Low subsonic to high supersonic speed wide speed regime morphing aerodynamic configuration for a cruise missile

Abstract

The application provides a low-subsonic to high-subsonic wide-speed-range deformable aerodynamic layout of a cruise missile, comprising double-axis variable sweep wing mechanisms arranged at the bottom of a fuselage, capable of arbitrarily changing and locking a sweep angle in a range of 0-90 degrees, each double-axis variable sweep wing mechanism comprising an inner wing segment and an outer wing segment, the inner wing segment being pivotally connected with the fuselage at a wing root, and the inner wing segment being adjusted at a front sweep angle in a range of 0-90 degrees; the outer wing segment being pivotally connected with the inner wing segment at a wing tip, and the outer wing segment being adjusted at a rear sweep angle in a range of 0-90 degrees; and the nose being blunt. In the embodiment, the double-axis variable sweep wing mechanism has opposite influence trends of the inner wing segment and the outer wing segment on the center of pressure of the cruise missile during stretching, folding and flying, so as to control the change range of the center of pressure of the cruise missile in a very small interval, and make the wing sweep process have good maneuvering and stability characteristics and flight stability. In addition, the double-axis variable sweep wing mechanism is parallel to the fuselage when being folded, so that the cruise missile is convenient to store and transport, and the storage and deployment capability is improved.

Description

Technical Field

[0001] This invention relates to the field of loitering munitions, and in particular to an aerodynamic configuration for a loitering munition with a high subsonic wide speed range. Background Technology

[0002] With the development of aviation technology, loitering munitions or drones are playing an increasingly prominent role in military reconnaissance, battlefield surveillance, precision strikes, and civilian logistics, remote sensing and mapping.

[0003] Modern mission scenarios place higher demands on the performance of loitering munitions or unmanned aerial vehicles (UAVs), requiring them to possess a wide speed range from low subsonic to high subsonic (Ma<0.8) and a broad airspace capability within a single mission. An ideal loitering munition or UAV should be able to cruise at low speeds, such as loitering and observing over a target area for extended periods, requiring an extremely high lift-to-drag ratio to improve flight time and range. An ideal loitering munition or UAV should also possess high-speed penetration / deployment capabilities, specifically the ability to quickly arrive at or leave the mission area, minimizing exposure to enemy fire. This requires overcoming transonic shock wave drag and maintaining a stable flight attitude.

[0004] Related loitering munitions or drones employ single-axis variable-sweep wings, tandem folding wings, or fixed-wing-body blended folding wings to achieve a wide speed range and high aspect ratio. Among these, the fixed-wing-body blended folding wing configuration is common in small loitering munitions or drones requiring tube-launch. It uses a fixed conventional or tandem wing layout, but to accommodate the size constraints of the launch tube, the wings are designed to fold backward as a single wing or with the fore wing swept backward and the rear wing swept forward. After launch, the wings unfold and lock into a fixed straight or swept-back wing configuration under the action of springs or actuators.

[0005] Even if the above scheme is adopted to achieve deformable flight with high lift-to-drag ratio at low and high subsonic speeds and a wide speed range at high subsonic speeds, the following problems still exist: 1. Employ a single-axis variable-sweep wing or a tandem folding wing: 1) Achieving high lift-to-drag ratio aerodynamic performance only at a single cruise speed: A single-axis variable-sweep wing, at a fixed speed (such as low subsonic or high subsonic), achieves high lift-to-drag ratio flight at that speed by matching a single sweep angle to that cruise speed. Tandem folding wings can only be used for low subsonic loitering and cannot be adapted for high subsonic cruise.

[0006] 2) Achieving high lift-to-drag ratio over a wide speed range through deformation, but also encountering problems such as large shifts in the center of pressure and structural flight control divergence: The overall rotation of a single-axis variable-sweep wing causes significant forward and backward shifts in the aerodynamic center (pressure point) as the speed range changes. To balance the resulting pitching moment, the horizontal stabilizer needs to provide a large trim force, which introduces additional trim drag. Sacrificing significant lift-to-drag ratio gains is unprofitable and may even prevent stable control. A tandem wing configuration with forward-swept deformation of the rear wing leads to static and dynamic aeroelastic divergence during high subsonic flight.

[0007] 2. Adopting a fixed wing-body blended folding wing: 1) Fixed aerodynamic layout: The wing's shape is fixed once deployed and cannot be optimized according to speed changes during flight. Its aerodynamic design can only be a compromise for a specific cruise speed, and it cannot achieve a high lift-to-drag ratio across the entire speed range.

[0008] 2) Poor speed range adaptability: If a straight wing is used to optimize low-speed performance, shock waves will appear too early during high subsonic flight, resulting in drag divergence; if a swept wing is used to optimize high-speed performance, the lift-drag characteristics during low-speed cruise will be reduced.

[0009] 3) Complex structure and large space occupation: The pivot mechanism needs to withstand huge concentrated loads, resulting in a large structural weight. When the wing rotates, a large wing box space is required to store the pivot and the wing root, which occupies valuable space inside the fuselage and is not conducive to the folding, storage, dense loading, transportation and launch of loitering munitions or UAVs. Summary of the Invention

[0010] The summary section of this invention provides a brief overview of the concepts, which will be described in detail in the detailed description section that follows. This summary section is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0011] Some embodiments of the present invention provide aerodynamic configurations for loitering munitions with a high subsonic wide speed range to address the technical problems mentioned in the background section above.

[0012] Some embodiments of the present invention provide a deformable aerodynamic configuration for a loitering munition with a wide speed range from low subsonic to high subsonic, including a dual-axis variable-sweep wing mechanism disposed at the bottom of the fuselage, forming a low-wing configuration, capable of arbitrarily changing and locking the sweep angle within the range of 0° to 90°, wherein... Each of the aforementioned dual-axis variable sweep wing mechanisms includes an inner wing section and an outer wing section. The wing root of the inner wing section is pivotally connected to the fuselage and can rotate relative to the fuselage, thereby adjusting the forward sweep angle of the inner wing section within any angle from 0° to 90°. The outer wing root is pivotally connected to the inner wing tip, allowing it to rotate relative to the inner wing section, thus adjusting the sweep angle of the outer wing section at any angle from 0° to 90°. The machine head has a blunt-tipped design.

[0013] The above embodiments of the present invention have the following beneficial effects: During the extension, folding, and sweeping processes, the inner and outer wing sections of the dual-axis variable-sweep wing mechanism have opposite effects on the pressure center of the loitering munition, thus compensating for each other. This keeps the pressure center variation range within a very small range, fundamentally improving the stability and maneuverability problems caused by the drastic pressure center changes of the variable-sweep wing. As a result, the wing has good handling and stability characteristics and flight stability during the sweeping process, and its aerodynamic stability is significantly improved.

[0014] In addition, the dual-section folding design allows the dual-axis variable sweep wing mechanism to be parallel to the fuselage after folding, making it easy to store in the weapon system's launch tubes, launch racks, and other devices. It also facilitates transportation, allowing the main support point or launch slider to be directly placed on the robust fuselage belly. The structure is simple and reliable, and it is easy to install into the launch tube, improving storage and deployment capabilities.

[0015] Finally, the nose cone has a blunt-nosed design, which provides a large and stable head space, making it easy to integrate payloads such as seekers and optoelectronic payloads through mechanical interfaces and mounting bases. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a top view of an embodiment of the deformable aerodynamic layout of the loitering munition of the present invention in a wide speed range from low subsonic to high subsonic. Figure 2 This is a front view of an embodiment of the deformable aerodynamic layout of the loitering munition of the present invention in a wide speed range from low subsonic to high subsonic. Figure 3 This is a swept-back top view of an embodiment of the deformable aerodynamic configuration of the loitering munition of the present invention in a wide speed range from low subsonic to high subsonic. Figure 4 This is a top view of the retracted state of an embodiment of the deformable aerodynamic layout of the loitering munition of the present invention, which has a wide speed range from low subsonic to high subsonic. Figure 5This is a front view of the retracted state of an embodiment of the deformable aerodynamic layout of the loitering munition of the present invention, which has a wide speed range from low subsonic to high subsonic. Figure 6 This is a schematic diagram showing the change in stability of the single-axis and dual-axis variable-sweep wing mechanisms of the loitering munition of the present invention with the deployment angle at low subsonic speeds (e.g., Ma=0.2). Figure 7 Schematic diagrams of high lift-drag subsonic airfoils, supercritical airfoils, and weighted optimized airfoils.

[0018] Explanation of reference numerals in the attached figures: 11. Nose; 12. Fuselage; 13. Tail; 131. Y-tail; 2. Dual-axis variable sweep wing mechanism; 21. Inner wing section; 211. Inner wing section root; 212. Inner wing section tip; 22. Outer wing section; 221. Outer wing section root; 222. Outer wing section tip. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] Please see Figures 1 to 6 The aerodynamic layout of the loitering munition of the present invention, which has a high subsonic speed range, includes a dual-axis variable sweep wing mechanism 2 disposed at the bottom of the fuselage 12. Each dual-axis variable sweep wing mechanism 2 includes an inner wing section 21, an inner wing pivot, an outer wing section 22, and an outer wing pivot.

[0024] The fixed end of the inner wing pivot is connected to the bottom of the fuselage 12, and the driving end of the inner wing pivot is connected to the wing root 211 of the inner wing section. The aforementioned inner wing pivot is used to adjust the forward sweep angle of the inner wing section 21, so that the inner wing section 21 is parallel or perpendicular to the longitudinal axis of the fuselage 12.

[0025] The fixed end of the outer wing pivot is connected to the wingtip 212 of the inner wing section, and the driving end of the outer wing pivot is connected to the wing root 221 of the outer wing section. The aforementioned outer wing pivot is used to adjust the sweep angle of the outer wing section 22, so that the outer wing section 22 is parallel or perpendicular to the longitudinal axis of the fuselage 12.

[0026] By driving the inner wing pivot and the outer wing pivot to rotate respectively, the extension and folding of the dual-axis variable sweep wing mechanism 2 can be realized.

[0027] Specifically, during extension, the inner wing pivot drives the inner wing section tip 212 to rotate around the inner wing section root 211. The inner wing section 21 can rotate from being parallel to the longitudinal axis of the fuselage 12 to being perpendicular to the longitudinal axis of the fuselage 12, and the forward sweep angle can be adjusted from 90° to 0°. Simultaneously, the outer wing pivot drives the outer wing section tip 222 to rotate around the outer wing section root 221. The outer wing section 22 can rotate from being parallel to the longitudinal axis of the fuselage 12 to being perpendicular to the longitudinal axis of the fuselage 12, and the backward sweep angle can be adjusted from 90° to 0°. The inner wing section 21 and the outer wing section 22 transform from a folded state to an inverted V-shaped state to an extended state. The dual-axis variable sweep wing mechanism 2 forms an M-shaped overall configuration and finally transforms back to a folded state. In this way, the relative deployment angle between the inner wing section 21 and the outer wing section 22 increases from 0° to 180°.

[0028] It should be noted that the inner wing section 21 and the outer wing section 22 mentioned above can independently change their angles and have asymmetrical deformation capabilities on both sides, so as to realize the change of the overall aerodynamic configuration to adapt to different flight speeds from low subsonic to high subsonic.

[0029] The inner wing pivot and the outer wing pivot can be a servo motor with a self-locking function, thereby locking the inner wing section 21 and the outer wing section 22 after adjusting the forward and backward sweep angles.

[0030] After the dual-axis variable-sweep wing mechanism 2 is fully extended, it significantly increases the wing's aspect ratio, thereby improving the aircraft's lift and drag performance. During the extension process, the centroid of the inner wing section 21 shifts rearward, while the centroid of the outer wing section 22 shifts forward. The changes in the wing's center of pressure and focal point are relatively small, resulting in good handling and stability characteristics during the wing's extension process.

[0031] During folding, the inner wing pivot drives the inner wing tip 212 to rotate around the inner wing root 211, causing the inner wing section 21 to rotate from perpendicular to the longitudinal axis of the fuselage 12 to parallel to the longitudinal axis of the fuselage 12, and completely retract to the bottom of the fuselage, with the forward sweep angle varying from 0° to 90°. Simultaneously, the outer wing pivot drives the outer wing tip 222 to rotate around the outer wing root 221, causing the outer wing section 22 to rotate from perpendicular to the longitudinal axis of the fuselage 12 to parallel to the longitudinal axis of the fuselage 12, with the backward sweep angle varying from 0° to 90°. The inner wing section 21 and the outer wing section 22 transition from an extended state to an inverted V-shaped state, forming an M-shaped overall configuration through the dual-axis variable sweep wing mechanism 2, and finally deforming into a folded state. In this way, the inner wing section 21 and the outer wing section 22 can achieve any relative deployment angle from 180° to 0°.

[0032] The outer wing section 22 is longer than the inner wing section 21, which reduces the change in the center of gravity of the entire missile during the folding and unfolding process, helps to reduce aerodynamic disturbances and improve the stability of the entire missile during unfolding.

[0033] After folding, the dual-axis variable-sweep wing mechanism 2 is parallel to the fuselage, facilitating its storage in weapon system launch tubes, launch racks, and other devices. It also facilitates transportation, allowing the main support point or launch slider to be directly positioned on the robust underside of the fuselage 12. The structure is simple, reliable, and easy to install into the launch tube. During folding, the centroid of the inner wing section 21 moves forward, while the centroid of the outer wing section 22 moves backward, resulting in minimal changes to the wing's center of pressure and focal point. This gives the wing excellent handling characteristics and flight stability during the variable-sweep process.

[0034] During flight, in low-speed, high-efficiency modes such as takeoff and cruise, both the inner wing section 21 and the outer wing section 22 are controlled to have small or 0-degree sweep angles. At this time, the entire wing approximates a high-aspect-ratio straight wing in the top-view plane. This maximizes the effective wingspan and lift line slope, achieving an extremely high lift-to-drag ratio at low speeds. In high-speed, high-efficiency modes such as penetration and sprint, the inner wing pivot drives the inner wingtip 212 to sweep forward around the inner wing root 211, while the outer wing pivot drives the outer wingtip 222 to sweep backward around the outer wing root 221, forming a symmetrical M-shaped configuration. The sweepback of the outer wing section 22 increases its effective sweep angle, effectively increasing the wing's critical Mach number, delaying and weakening the shock wave intensity in the outer wingtip 222 region at high subsonic speeds, and significantly reducing wave drag. Through the coordinated and symmetrical deflection of the inner wing section 21 and the outer wing section 22, the wing actively adapts to the flow field by changing its planar shape at different speeds, thereby maintaining a high lift-to-drag ratio across a wide speed range from low subsonic speeds to high subsonic speeds (Ma<0.8). At low subsonic speeds (e.g., Ma=0.2), the maximum lift-to-drag ratio is >16.0, and at Ma=0.8, the maximum lift-to-drag ratio is >12.0.

[0035] Furthermore, an aerodynamic self-compensation mechanism is constructed by designing the chord length ratio of the inner wing section 21 and the relative position of the rotation axis of the outer wing section 22. During the structural design phase, aerodynamic calculations and optimizations determine the mounting points of the inner and outer wing rotation axes on the fuselage and the inner wing section. When the dual-axis variable-sweep wing mechanism 2 transforms from a straight configuration to an M-shaped configuration, the swept outer wing section, due to its aerodynamic center shifting rearward, tends to shift the focal point of the entire aircraft rearward; while the swept inner wing section 21, due to its aerodynamic center shifting forward, tends to shift the focal point of the entire aircraft forward. Through parameter matching, the forward shift effect of the inner wing section 21 and the backward shift effect of the outer wing section 22 are made approximately equal and opposite in aerodynamic calculations, thus technically ensuring that the forward and backward movement of the aerodynamic focal point of the entire aircraft is limited to a small range throughout the variable-sweep process. This allows the aircraft to achieve efficient flight across a wide speed range without incurring significant trim drag, fundamentally improving the stability and controllability challenges caused by abrupt changes in the pressure center of traditional single-axis variable-sweep wings, resulting in a significant improvement in aerodynamic stability. Please refer to [link / reference]. Figure 6 , Figure 6 This is a schematic diagram showing how the stability of a single-axis variable-sweep wing and a dual-axis variable-sweep wing mechanism changes with the deployment angle at low subsonic speeds (such as Ma=0.2).

[0036] Furthermore, the unique dual-section folding design enables the dual-axis variable-sweep wing mechanism 2 to transform from its operational state to its stowed state. In the non-operational state (such as during ground transport or placement inside the launch tube), the inner wing section 21 and the outer wing section 22 are controlled to rotate around their respective axes until the leading or trailing edges of the inner wing section 21 and the outer wing section 22 are both close to and parallel to the longitudinal axis of the fuselage, forming a bundled state with minimized lateral dimensions. This allows the variable-sweep capability of the loitering munition during flight to be reused for ground storage, greatly improving the platform's portability and deployment flexibility.

[0037] like Figure 7 As shown, the target airfoils for the inner wing section 21 and the outer wing section 22 can be high lift-drag subsonic airfoils or supercritical airfoils, such as the NACA4412 subsonic airfoil and the NACA SC(2)-0710 supercritical airfoil.

[0038] In order to take into account both subsonic, transonic and supersonic flight states, the target airfoils of the inner wing section 21 and the outer wing section 22 can also be obtained by optimizing the high lift and drag subsonic airfoils and supercritical airfoils, such as the weighted average of the NACA4412 subsonic airfoil and the NACA SC(2)-0710 supercritical airfoil.

[0039] Specifically, the NACA 4412 airfoil is a typical subsonic airfoil, characterized by a high lift-to-drag ratio, high maximum lift coefficient, low minimum drag coefficient, wide low-drag range, and high critical Mach number. Its shape is characterized by a full nose and forward-prominent maximum thickness. However, a prominent issue encountered during high subsonic flight is the critical Mach number (MCR). When the incoming flow Mach number is less than the MCR, the flow around the airfoil is entirely subsonic. When the incoming flow Mach number exceeds the critical Mach number, a local supersonic region forms on the airfoil surface. This region ends with a shock wave and transitions to subsonic flow. Thus, the supersonic region surrounded by sound lines and shock waves, and the external subsonic flow, form two distinct flow regions.

[0040] NASA SC(2)-0710 airfoil is a typical supercritical airfoil. The upper surface is relatively flat in the middle, resulting in a relatively flat pressure distribution. The rear surface curves downwards. To compensate for the insufficient lift caused by the flat upper surface, there is an inwardly recessed rear loading on the lower surface, which increases the lift at the rear. This airfoil effectively delays the location of the shock wave and significantly reduces its intensity by forming a relatively gentle and extended pressure plateau on the upper surface, allowing the local flow to maintain a mild pressure gradient distribution over a wide range of angles of attack and Mach numbers.

[0041] To accommodate both cruise conditions of Ma=0.6 and Ma=0.8, a weighted average of the NACA4412 subsonic airfoil and the NACA SC(2)-0710 supercritical airfoil was obtained, as shown below. Figure 7 The target airfoil shown has the ability to balance lift, drag divergence, and stall characteristics when combined with a small camber and post-load.

[0042] Compared to traditional supercritical airfoils optimized for Mach 0.78–0.82, the target airfoil in the above-mentioned technical solution exhibits a more restrained geometric curvature distribution, avoiding the increased friction and decreased lift efficiency caused by excessive flat-top pressure distribution at low Mach numbers. Its approximately 9.5% relative thickness not only meets the structural strength and internal layout requirements of the UAV, but also, when combined with a swept-back configuration, effectively reduces the normal Mach number, ensuring the airfoil operates within a controllable, low-transonic range.

[0043] From an aerodynamic perspective, under swept conditions, the incoming flow normal Mach number is significantly lower than the free flow Mach number, and the design Mach number range of the target airfoil is highly compatible with this normal flow state. This results in a limited range of ultrasonic region on the upper surface of the target airfoil within the 0.6–0.8 Ma range, stable shock wave position, and low likelihood of inducing strong shock wave boundary layer coupling, thereby avoiding drag divergence and lift attenuation.

[0044] In the overall layout of a variable-sweep wing loitering munition, the target airfoil can achieve a good balance of aerodynamic performance without the need for complex leading or trailing edge modifications. Its insensitivity to changes in angle of attack allows the UAV to maintain stable aerodynamic characteristics during cruise, acceleration, and maneuvering, which is beneficial for flight control system design and envelope expansion.

[0045] In summary, the airfoil adopted in this aerodynamic layout can effectively control the increase of transonic drag without significantly sacrificing low-speed cruise efficiency. It reflects the engineering development trend of "wide design point and strong robustness" in the aerodynamic design of modern loitering munitions and has clear technical rationality and engineering advancement.

[0046] In this embodiment, the aircraft adopts a variable-sweep wing aerodynamic layout suitable for low-to-high subsonic flight envelopes of 0.2–0.8 Ma. After comprehensive consideration of overall layout and aerodynamic design, the outer wing section 22 is longer than the inner wing section 21 and folds using the length of the fuselage 12. The dual-axis variable-sweep wing mechanism 2, when deployed, is longer than the fuselage 1. As an example, the length of the inner wing section 21 is approximately 21% of the total aircraft length, and the length of the outer wing section 22 is approximately 40% of the total aircraft length. This ratio of inner wing section 21 to outer wing section 22 lengths is jointly determined by the lift-to-drag ratio formation mechanism under subsonic-transonic conditions and the transonic wave drag control requirements.

[0047] In the low-subsonic and high-subsonic speed range of 0.2–0.6 Ma, induced drag dominates the overall drag of the aircraft, and induced drag is significantly inversely proportional to the effective aspect ratio. The relatively large length of the outer wing section 22 allows the dual-axis variable-sweep wing mechanism 2 to achieve a large effective spanwise dimension in the deployed state, which is beneficial for forming a near-elliptical distribution of lift spanwise loads, thereby significantly reducing induced drag and improving the lift-to-drag ratio performance during subsonic cruise. The length of the outer wing section 22 reaches approximately 40% of the total aircraft length, enabling the dual-axis variable-sweep wing mechanism 2 to maintain a high level of lift efficiency without significantly increasing structural complexity, thus meeting the design goals of long endurance and high-efficiency cruise.

[0048] In high subsonic flight at speeds of 0.7–0.8 Ma, the appearance of shock waves becomes the primary factor contributing to the decrease in lift-to-drag ratio. The target airfoil, by creating a relatively gentle pressure plateau on its upper surface, effectively delays the location of shock wave appearance and reduces its intensity. However, the transonic advantage of this target airfoil can only be fully realized with a combination of appropriate sweep and reasonable spanwise dimensions. The length of the inner wing section 21 is controlled to approximately 21% of the total aircraft length, allowing it to undertake the main aerodynamic center adjustment and lift distribution functions during sweep variations, without excessively lengthening its spanwise dimension. This avoids the possibility of excessive spanwise lift from the inner wing section 21 under transonic conditions, which could induce an earlier shock wave or an increase in shock wave intensity.

[0049] Furthermore, the ratio of the inner wing section 21 to the outer wing section 22 is beneficial for maintaining stable changes in the aerodynamic focus position within the low-to-high subsonic envelope. The shorter inner wing section 21 and the longer outer wing section 22 mutually compensate for each other in their pitch moment contributions, limiting the aerodynamic center of gravity shift during Mach number changes, thereby reducing trim drag and the burden on the control system. Overall, the design of the inner wing section 21 accounting for 21% of the loitering munition's length and the outer wing section 22 accounting for 40% of the loitering munition's length achieves optimal lift-to-drag ratio across the subsonic to transonic range while ensuring controlled transonic wave drag, making it a reasonable aerodynamic layout suitable for subsonic to transonic UAVs.

[0050] Revisit Figure 1 and Figure 2 The fuselage 12 is equipped with a foldable Y-shaped tail 131 at its end. This invention adopts a low-wing aerodynamic configuration, which is beneficial to improving the roll stability and ground effect of the aircraft. The Y-shaped tail 131 layout is a highly efficient aerodynamic shape with low drag and low radar cross-section.

[0051] The nose section 11 adopts a blunt-nosed shape to provide a sufficiently large and structurally stable head space, facilitating the integration of payloads such as the seeker head and electro-optical payloads via mechanical interfaces and mounting bases. The tail section 13 and the engine exhaust nozzle adopt an integrated tapering design, blending the rear section of the engine mounting compartment with the curved surface of the tail section 13, allowing the fuselage tail cowl to smoothly transition to the engine exhaust nozzle, forming a streamlined, tapering shape that effectively reduces bottom drag.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deformable aerodynamic configuration for a loitering munition with a wide speed range from low subsonic to high subsonic, characterized in that, This includes a dual-axis variable-sweep wing mechanism located at the bottom of the fuselage, forming a low-wing configuration that can arbitrarily change and lock the sweep angle within a range of 0° to 90°. Each of the aforementioned dual-axis variable sweep wing mechanisms includes an inner wing section and an outer wing section. The wing root of the inner wing section is pivotally connected to the fuselage and can rotate relative to the fuselage, thereby adjusting the forward sweep angle of the inner wing section within any angle from 0° to 90°. The outer wing root is pivotally connected to the inner wing tip, allowing it to rotate relative to the inner wing section, thus adjusting the sweep angle of the outer wing section at any angle from 0° to 90°. The nose of the machine is blunt-nosed.

2. The deformable aerodynamic configuration of the loitering munition according to claim 1, spanning a wide speed range from low subsonic to high subsonic, is characterized in that... The dual-axis variable sweep wing mechanism also includes an inner wing pivot and an outer wing pivot. The fixed end of the inner wing pivot is connected to the bottom of the fuselage, and the driving end of the inner wing pivot is connected to the wing root of the inner wing section. The fixed end of the outer wing pivot is connected to the wingtip of the inner wing section, and the driving end of the outer wing pivot is connected to the wing root of the outer wing section; the inner and outer wing sections can independently change their sweep angle.

3. The deformable aerodynamic configuration of the loitering munition according to claim 2, spanning a wide speed range from low subsonic to high subsonic, is characterized in that... The inner wing pivot drives the inner wing section to rotate, and the forward sweep angle of the inner wing section can be adjusted from 90° to 0°. The outer wing pivot drives the outer wing section to rotate, and the sweep angle of the outer wing section can be adjusted from 90° to 0°. The relative deployment angle between the inner wing section and the outer wing section can be 0° to 180°.

4. The deformable aerodynamic configuration of the loitering munition according to claim 1, spanning a wide speed range from low subsonic to high subsonic, is characterized in that... After the dual-axis variable-sweep wing mechanism is folded, it is completely retracted to the bottom of the fuselage and parallel to the fuselage.

5. The deformable aerodynamic configuration of the loitering munition according to claim 1, spanning a wide speed range from low subsonic to high subsonic, is characterized in that... The target airfoils for the inner and outer wing sections are high lift-drag subsonic airfoils or supercritical airfoils, or airfoils obtained through weighted optimization.

6. The deformable aerodynamic configuration of the loitering munition according to claim 5, spanning a wide speed range from low subsonic to high subsonic, is characterized in that... The outer wing section is longer than the inner wing section; the inner wing section accounts for 21% of the total length of the loitering munition; the outer wing section accounts for 40% of the total length of the loitering munition.

7. The deformable aerodynamic configuration of the loitering munition according to claim 1, spanning a wide speed range from low subsonic to high subsonic, is characterized in that... The tail section and the engine exhaust nozzle adopt an integrated shrinking design.

8. The deformable aerodynamic configuration of the loitering munition according to claim 1, spanning a wide speed range from low subsonic to high subsonic, is characterized in that... The tail section is equipped with a foldable Y-shaped tail fin.

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