A dual row ducted fan augmented power system

Abstract

The application relates to the technical field of aircrafts, and particularly discloses a double-row duct fan synergistic power system, which comprises an aircraft lift component, a plurality of front duct fans and a plurality of rear duct fans; the plurality of front duct fans and the plurality of rear duct fans are used for providing thrust for the aircraft lift component; the plurality of front duct fans and the plurality of rear duct fans are arranged on the aircraft lift component; the plurality of front duct fans are used for cooperating with the plurality of rear duct fans to generate a lift-increasing effect by utilizing jet flow effect and suction effect; the double-row duct fan synergistic power system realizes deep integration of wing aerodynamic performance and duct propulsion performance; the double-row duct fan synergistic power system can improve lift and suppress flow separation in a low-speed and large-attack-angle state, improve propulsion efficiency and reduce energy loss in a cruising state, and thus significantly improves take-off and landing performance, cruising efficiency, endurance capability, effective load capacity and multi-working-condition adaptability of the aircraft.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and more specifically to a dual-row ducted fan enhanced propulsion system. Background Technology

[0002] Despite rapid technological advancements, existing eVTOL systems still face significant bottlenecks in practical applications, limiting their performance improvement and commercialization.

[0003] First, insufficient range remains a core technological challenge for eVTOLs. Limited by the energy density of existing batteries and the efficiency of traditional electric propulsion systems, the effective range and cruise time of most eVTOLs are still insufficient to meet the needs of long-distance travel and continuous multi-mission flight. For example, in regional transportation or emergency missions beyond short-distance urban commuting, existing aircraft struggle to balance takeoff and landing efficiency with range performance, limiting the expansion of their application scenarios.

[0004] Furthermore, low energy efficiency is a significant factor limiting the performance of eVTOLs. Existing electric propulsion system designs often employ single-row fans or simple multi-rotor layouts, frequently failing to adequately consider the coupling effect between aerodynamics and the propulsion system. At low speeds, during takeoff and landing, and at high angles of attack, wing lift and propulsive airflow cannot effectively coordinate, resulting in low energy conversion efficiency and uneven propulsion performance, further impacting endurance and power response speed. In addition, existing designs lack holistic consideration of wing aerodynamic optimization and system drag reduction, resulting in still relatively high energy losses and air resistance, hindering eVTOLs from achieving efficient, long-endurance flight.

[0005] In summary, the shortcomings of existing eVTOLs in terms of endurance and propulsion efficiency severely restrict their performance in urban air traffic, multi-mission cruise, and long-range applications, and also limit their commercialization and large-scale application. Summary of the Invention

[0006] The purpose of this invention is to provide a dual-row ducted fan enhanced propulsion system that achieves a deep integration of wing aerodynamic performance and ducted propulsion performance; it can improve lift and suppress flow separation at low speeds and high angles of attack, and improve propulsion efficiency and reduce energy loss during cruise, thereby significantly improving the aircraft's takeoff and landing performance, cruise efficiency, endurance, payload capacity and multi-condition adaptability.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A dual-row ducted fan enhanced propulsion system includes an aircraft lift component, multiple front ducted fans, and multiple rear ducted fans.

[0008] The aircraft's lift components are used to generate upward lift when moving forward.

[0009] Multiple of the aforementioned front ducted fans are used to provide thrust for the aircraft's lift components.

[0010] Multiple of the aforementioned ducted fans are used to provide thrust for the aircraft's lift components.

[0011] Multiple front ducted fans and multiple rear ducted fans are mounted on the aircraft's lift components.

[0012] The plurality of said front duct fans are also used in conjunction with the plurality of said rear duct fans to generate lift by utilizing jet and suction effects.

[0013] In the dual-row ducted fan enhanced propulsion system provided in at least one embodiment of this disclosure, the front ducted fan and the rear ducted fan are arranged forward and backward along the chord of the aircraft's lift component, and there is a chordal distance segment between the front ducted fan and the rear ducted fan, which serves as an airflow guiding surface.

[0014] The airflow guiding surface is used to ensure that the high-speed jet generated by the front ducted fan can fully couple with the upper surface of the aircraft's lifting component before reaching the air intake area of ​​the rear ducted fan, thereby injecting momentum into the upper surface of the aircraft's lifting component to increase airflow speed and improve the air intake conditions of the rear ducted fan.

[0015] The dual-row ducted fan efficiency enhancement system provided in at least one embodiment of this disclosure further includes: a first adjustment mechanism.

[0016] The first adjustment mechanism is used to control the jet direction of the front duct fan.

[0017] The first adjustment mechanism is mounted on the aircraft's lift component.

[0018] The dual-row ducted fan efficiency enhancement system provided in at least one embodiment of this disclosure further includes: a second adjustment mechanism.

[0019] The second adjustment mechanism is used to control the jet direction of the rear duct fan.

[0020] The second adjustment mechanism is disposed on the lift component of the aircraft.

[0021] In the dual-row ducted fan enhanced propulsion system provided in at least one embodiment of this disclosure, the front ducted fan and the rear ducted fan are arranged in one of the following ways in the spanwise direction of the aircraft's lift components: array arrangement, one-to-one correspondence arrangement, staggered arrangement, interleaved arrangement, equidistant arrangement, or non-equidistant arrangement.

[0022] In at least one embodiment of the dual-drain fan enhanced propulsion system provided by this disclosure, the jet direction of the front duct fan is directed toward the rear region of the upper surface of the aircraft's lift component.

[0023] The air intake direction of the rear ducted fan is toward the jet development area of ​​the front ducted fan or the airflow guide surface.

[0024] In at least one embodiment of the dual-row ducted fan enhanced propulsion system provided in this disclosure, the aircraft lift component is provided with flaps.

[0025] The second adjustment mechanism is also used to adjust the angle of the flap.

[0026] In a dual-row ducted fan enhanced power system provided by at least one embodiment of this disclosure, the flaps are configured to be linked to the rear ducted fan.

[0027] In the dual-row ducted fan enhanced propulsion system provided in at least one embodiment of this disclosure, the aircraft lifting component is one of the following: fuselage, straight wing, swept wing, forward-swept wing, folding wing, variable chord length wing, blended wing-body structure, canard, annular wing, compound wing, or distributed lifting body structure.

[0028] The beneficial effects of this invention are as follows: By arranging a front ducted fan and a rear ducted fan along the chord direction on the upper surface of the aircraft's lifting components, a dual-row ducted fan power layout is formed, integrating the ducted fans with the wing's aerodynamic shape. Compared to traditional single-row ducted fan layouts or arrangements where the ducted fans and wings are independently arranged, this invention can fully utilize the flow field on the upper surface of the aircraft's lifting components. The ducted fans are no longer merely propulsion components generating thrust independently, but simultaneously participate in surface flow regulation, boundary layer energy replenishment, trailing edge flow control, and overall propulsion efficiency optimization, thereby improving the comprehensive performance of the aircraft's aerodynamic and propulsion systems.

[0029] Active momentum injection is achieved into the boundary layer on the upper surface of the aircraft's lifting components by utilizing the jet effect of a front-ducted fan. The front-ducted fan is positioned at or near the leading edge of the wing, and its high-speed jet propagates rearward along the upper surface of the wing, coupling with the boundary layer on the upper surface of the lifting components. This jet effect increases the airflow velocity on the upper surface of the lifting components, enhances the boundary layer's resistance to adverse pressure gradients, and increases the circulation of the lifting components, thereby effectively increasing lift. Especially during takeoff, landing, low-speed flight, and high angle-of-attack flight, this jet lift enhancement significantly improves the lift deficiency caused by insufficient incoming flow velocity. It increases lift and suppresses flow separation at low speeds and high angles of attack, and improves propulsion efficiency and reduces energy loss during cruise. This significantly improves the aircraft's takeoff and landing performance, cruise efficiency, range, payload capacity, and multi-condition adaptability. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a side view of the dual-row ducted fan enhanced power system in Example 1.

[0032] Figure 2 This is a perspective view of the dual-row ducted fan enhanced power system in Example 2.

[0033] Figure 3 This is a schematic diagram showing the distribution of the first and second adjustment mechanisms in Example 2.

[0034] Figure 4 This is a schematic diagram showing the connection between the first and second adjustment mechanisms and the aircraft's lift components.

[0035] In the picture: 10. Aircraft lifting components; 11. External wing spars; 12. Flaps; 13. Wing ribs; 14. Lateral wing spars; 20. Front ducted fan; 24. Mounting bracket; 30. Rear duct fan; 40. First adjusting mechanism; 41. Drive motor; 42. Rotating shaft; 43. Driven gear; 44. Driving gear; 50. Second regulating mechanism. Detailed Implementation

[0036] The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments, not all embodiments.

[0037] This invention provides a dual-row ducted fan enhanced propulsion system that utilizes the range-extending characteristics of aerodynamic-propulsion coupling to improve the system's propulsion performance. By rationally designing the distribution position, spacing, installation angle, and jet deflection angle of the front and rear ducted fans on the aircraft's lift components, the uniformity of the intake airflow field in the rear duct can be effectively improved, reducing intake distortion. Simultaneously, the intake saturation threshold of the rear duct can be increased, thus improving the system's propulsion performance. This aerodynamic coupling layout design enhances the propulsion performance of the novel propulsion system, reduces energy loss, and thereby helps eVTOL aircraft achieve efficient, long-endurance flight, meeting the needs of multiple mission scenarios such as cruise flight.

[0038] Example 1 like Figure 1As shown, this embodiment provides a dual-row ducted fan enhanced propulsion system, including an aircraft lift component 10, multiple front ducted fans 20 and multiple rear ducted fans 30.

[0039] Multiple front ducted fans 20 and multiple rear ducted fans 30 are all mounted on the upper surface of the aircraft's lift component 10. The multiple front ducted fans 20 and multiple rear ducted fans 30 work together to generate lift by utilizing jet flow and suction effects.

[0040] The front ducted fan 20 is located on the upper surface of the aircraft lifting component 10 near the leading edge, and the rear ducted fan 30 is located on the upper surface of the aircraft lifting component 10 near the trailing edge, thereby forming a front and rear dual-row power layout on the upper surface of the aircraft lifting component 10.

[0041] For example, along the spanwise direction of the aircraft lift component 10, the front ducted fan 20 and the rear ducted fan 30 can be arranged in an array, and the front ducted fan 20 and the rear ducted fan 30 can be arranged in a corresponding, staggered or interleaved manner to adapt to different aircraft configurations and aerodynamic design requirements.

[0042] The one-to-one correspondence arrangement means that the front ducted fan 20 and the rear ducted fan 30 are basically corresponding in spanwise position.

[0043] The staggered or interleaved arrangement refers to the rear ducted fan 30 having a certain offset relative to the front ducted fan 20 in the spanwise direction. By using different spanwise arrangement methods, the effective range between the front exhaust jet and the rear air intake can be adjusted, local flow field interference can be reduced, and the intake uniformity at the inlet of the rear ducted fan can be improved.

[0044] A directional aerodynamic coupling relationship is formed between the front ducted fan 20 and the rear ducted fan unit. The exhaust outlet direction of the front ducted fan 20 and the air inlet direction of the rear ducted fan unit maintain a preset relative orientation in space, and there is a preset chordal distance between them. The local upper surface of the aircraft lift component 10 located at this distance serves as an airflow guiding surface. By rationally designing the distribution position, distribution spacing, installation angle, and exhaust deflection angle of the front and rear ducted fan units on the wing, the high-speed airflow discharged by the front ducted fan 20 can be guided along the upper surface of the wing to the air intake area of ​​the rear ducted fan unit, thereby improving the air intake quality of the rear ducted fan unit and realizing the synergistic utilization of the front exhaust energy and the rear suction effect.

[0045] The structure of the front ducted fan 20 and the rear ducted fan 30 will be disclosed below.

[0046] The front ducted fan 20 and the rear ducted fan 30 form a double row. In this embodiment, the specific number of ducted fans in each row is not limited. There can be one, two, or more front ducted fans 20, and there can also be one, two, or more rear ducted fans 30.

[0047] Furthermore, the term "double row" should not be narrowly interpreted as two strictly parallel straight lines. In actual aircraft layouts, the front and rear rows can be distributed along the chord direction, oblique chord direction, curved chord direction, or local streamline direction of the wing. The front ducted fan 20 and the rear ducted fan 30 can be arranged in an arc shape along the wing surface curvature, or they can be arranged in a broken line shape, arc shape, or segmented arrangement according to the wing shape. As long as the ducted fan unit is relatively forward and the ducted fan unit is relatively backward in the direction of airflow development, it can be regarded as the front and rear rows in the sense of this embodiment.

[0048] Specifically, both the front ducted fan 20 and the rear ducted fan 30 include a duct housing (not shown), a fan blade assembly (not shown) disposed inside the duct housing, and a motor drive device (not shown) for driving the fan blade assembly to rotate. The front ducted fan 20 and the rear ducted fan 30 are installed at a preset angle.

[0049] In this embodiment, a mounting base 24 is fixedly disposed on the duct shell. The mounting base 24 can be disposed on the upper surface of the aircraft lifting component 10 and connected to the internal load-bearing structure of the aircraft lifting component 10 to transfer the thrust load, vibration load and aerodynamic load generated during the operation of the ducted fan to the main body of the aircraft lifting component 10. The mounting base 24 adopts a low-drag shape design to reduce its disturbance to the airflow on the upper surface of the aircraft lifting component 10.

[0050] Specifically, the fan blade assembly rotates under the action of a motor drive to generate suction airflow. The motor drive is located in the central area of ​​the duct to reduce the interference of exposed structures on the flow field.

[0051] For example, the duct shell can be circular, elliptical, rectangular with rounded corners, flat annular, polygonal, airfoil-section annular, or an irregularly shaped duct structure integrated with the wing shape. The duct shell can be a completely closed duct, or it can be a semi-duct, a partially covered duct, an embedded duct, or a duct structure integrally formed on the surface of the aircraft lift component 10.

[0052] For example, the fan blade assembly may be a single-stage fan, a multi-stage fan, a fixed-pitch fan, a variable-pitch fan, a coaxial counter-rotating fan, a fan with guide vanes, a fan without guide vanes, or a fan structure with a rectifier grid.

[0053] For example, the front ducted fan 20 and the rear ducted fan 30 may also be configured with an intake rectifier, an outlet guide vane, a nozzle contraction section, a diffuser section, a silencing structure, a variable area nozzle, variable guide vanes, or a tail nozzle deflection mechanism. These additional structures can further alter the jet velocity, jet direction, intake uniformity, or noise characteristics. These additional structures do not change the core technical concept of the invention and remain optional embodiments of the dual-row ducted power enhancement system of the present invention.

[0054] Specifically, the central axis of the front ducted fan 20 and / or the rear ducted fan 30 can form a preset installation tilt angle relative to the chord direction of the aircraft lift component 10, the local tangential direction of the upper surface of the aircraft lift component 10, or the reference plane of the aircraft lift component 10. The preset installation tilt angle can be determined based on the local curvature of the upper surface of the aircraft lift component 10, the jet direction of the ducted fan, the air intake direction of the rear duct, and the lift and propulsion requirements of the aircraft under different operating conditions.

[0055] The structure of the aircraft's lift component 10 will be disclosed below.

[0056] The aircraft's lifting component 10 can adopt a conventional fixed-wing form with a predetermined curvature distribution. However, this embodiment is not limited to this specific wing form. The wing can also be a fuselage, a straight wing, a swept wing, a forward-swept wing, a folding wing, a variable chord length wing, a blended wing-body structure, a canard, a ring wing, a compound wing, or a distributed lifting body structure. As long as the wing surface / fuselage surface can support the front ducted fan 20 and the rear ducted fan 30, and can allow the exhaust flow of the front ducted fan to flow along the wing surface to the air intake area of ​​the rear ducted fan, it is considered an equivalent form of the wing in this embodiment.

[0057] The aerodynamic shape of the wing's upper surface is not limited to a single continuous curved surface. It can be a continuous smooth curved surface or a composite curved surface formed by combining multiple curvature segments; it can be a convex surface, a partially concave surface, an S-shaped surface, or a surface with locally guiding ramps. The wing's upper surface can also be provided with guide slots, fairings, strakes, deflectors, vortex generators, boundary layer control slots, locally recessed channels, or raised guiding surfaces to assist the front jet flow in moving towards the rear ducted fan inlet. Any of the above-mentioned wing shapes that can achieve front jet guidance, boundary layer momentum replenishment, or rear suction flow field management can be used as alternative implementations of this embodiment.

[0058] Example 2 like Figure 2-4 As shown, this embodiment provides a dual-row ducted fan efficiency enhancement power system, which differs from Embodiment 1 in that it further includes a first adjustment mechanism 40 and a second adjustment mechanism 50.

[0059] The first adjustment mechanism 40 and the second adjustment mechanism 50 can adjust the installation angle or jet direction of the front ducted fan 20 and the rear ducted fan 30 according to flight conditions, aerodynamic requirements, and propulsion requirements, thereby changing the coupling relationship between the jet of the front ducted fan and the flow field on the upper surface of the wing. The angle adjustment of the front ducted fan 20 and the rear ducted fan 30 can be controlled independently or in concert. Therefore, this embodiment can not only improve lift enhancement during takeoff and landing and low-speed phases, but also reduce drag and improve propulsion efficiency during cruise phases, and enhance the overall aerodynamic propulsion performance of the aircraft under multiple operating conditions.

[0060] This embodiment's dual-row ducted fan enhancement design is based on active flow control theory, utilizing the jet and suction effects of the ducted fans to generate system lift. This coupling characteristic, leveraging the ducted propulsion characteristics and wing aerodynamics, optimizes the aircraft's aerodynamic performance, ensuring excellent aerodynamic characteristics even at low speeds and high angles of attack. This embodiment further utilizes the range-extending characteristics of aerodynamic-propulsion coupling to improve the system's propulsion characteristics. By rationally designing the distribution position, spacing, installation angle, and jet deflection angle of the front and rear ducted fans on the wing, the uniformity of the intake airflow field in the rear duct can be effectively improved, reducing intake distortion. Simultaneously, the intake saturation threshold of the rear duct can be increased, improving the system's propulsion performance. This aerodynamically coupled layout design enhances the propulsion performance of the novel propulsion system, reduces energy loss, and thus helps the eVTOL aircraft achieve efficient, long-endurance flight, meeting the needs of cruise flight and other multi-mission scenarios.

[0061] The specific structure of the aircraft's lift component 10 will be further disclosed below with reference to the accompanying drawings.

[0062] The aircraft lift component 10 includes an wing skin (not shown), an external wing spars 11, flaps 12, multiple wing ribs 13, and multiple transverse wing spars 14.

[0063] The front ends of multiple wing ribs 13 are fixedly connected to the outer wing spars 11; multiple wing ribs 13 are fixedly connected to multiple transverse wing spars 14. The multiple wing ribs 13 are arranged in parallel.

[0064] The specific structures of the first regulating mechanism 40 and the second regulating mechanism 50 will be further disclosed below with reference to the accompanying drawings.

[0065] Both the first adjustment mechanism 40 and the second adjustment mechanism 50 include a drive motor 41 and a rotating shaft 42.

[0066] A driven gear 43 is provided on the rotating shaft 42, and a driving gear 44 is provided on the output shaft of the drive motor 41. The driving gear 44 meshes with the driven gear 43.

[0067] The pivot 42 is rotatably connected to the wing rib 13, and the mounting base 24 is fixedly connected to the pivot 42; the wing skin has an opening for the mounting base 24 to extend to the outside, and to meet the movement requirements of the mounting base 24.

[0068] The drive motor 41 is fixedly mounted on the rib 13.

[0069] The flap 12 is fixedly connected to the rotating shaft 42 of the second adjustment mechanism 50, and the flap 12 rotates with the rotating shaft 42 of the second adjustment mechanism 50.

[0070] Although embodiments of this application have been shown and described above, the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be conceived without inventive effort should be covered within the scope of protection of this invention. Unless expressly stated otherwise, no element, action or instruction used herein should be construed as critical or necessary.

Claims

1. A dual-row ducted fan efficiency-enhancing power system, characterized in that, include: Lifting components of an aircraft, used to generate upward lift when moving forward; Multiple front-ducted fans are used to provide thrust for the lift components of the aircraft; as well as Multiple ducted fans are used to provide thrust for the lift components of the aircraft; Among them, multiple front ducted fans and multiple rear ducted fans are all disposed on the upper surface of the aircraft's lift component; The multiple front duct fans are also used in conjunction with the multiple rear duct fans to generate lift by utilizing jet flow and suction effects.

2. The dual-row ducted fan efficiency-enhancing power system according to claim 1, characterized in that, The front ducted fan and the rear ducted fan are arranged forward and backward along the chord of the aircraft's lift component, and there is a chordal distance segment between the front ducted fan and the rear ducted fan, which serves as an airflow guiding surface. The airflow guiding surface is used to ensure that the high-speed jet generated by the front ducted fan is fully coupled with the upper surface of the aircraft's lifting component before reaching the air intake area of ​​the rear ducted fan, thereby injecting momentum into the upper surface of the aircraft's lifting component to increase airflow speed and improve the air intake conditions of the rear ducted fan.

3. The dual-row ducted fan efficiency-enhancing power system according to claim 1, characterized in that, Also includes: The first adjustment mechanism is used to regulate the jet direction of the front duct fan; The first adjustment mechanism is disposed on the lift component of the aircraft.

4. The dual-row ducted fan efficiency-enhancing power system according to claim 1, characterized in that, Also includes: The second adjustment mechanism is used to control the jet direction of the rear duct fan; The second adjustment mechanism is configured on the aircraft's lift component.

5. The dual-row ducted fan efficiency-enhancing power system according to claim 1, characterized in that, The arrangement of the front ducted fan and the rear ducted fan in the spanwise direction of the aircraft's lift components can be one of the following: array arrangement, one-to-one correspondence arrangement, staggered arrangement, interleaved arrangement, equal spacing arrangement, or non-equal spacing arrangement.

6. The dual-row ducted fan efficiency-enhancing power system according to claim 1, characterized in that, The jet direction of the front ducted fan is toward the rear region of the upper surface of the aircraft's lifting component. The air intake direction of the rear ducted fan is toward the jet development area of ​​the front ducted fan or the airflow guide surface.

7. The dual-row ducted fan efficiency-enhancing power system according to claim 4, characterized in that, The aircraft's lifting components are equipped with flaps; The second adjustment mechanism is also used to adjust the angle of the flap.

8. The dual-row ducted fan efficiency-enhancing power system according to claim 7, characterized in that, The flaps are configured to move in conjunction with the rear ducted fan.

9. The dual-row ducted fan efficiency-enhancing power system according to claim 1, characterized in that, The lifting components of the aircraft are one of the following: fuselage, straight wing, swept wing, forward swept wing, folding wing, variable chord length wing, blended wing-body structure, canard, ring wing, compound wing, or distributed lifting body structure.

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