1 of this application.

[0023] Figure 4 is a top view of the aerodynamic layout of a military transport aircraft according to the embodiment shown in Figure 1 of this application.

[0024] Among them, 1-fuselage, 11-forward section of fuselage, 12-mid section of fuselage, 13-rear section of fuselage, 2-ring wing, 21-wing root section, 22-mid section of wing, 23-wingtip, 24-leading edge of wing, 25-trailing edge of wing, 3-engine, 31-support bracket, 4-vertical tail, 5-canard, 6-landing gear, 61-nose landing gear, 62-main landing gear, 7-rear cargo door. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0026] This application provides a military transport aircraft, as shown in Figures 1-4, including a fuselage 1, which includes a forward fuselage section 11, a mid-fuselage section 12, and a rear fuselage section 13. The military transport aircraft adopts a canard annular wing layout, and therefore also includes an annular wing 2, an engine 3, a vertical tail 4, a canard wing 5, a landing gear 6, and a rear cargo door 7.

[0027] The annular wing 2 includes a wing root section 21, a wing mid section 22, and a wingtip 23. The wing root section 21 passes through the floor of the fuselage mid section 12, bends outward and backward, and extends to the wing mid section 22 located on the side of the fuselage mid section 12. The wing mid section 22 extends upward and backward to the wingtip 23 located above the rear section 23 of the fuselage. The wingtip 23 on both sides of the aircraft extend inward towards each other after the rear section 23 of the fuselage, and intersects with the wingtip portion of the vertical tail 4 located above the rear section 13 of the fuselage.

[0028] The engine 3 is located on both sides of the rear section 13 of the fuselage, the canard 5 is located on both sides of the upper part of the front section 11 of the fuselage, the landing gear 6 includes the nose landing gear 61 located on the belly of the front section 11 of the fuselage and the main landing gear 62 located at the bottom of the wing root section 21, and the rear cargo door 7 is located on the belly of the rear section 23 of the fuselage.

[0029] This application uses a ring wing 2 to surround and protect the fuselage 360°, which can effectively mitigate impacts from below or the side during emergency landings, protecting the safety of personnel or cargo inside the fuselage. The canard wing 5 is located slightly above the forward section 11 of the fuselage, ensuring that its longitudinal position is above the root section 21 of the ring wing.

[0030] In some alternative embodiments, the wingtip of the vertical tail 4 is fixedly connected to the lower surface of the wingtip 23 of the annular wing 2, serving to resist pressure and bending.

[0031] In some alternative embodiments, the engine 3 is supported by a bracket 31 on the upper middle part of the rear section 13 of the fuselage, and the left and right engines 3 are symmetrical with respect to the fuselage. The engines 3 are shielded on both sides of the fuselage by the middle section 22 of the annular wing 2.

[0032] In this embodiment, when viewed from the ground upwards, the engine 3 is shielded by the wing root section 21, and when viewed from the side, the engine 3 is shielded by the wing midsection 22. This design not only prevents the engine from ingesting foreign objects on the runway during takeoff and landing, but also reduces the probability of being detected, identified, tracked, and attacked by enemy ground air defense forces by shielding the strong infrared signals radiated from the engine exhaust nozzle during missions. At the same time, it can effectively protect the engine even if attacked by the enemy, greatly improving the overall survivability of the aircraft.

[0033] In some alternative embodiments, the air intake of the engine 3 is located above the trailing edge of the root section 21 of the annular wing 2 to create a suction effect on the boundary layer of the upper wing surface.

[0034] As shown in Figure 4, the engine 3 is supported by bracket 31 on the upper part of the rear fuselage section 13. The engine's air intake is located just above the trailing edge of the wing root section 21. By utilizing the suction effect of the engine on the boundary layer on the wing surface during operation, it can increase lift and reduce drag, thereby improving the maximum lift coefficient of the aircraft during takeoff and landing and the aerodynamic efficiency during cruise.

[0035] In some alternative embodiments, the annular wing 2 on either side of the fuselage unfolds into a trapezoidal shape along the horizontal plane, with both the leading edge 24 and the trailing edge 25 of the wing swept back, the root chord length being long, the tip chord length being short, and the tip-to-root ratio being between 0.2 and 0.5.

[0036] In some alternative embodiments, the aspect ratio of the annular wing 2 on either side of the fuselage is not less than 15, and the aspect ratio is defined as the ratio of the square of the span of the trapezoidal wing when unfolded along the horizontal plane to the area of ​​the trapezoidal wing.

[0037] In this embodiment, the annular wing layout allows the aircraft's aspect ratio to be designed to be above 15, which is much higher than that of existing military transport aircraft. This can significantly reduce induced drag during flight, improve cruise efficiency, and avoid incurring additional structural weight costs.

[0038] In some alternative implementations, the spanwise dimension of the annular wing 2 of the aircraft is smaller than the fuselage length, and the ratio of the spanwise dimension of the annular wing 2 to the fuselage length is not higher than 0.5.

[0039] In this embodiment, the aircraft's span is much smaller than its fuselage length, with a span / length ratio of approximately 0.5, which is much smaller than that of the C-17 (0.98), C-5 (0.90), Il-76 (1.08), and A400M (0.94). This means that for transport aircraft of the same size, this layout can significantly reduce the aircraft's span, effectively saving space when parked in airport hangars or on the apron, and improving airport utilization.

[0040] In some alternative embodiments, the main landing gear 62 is connected to the annular wing 2 via a main landing gear strut. After the aircraft takes off, the left and right main wheels of the main landing gear 62 rotate inward by 90° and are then retracted into the annular wing 2.

[0041] The main landing gear struts of this application are connected to the wings, which significantly increases the main wheel track compared to existing military transport aircraft, improving stability during takeoff and landing and effectively enhancing adaptability to dirt and gravel runways at field airports. After takeoff, the left and right main wheels rotate inward 90° and retract into the wings, eliminating the need for additional landing gear bulges and reducing weight and drag.

[0042] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A military transport aircraft, comprising a fuselage (1), the fuselage including a forward fuselage section (11), a mid-fuselage section (12), and a rear fuselage section (13), characterized in that, The military transport aircraft also includes a ring wing (2), an engine (3), a vertical tail (4), a canard (5), landing gear (6), and a rear cargo door (7); wherein, the ring wing (2) includes a wing root section (21), a wing midsection (22), and a wingtip (23). The wing root section (21) passes through the floor of the fuselage midsection (12), bends outward and backward, and extends to the wing midsection (22) located on the side of the fuselage midsection (12). The wing midsection (22) extends upward and backward to the wingtip (23) located above the rear fuselage midsection (13). The wingtip (23) on both sides of the aircraft extend inward towards each other after the rear fuselage midsection (13), and intersect with the wingtip portion of the vertical tail (4) located above the rear fuselage midsection (13); the engine (3) is located on the rear fuselage midsection. (13) On both sides, the canard (5) is located on the upper side of the front section (11) of the fuselage. The landing gear (6) includes the nose landing gear (61) located on the belly of the front section (11) of the fuselage and the main landing gear (62) located at the bottom of the wing root section (21). The rear cargo door (7) is located on the belly of the rear section (13) of the fuselage. The engine (3) is supported by the bracket (31) on the upper middle part of the rear section (13). The engines (3) on the left and right sides are symmetrical with respect to the fuselage. The engines (3) are blocked on both sides of the fuselage by the middle section (22) of the wing of the annular wing (2). The annular wing (2) on either side of the fuselage unfolds into a trapezoidal shape along the horizontal plane. The leading edge and trailing edge of the wing are swept back. The wing root chord is long and the wing tip chord is short. The tip-to-root ratio is between 0.2 and 0.

5.

2. The military transport aircraft as described in claim 1, characterized in that, The wingtip of the vertical tail (4) is fixedly connected to the lower surface of the wingtip (23) of the annular wing (2).

3. The military transport aircraft as described in claim 1, characterized in that, The air intake of the engine (3) is located above the trailing edge of the root section (21) of the annular wing (2) to create a suction effect on the boundary layer of the upper wing surface.

4. The military transport aircraft as described in claim 1, characterized in that, The aspect ratio of the annular wing (2) on either side of the fuselage is not less than 15. The aspect ratio is defined as the ratio of the square of the span of the trapezoidal wing after unfolding along the horizontal plane to the area of ​​the trapezoidal wing.

5. The military transport aircraft as described in claim 4, characterized in that, The spanwise dimension of the aircraft's annular wing (2) is smaller than the fuselage length, and the ratio of the spanwise dimension of the annular wing (2) to the fuselage length is not higher than 0.

5.

6. The military transport aircraft as described in claim 1, characterized in that, The main landing gear (62) is connected to the annular wing (2) via the main landing gear strut. After the aircraft takes off, the left and right main wheels of the main landing gear (62) rotate inward by 90° and are then stored in the annular wing (2).

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