Aerodynamic configuration of a blended wing body unmanned aerial vehicle
By optimizing the aerodynamic design of the blended wing-body UAV, and by adopting a V-tail and specific airfoil parameters, the stability and lift-to-drag ratio issues of the UAV in cruise mode were resolved, achieving efficient flight and improved stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI UNIV
- Filing Date
- 2025-01-14
- Publication Date
- 2026-06-23
AI Technical Summary
How to develop an aerodynamic shape for a blended wing-body UAV that fully leverages its high lift-to-drag ratio and improves its stability during cruise?
It employs a specific design of V-tail, control surfaces, inner and outer wings, combined with optimized airfoil and geometry parameters, including sweep angle design of the leading and trailing edges, to enhance lift distribution and reduce drag. The aerodynamic shape is optimized through computational fluid dynamics and aerodynamics, and the addition of a V-tail improves flight stability.
It achieves higher aerodynamic efficiency, lower fuel consumption, greater internal space utilization, and lower noise levels, while improving flight stability and lift-to-drag ratio and optimizing internal space utilization.
Smart Images
Figure CN119821716B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high lift-to-drag ratio flight technology for low-altitude economic unmanned aerial vehicles (UAVs), and particularly to the aerodynamic shape of a blended wing-body UAV. Background Technology
[0002] Since the invention of the airplane, reducing drag, improving flight performance, and lowering structural weight have been ongoing research directions for the aviation industry. The blended wing-body (BWB) aircraft design was first proposed by NASA's Langley Research Center in the 1990s. Due to its highly integrated layout, its wetted area is much smaller than that of traditional layout aircraft, significantly reducing drag and improving the lift-to-drag ratio, thus resulting in better aerodynamic characteristics. Furthermore, BWB aircraft possess significant potential advantages in flight performance, structural weight, safety, environmental friendliness, and comfort, attracting widespread attention and in-depth research from aircraft manufacturers and researchers both domestically and internationally. Countries with developed aviation industries, such as the United States, Europe, and Russia, have successively invested substantial resources in the research of blended wing-body aircraft and achieved significant progress.
[0003] Due to its high lift-to-drag ratio, the BWB drone is ideally suited as the preferred choice for transport and long-endurance missions. Therefore, developing a BWB drone has very clear application scenarios and requirements in both military and civilian fields. In military applications, it can undertake tasks such as reconnaissance, transport, and bombing; in civilian applications, it can handle aerial photography, surveying, and delivery services.
[0004] The aerodynamic features of the BWB drone are its smoothly transitioned wings and fuselage. Unlike conventionally laid-out aircraft, its fuselage aerodynamic shape is also formed by airfoil sweep, thus generating greater lift on its fuselage to achieve a higher lift-to-drag ratio and higher aerodynamic efficiency than conventionally laid-out aircraft.
[0005] Developing an aerodynamic shape for a blended wing-body UAV that fully leverages its high lift-to-drag ratio and improves its stability during cruise has become a technical challenge that urgently needs to be addressed by those skilled in the art. Summary of the Invention
[0006] The purpose of this invention is to provide an aerodynamic shape for a blended wing-body unmanned aerial vehicle (UAV) to solve the problems listed in the background art.
[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0008] The present invention discloses an aerodynamic shape of a blended wing-body unmanned aerial vehicle (UAV), comprising a wing-body portion, a V-tail fin mounted on the rear end of the upper surface of the wing-body portion, an engine mounted between the opposing surfaces of the V-tail fin, and control surfaces mounted on both the wing-body portion and the V-tail fin; and a landing gear mounted on the lower surface of the wing-body portion.
[0009] The wing body includes an inner wing and an outer wing, the inner wing and the outer wing are arranged symmetrically, and the edge of the outer wing is fitted with a wingtip;
[0010] The leading edge sweep angle of the wing-body section is 20°, and the trailing edge sweep angle of the wing-body section is 17°.
[0011] Preferably, the wing body is generated using three cross sections and three guide lines, with the midpoint of the leading edge as the coordinate origin (0, 0, 0) mm, and the wingtip is extended from the outer wing to a closed point (1520, 265, 2187.5) mm.
[0012] Preferably, the three sections of the wing-body portion are located at spanwise 0, 1250, and 2062.5 mm, respectively;
[0013] The airfoil section located at 0mm span has an airfoil section of MH91, scaled proportionally to a chord length of 2000mm, with a blunt trailing edge of 10mm height. The leading edge point of the airfoil section is the origin (0, 0, 0)mm.
[0014] The airfoil section located at 1250mm span is ONERAOA209, proportionally scaled down to 450mm chord length, with the leading edge point of the airfoil being (950, 100, 1250)mm. The airfoil is twisted by -1° around the Z-axis at 1 / 4 chord length and by -4° around the X-axis.
[0015] The airfoil section located at 2062.5 mm span is a self-designed airfoil, scaled proportionally to a chord length of 250 mm. The leading edge point of the airfoil is (1250, 190, 2062.5) mm. The airfoil is twisted 2° around the Z-axis at 1 / 4 chord length and -21° around the X-axis.
[0016] Preferably, the overall geometric parameters of the wing-body section include a wingspan of b = 4.375 m and a wing area of S = 2.08 m². 2 Aspect ratio A = 9.2; Flange root chord length C r = 0.758m; mean aerodynamic chord length C a =0.546m; root-to-tip ratio λ = 0.33; 1 / 4 chord sweep angle Λ = 17°.
[0017] Preferably, the V-shaped tail fin is formed using two cross sections, and the wingtip of the V-shaped tail fin is extended by 60mm from the main body of the V-shaped tail fin to form a closed shape;
[0018] The V-tail has a vertical tail height of 700mm, a root chord length of 492mm, a leading edge sweep angle of 28°, and a root-to-tip ratio of 0.3.
[0019] Preferably, the two sections of the V-shaped tail fin are located at 0 and 640 mm span, respectively;
[0020] The cross-sectional airfoil of the V-tail located at 0mm span is NACA0008, scaled proportionally to a chord length of 492mm;
[0021] The V-tail fin located at a span of 640 mm has a cross-sectional airfoil of NACA0008, scaled proportionally to a chord length of 147.6 mm, and the leading edge point of the V-tail fin is (300, 640, 0).
[0022] The V-shaped tail fin was first rotated -2° around the Y-axis, then rotated 41.7° around the X-axis, and finally translated to the coordinates (1300, 0, 300) mm of the leading edge point of the wing root of the V-shaped tail fin.
[0023] Preferably, the V-tail geometry parameters include: horizontal projected tail volume of 0.7; vertical projected tail volume of 0.11; wingspan b = 0.64 m; wing area S = 0.2045; and wing root chord C. r =0.492m; root-to-tip ratio λ =0.3; V-tail leading edge sweep angle Λ =28°; angle θ between V-tail wing surface and V-tail symmetry plane =41.7°.
[0024] Preferably, the landing gear consists of a front wheel and two main wheels. The front wheel controls the direction of the plane when it is sliding on the ground, and the main wheels bear the main weight and control the braking.
[0025] Preferably, the control surface includes an elevator, a rudder, and an aileron. The elevator is located in the middle of the trailing edge, the elevator is 300 mm wide, the elevator is located at the leading edge at X = 1600 mm, the maximum upward deflection angle of the elevator is 30°, and the maximum downward deflection angle of the elevator is 20°.
[0026] The rudder is located on the V-shaped tail fin, between 192mm and 640mm in span of the V-shaped tail fin. The width of the rudder is 0.3 times the chord length of the corresponding section, and the maximum deflection angle of the rudder is ±20°.
[0027] The aileron is located on the trailing edge of the outer wing, between 1100mm and 1800mm along the wing span of the wing body portion. The width of one end of the aileron is 0.2 times the chord length of the corresponding section, and the width of the other end of the aileron is 0.25 times the chord length of the corresponding section.
[0028] The maximum upward deflection angle of the aileron is 25°, and the maximum downward deflection angle of the aileron is 20°.
[0029] Compared with the prior art, the beneficial technical effects of the present invention are as follows:
[0030] This invention discloses an aerodynamic shape for a blended wing-body UAV, which has significant technical advantages over conventional layout aircraft. It boasts higher aerodynamic efficiency, lower fuel consumption, greater internal space utilization, and lower noise levels. Based on its higher aerodynamic efficiency, the design fully leverages its characteristics to achieve a larger lift-to-drag ratio and optimizes internal space to achieve a larger payload volume. Furthermore, the addition of a V-tail to the wing-body design enhances flight stability. Attached Figure Description
[0031] The present invention will be further described below with reference to the accompanying drawings.
[0032] Figure 1 This is a top view schematic diagram of the aerodynamic shape of a blended wing-body UAV according to the present invention. Figure 1 ;
[0033] Figure 2 This is a top view schematic diagram of the aerodynamic shape of a blended wing-body UAV according to the present invention. Figure 2 ;
[0034] Figure 3 This is a side view schematic diagram of the aerodynamic shape of a blended wing-body UAV according to the present invention;
[0035] Figure 4 This describes the shape and position of the wing-body airfoil in this invention.
[0036] Explanation of reference numerals in the attached diagram: 1. Wing-body; 2. V-tail; 3. Control surfaces; 4. Engine; 5. Landing gear; 6. Inner wing; 7. Outer wing; 8. Wingtip; 9. Leading edge; 10. Trailing edge; 11. Elevator; 12. Rudder; 13. Aileron; 14. Nose wheel; 15. Main wheel. Detailed Implementation
[0037] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0038] like Figure 1-4 As shown, the aerodynamic shape of a blended wing-body UAV includes a wing-body portion 1, a V-tail 2 mounted on the rear end of the upper surface of the wing-body portion 1, an engine 4 mounted between the opposite surfaces of the V-tail 2, and control surfaces 3 mounted on both the wing-body portion 1 and the V-tail 2; a landing gear 5 is mounted on the lower surface of the wing-body portion 1.
[0039] The wing-body portion 1 includes an inner wing 6 and an outer wing 7, the inner wing 6 and the outer wing 7 are arranged symmetrically, and the outer wing 7 has a wingtip 8 installed on its edge;
[0040] The leading edge 9 of the wing body section 1 has a sweep angle of 20°, and the trailing edge 10 of the wing body section 1 has a sweep angle of 17°.
[0041] Specifically, the wing-body section 1 is generated using three cross sections and three guide lines, with the midpoint of the leading edge 9 as the coordinate origin (0, 0, 0) mm. The wingtip 8 is extended from the outer wing 7 to the point (1520, 265, 2187.5) mm to form a closed structure. The fuselage symmetry plane is 1972 mm long and 303 mm thick, with no obvious winglets. The entire wing-body section gradually flips upwards.
[0042] like Figure 4 As shown, the three sections of the wing-body section 1 are located at spanwise 0, 1250, and 2062.5 mm, respectively;
[0043] The airfoil section 1 located at 0mm span is MH91, scaled proportionally to a chord length of 2000mm, with a blunt tail edge 10mm high, so that the actual fuselage length is 1972mm. The leading edge point of the airfoil section 1 is the origin 0,0,0mm.
[0044] The airfoil section 1 located at 1250mm span is ONERA OA209, proportionally scaled down to 450mm chord length, with the leading edge point of the airfoil being (950, 100, 1250)mm. The airfoil is twisted by -1° around the Z-axis at 1 / 4 chord length and by -4° around the X-axis.
[0045] The airfoil section 1 located at 2062.5 mm span is a self-designed airfoil, scaled proportionally to a chord length of 250 mm. The leading edge point of the airfoil is (1250, 190, 2062.5) mm. The airfoil is twisted 2° around the Z-axis at 1 / 4 chord length and -21° around the X-axis.
[0046] Specifically, the overall geometric parameters of the wing-body section 1 include a wingspan of b = 4.375 m and a wing area of S = 2.08 m². 2 Aspect ratio A = 9.2; Flange root chord length C r = 0.758m; mean aerodynamic chord length Ca =0.546m; root-to-tip ratio λ = 0.33; 1 / 4 chord sweep angle Λ = 17°.
[0047] Specifically, the V-shaped tail fin 2 is formed using two cross sections, and the wingtip of the V-shaped tail fin 2 is extended by 60mm from the main body of the V-shaped tail fin 2 to form a closed structure.
[0048] The V-tail wing 2 has a vertical tail height of 700mm, a root chord length of 492mm, a leading edge sweep angle of 28°, and a root-to-tip ratio of 0.3.
[0049] Specifically, the two sections of the V-shaped tail fin 2 are located at 0 and 640 mm span, respectively;
[0050] The cross-sectional airfoil of the V-tail fin 2 located at 0mm span is NACA0008, scaled proportionally to a chord length of 492mm;
[0051] The V-tail wing 2 located at a span of 640 mm has a cross-sectional airfoil of NACA0008, scaled proportionally to a chord length of 147.6 mm, and the leading edge point of the airfoil of the V-tail wing 2 is (300, 640, 0).
[0052] The V-shaped tail fin 2 is first rotated -2° around the Y-axis, then rotated 41.7° around the X-axis, and finally translated to the coordinates (1300, 0, 300) mm of the leading edge point of the wing root of the V-shaped tail fin 2.
[0053] Specifically, the geometric parameters of the V-tail fin 2 include: horizontal projected tail volume of 0.7; vertical projected tail volume of 0.11; wingspan b = 0.64 m; wing area S = 0.2045; and wing root chord C. r =0.492m; root-to-tip ratio λ =0.3; V-tail leading edge sweep angle Λ =28°; angle θ between V-tail wing surface and V-tail symmetry plane =41.7°.
[0054] Specifically, the landing gear 5 consists of a front wheel 14 and two main wheels 15. The front wheel 14 controls the direction of the aircraft when gliding on the ground, and the main wheels 15 bear the main weight and control the braking. The design weight of the UAV is 100kg, and the center of gravity is set at (870,0,0)mm. The design ensures that the main wheels bear 90% of the weight when stationary. The design limit of the ground contact angle is greater than or equal to 13.5°. The design angle between the perpendicular line from the center of gravity to the line connecting a main wheel and the front wheel and the ground is greater than or equal to 50°. The coordinates of the contact point between the front wheel and the ground are (240,-250,0)mm, and the coordinates of the contact point between the main landing gear wheels and the ground are (940,-240,300)mm.
[0055] Specifically, the engine is planned to be a turbojet engine, mounted with a back support. The outer casing needs to ensure sufficient internal space. The initial plan is to adopt a power scheme with a thrust-to-weight ratio of 0.3. Each engine needs to generate about 15 kg of power, and the corresponding engine size is about 100 mm in diameter and 250 mm in length. In order to make the air intake perpendicular to the flow on the surface of the fuselage, the installation angle between the pod and the X-axis is 5°. The coordinates of the center point of the engine air intake are (1305.23, 189.77, 200) mm.
[0056] Specifically, the control surface portion 3 includes an elevator 11, a rudder 12, and an aileron 13. The elevator 11 is located in the middle of the trailing edge 10. The elevator 11 is 300mm wide. The elevator 11 is located at X=1600mm of the leading edge 9. The maximum upward deflection angle of the elevator 11 is 30°, and the maximum downward deflection angle of the elevator 11 is 20°.
[0057] The rudder 12 is located on the V-shaped tail fin 2, between 192mm and 640mm in span of the V-shaped tail fin 2. The width of the rudder 12 is 0.3 times the chord length of the corresponding section, and the maximum deflection angle of the rudder 12 is ±20°.
[0058] The aileron 13 is located on the trailing edge 10 of the outer wing 7, between 1100mm and 1800mm along the wing span of the wing body portion 1. The width of one end of the aileron 13 is 0.2 times the chord length of the corresponding section, and the width of the other end of the aileron 13 is 0.25 times the chord length of the corresponding section.
[0059] The maximum upward deflection angle of the aileron 13 is 25°, and the maximum downward deflection angle of the aileron 13 is 20°.
[0060] The core research and development idea of this invention is to improve the stability of cruise while achieving a high lift-to-drag ratio. Its theoretical basis is computational fluid dynamics and aerodynamics. To achieve this core research and development goal, the design of this blended wing-body UAV requires detailed optimization in aerodynamic shape and flight control: First, in aerodynamic design, the blended wing-body layout optimizes lift distribution and minimizes induced drag. Optimizing the airfoil of the fuselage and wings, as well as key geometric parameters such as the wing-body aspect ratio, increases lift and reduces pressure drag and surface friction drag, thus significantly improving the lift-to-drag ratio. Second, the use of anhedral design at the wingtips further reduces induced drag and improves aerodynamic efficiency. Finally, in flight control, the addition of a V-tail enhances the pitch and yaw stability of the UAV. Combined with the natural roll stability provided by the wide-body shape unique to the blended wing-body layout, it achieves attitude stability during cruise. Furthermore, the additional attitude balancing capability provided by the three sets of control surfaces further improves the stability of the UAV under different flight conditions.
[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0062] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. An aerodynamic shape for a blended wing-body unmanned aerial vehicle (UAV), comprising a wing-body portion, characterized in that: A V-tail is mounted on the rear end of the upper surface of the wing-body section, and an engine is mounted between the opposite surfaces of the V-tail. Both the wing-body section and the V-tail are equipped with control surfaces. A landing gear is mounted on the lower surface of the wing-body section. The wing body includes an inner wing and an outer wing, the inner wing and the outer wing are arranged symmetrically, and the edge of the outer wing is fitted with a wingtip; The leading edge sweep angle of the wing-body section is 20°, and the trailing edge sweep angle of the wing-body section is 17°; The wing body is generated using three cross sections and three guide lines, with the midpoint of the leading edge as the coordinate origin (0, 0, 0) mm. The wingtip is extended from the outer wing to the point (1520, 265, 2187.5) mm to form a closed structure. The three sections of the wing body are located at spanwise 0, 1250, and 2062.5 mm, respectively; The airfoil section located at 0mm span has an airfoil section of MH91, scaled proportionally to a chord length of 2000mm, with a blunt trailing edge of 10mm height. The leading edge point of the airfoil section is the origin (0, 0, 0)mm. The airfoil section located at 1250mm span is ONERAOA209, proportionally scaled down to a chord length of 450mm. The leading edge point of the airfoil is (950, 100, 1250)mm. The airfoil is twisted by -1° around the Z-axis at 1 / 4 chord length and by -4° around the X-axis. The airfoil section located at 2062.5 mm span is a self-designed airfoil, scaled proportionally to a chord length of 250 mm. The leading edge point of the airfoil is (1250, 190, 2062.5) mm. The airfoil is twisted 2° around the Z-axis at 1 / 4 chord length and -21° around the X-axis.
2. The aerodynamic shape of a blended wing-body UAV according to claim 1, characterized in that: The overall geometric parameters of the wing-body section include the wingspan. =4.375m; wing area =2.08m 2 Aspect Ratio =9.2; Flange root chord length =0.758m; mean aerodynamic chord length =0.546m; Root-to-shoot ratio =0.33; 1 / 4 chord sweep angle =17°.
3. The aerodynamic shape of a blended wing-body UAV according to claim 2, characterized in that: The V-shaped tail fin is formed by two cross sections, and the wingtip of the V-shaped tail fin is formed by extending 60mm from the main body of the V-shaped tail fin to form a closed shape. The V-tail has a vertical tail height of 700 mm, a root chord length of 492 mm, a leading edge sweep angle of 28°, and a root-to-tip ratio of 0.
3.
4. The aerodynamic shape of a blended wing-body UAV according to claim 3, characterized in that: The two sections of the V-shaped tail fin are located at 0 and 640 mm span, respectively. The cross-sectional airfoil of the V-tail located at 0mm span is NACA0008, scaled proportionally to a chord length of 492mm; The V-tail wing located at a span of 640 mm has a cross-sectional airfoil of NACA0008, scaled proportionally to a chord length of 147.6 mm, and the leading edge point of the V-tail wing is (300, 640, 0). The V-shaped tail fin was first rotated -2° around the Y-axis, then rotated 41.7° around the X-axis, and finally translated to the coordinates (1300, 0, 300) mm of the leading edge point of the wing root of the V-shaped tail fin.
5. The aerodynamic shape of a blended wing-body UAV according to claim 1, characterized in that: The V-tail geometry parameters include: horizontal projected tail volume of 0.7; vertical projected tail volume of 0.11; wingspan... =0.64m; wing area =0.2045; Flange root chord length =0.492m; root-to-shoot ratio =0.3; V-shaped tail fin leading edge sweep angle =28°; the angle between the V-tail fin surface and the V-tail fin symmetry plane =41.7°.
6. The aerodynamic shape of a blended wing-body UAV according to claim 1, characterized in that: The landing gear consists of a front wheel and two main wheels. The front wheel controls the direction of the plane when it is sliding on the ground, while the main wheels bear the main weight and control the brakes.
7. The aerodynamic shape of a blended wing-body UAV according to claim 1, characterized in that: The control surface includes an elevator, a rudder, and an aileron. The elevator is located in the middle of the trailing edge and is 300 mm wide. The elevator is located at the leading edge at X=1600 mm. The maximum upward deflection angle of the elevator is 30° and the maximum downward deflection angle of the elevator is 20°. The rudder is located on the V-shaped tail fin, between 192mm and 640mm in span of the V-shaped tail fin. The width of the rudder is 0.3 times the chord length of the corresponding section, and the maximum deflection angle of the rudder is ±20°. The aileron is located on the trailing edge of the outer wing, between 1100mm and 1800mm along the wing span of the wing body portion. The width of one end of the aileron is 0.2 times the chord length of the corresponding section, and the width of the other end of the aileron is 0.25 times the chord length of the corresponding section. The maximum upward deflection angle of the aileron is 25°, and the maximum downward deflection angle of the aileron is 20°.