Nacelle unit, distributed propulsion nacelle and new energy aircraft

Abstract

The utility model relates to a short cabin unit, a distributed propulsion short cabin and a new energy aircraft. The short cabin unit comprises an air inlet section, an exhaust section and a ducted fan, the ducted fan is arranged between the air inlet section and the exhaust section; the air inlet section is a non-rotary body, and the air exhaust section is a rotary body; the nacelle is designed in a sinking mode, and the sinking mode is achieved in the mode that the distance between a rotating shaft of a ducted fan and a lower lip opening of an air inlet section in the longitudinal direction is smaller than the radius of the ducted fan. And a diffusion section is formed below the air inlet section. According to the nacelle design, the windward area of the nacelle is properly reduced, so that the design flow of the nacelle is matched with the flow of the upper surface of a wing under the cruise working condition, the adverse effect of a front high-pressure area on the wing caused by overflow of the nacelle is weakened, meanwhile, the pressure difference resistance of the front and the rear of the nacelle is weakened, and pneumatic matching is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of nacelle design technology, specifically relating to a nacelle unit, a distributed propulsion nacelle, and a new energy aircraft. Background Technology

[0002] With the public paying increasing attention to environmental protection, society has put forward green development requirements for the rapidly growing aviation industry. Meanwhile, the rapid progress of new energy underlying technologies has made it possible to develop medium and large new energy manned aircraft driven by electric power (i.e., electric propulsion).

[0003] Unlike traditional aero engines, which first convert chemical energy into internal energy and then use that internal energy to generate thrust, electric propulsion systems directly generate thrust using input electrical energy. This simplified thrust generation method reduces design constraints on electric propulsion systems, allowing for more flexible power configurations. One efficient propulsion configuration is distributed propulsion. Distributed propulsion is a relatively new power layout approach in aircraft design. This configuration uses an array of multiple small ducted fans arranged close to the wing (or fuselage) to utilize boundary layer suction, thereby improving propulsion efficiency.

[0004] Because the ducted fans are positioned close to the wing, the distributed nacelles that provide air intake and exhaust for the ducted fans form a strong aerodynamic coupling with the wing. To ensure excellent aerodynamic performance across all flight conditions, the aerodynamic design of the distributed nacelles surrounding the engine array needs to be optimized. If traditional design methods are simply used to obtain the nacelles and place them on the wing, the free airflow in front during cruise will be decelerated and pressurized, forming a low-speed, high-pressure airflow before the distributed nacelle intake. This airflow will disrupt the high-speed, low-pressure flow field on the wing surface, resulting in reduced lift and increased drag, severely impacting the overall aerodynamic performance of the aircraft. Furthermore, maintainability must be considered in the actual use of the aircraft, especially in the context of medium to large-sized aircraft. Utility Model Content

[0005] In order to overcome the problems existing in the prior art, this utility model provides a nacelle unit, a distributed propulsion nacelle, and a new energy aircraft to overcome the current defects.

[0006] A nacelle unit for a new energy aircraft, the nacelle unit comprising: an air intake section, an exhaust section, and a ducted fan;

[0007] The ducted fan is located between the intake section and the exhaust section;

[0008] The intake section is a non-rotating body, and the exhaust section is a rotating body;

[0009] The nacelle is of a sunken type, which is achieved by making the longitudinal distance between the shaft of the ducted fan and the lower lip of the air intake section smaller than the radius of the ducted fan.

[0010] A diffuser section is formed below the intake section.

[0011] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the ducted fan includes a rotor, a stator, a fan housing, and a motor, wherein the rotor is connected to the shaft of the motor; one end of the stator is connected to the fan housing, and the other end is connected to the housing of the motor.

[0012] In addition to the aspects described above and any possible implementation, a further implementation is provided that includes a tail cone connected to the motor, which together with the exhaust section forms a jet surface to generate maximum thrust.

[0013] This utility model also provides a distributed propulsion nacelle, which includes several detachable nacelle units arranged in parallel.

[0014] In addition to the aspects described above and any possible implementation, a further implementation is provided in which each distributed propulsion nacelle comprises 2 to 8 nacelle units.

[0015] In addition to the aspects described above and any possible implementation, a further implementation is provided in which each of the distributed propulsion nacelles further includes an exhaust after-rectification section, each of the nacelle units including a circular cross-section formed by the exhaust section, the exhaust after-rectification section being disposed in a triangular region between the respective circular cross-sections.

[0016] This utility model also provides a new energy aircraft, which includes a fuselage, wings and the distributed propulsion nacelle, with the wings disposed on the left and right sides of the fuselage and the distributed propulsion nacelle disposed on the wings.

[0017] In addition to the aspects and any possible implementations described above, a further implementation is provided in which two sets of the distributed propulsion nacelles are provided, each set being mounted on a wing near the fuselage.

[0018] In addition to the aspects and any possible implementations described above, a further implementation is provided in which each of the distributed propulsion nacelles adopts a modular design, that is, it is composed of the innermost nacelle unit and the outermost nacelle unit arranged along the wing span.

[0019] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the innermost nacelle unit and the outermost nacelle unit have different external shapes.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This utility model discloses a nacelle unit for use in a new energy aircraft. The nacelle unit includes: an air intake section, an exhaust section, and a ducted fan; the ducted fan is disposed between the air intake section and the exhaust section.

[0022] The air intake section is a non-rotating body, while the exhaust section is a rotating body. The nacelle adopts a sunken design, achieved by ensuring that the longitudinal distance between the ducted fan's shaft and the lower lip of the air intake section is less than the radius of the ducted fan. A diffuser section is formed below the air intake section. This sunken nacelle design appropriately reduces the nacelle's frontal area, allowing the nacelle's design flow rate to match the flow rate on the upper surface of the wing during cruise conditions. This reduces the adverse effects of the high-pressure area ahead of the nacelle caused by overflow on the wing, and simultaneously reduces the pressure drag before and after the nacelle, achieving aerodynamic matching. In terms of configuration, the distributed nacelle design allows each unit to be independently detached, facilitating targeted maintenance and inspection by ground personnel, shortening maintenance time, and improving economy. This invention can be used in new energy aircraft using distributed electric propulsion, providing high-quality air intake and exhaust for the distributed power unit with minimal drag. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the installation of the distributed nacelle of this utility model;

[0024] Figure 2 This is a cross-sectional view of the distributed nacelle of this utility model in its installed state. Detailed Implementation

[0025] To better understand the technical solution of this utility model, the content of this utility model includes, but is not limited to, the specific embodiments described below. Similar technologies and methods should be considered within the scope of protection of this utility model. To make the technical problem to be solved, the technical solution, and the advantages of this utility model clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0026] It should be understood that the embodiments described in this utility model are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] This utility model provides a nacelle unit for new energy aircraft, the nacelle unit comprising: an air intake section, an exhaust section, and a ducted fan;

[0028] The ducted fan is located between the intake section and the exhaust section;

[0029] The intake section is a non-rotating body, and the exhaust section is a rotating body;

[0030] The nacelle is of a sunken type, which is achieved by making the longitudinal distance between the shaft of the ducted fan and the lower lip of the air intake section smaller than the radius of the ducted fan.

[0031] A diffuser section is formed below the intake section.

[0032] Furthermore, the ducted fan includes a rotor, a stator, a fan housing, and a motor, wherein the rotor is connected to the shaft of the motor; one end of the stator is connected to the fan housing, and the other end is connected to the housing of the motor.

[0033] Furthermore, it also includes a tail cone connected to the motor, which together with the exhaust section forms a jet surface to generate maximum thrust.

[0034] As an embodiment of the present invention, the present invention also provides a distributed propulsion nacelle, which includes several detachable nacelle units arranged in parallel.

[0035] Furthermore, each distributed propulsion nacelle comprises 2 to 8 nacelle units.

[0036] Furthermore, each of the distributed propulsion nacelles also includes an exhaust post-rectification section, and each nacelle unit includes a circular cross-section formed by the exhaust section, with the exhaust post-rectification section disposed in a triangular area between the various circular cross-sections.

[0037] As an embodiment of the present invention, the present invention also provides a new energy aircraft, the aircraft including a fuselage, wings and the distributed propulsion nacelle, the wings being disposed on the left and right sides of the fuselage, and the distributed propulsion nacelle being disposed on the wings.

[0038] Furthermore, there are two sets of the distributed propulsion nacelles, each set being installed on the wing near the fuselage.

[0039] Furthermore, each of the distributed propulsion nacelles adopts a modular design, that is, it is composed of the innermost nacelle unit and the outermost nacelle unit arranged along the wing span.

[0040] Furthermore, the innermost nacelle unit and the outermost nacelle unit have different external shapes.

[0041] Specifically, such as Figure 1As shown, the distributed nacelle 3 is divided into two sets, left and right, respectively installed on the inner side of the main wing (non-flaps) of the left and right wings 2, near the fuselage 1. Each set of distributed nacelles 3 consists of no less than two and no more than eight nacelle units 4. Except for the nacelle unit closest to the wingtip, the other nacelle units are geometrically identical. The outermost nacelle unit is aerodynamically modified based on the shape of the inner nacelle to improve performance, but retains the inner flow surface (including the nacelle air intake section 5, ducted fan casing 6, and nacelle exhaust section 7, see...). Figure 2 The internal aerodynamic performance of the nacelle is consistent with that of the inner nacelle, thus ensuring that its intake and exhaust aerodynamic performance is consistent with that of the inner nacelle, which helps to simplify the design of the distributed power system. Each distributed nacelle 3 adopts a modular design, that is, it is composed of inner nacelle units and outermost nacelles arranged along the wing span. In order to facilitate ground maintenance and improve economic efficiency, each nacelle unit 4 of the distributed nacelle 3 can be independently disassembled and assembled. Figure 1 The left side shows the installed state of the distributed nacelles, and the right side shows the state of the middle nacelle unit 4 being independently removed.

[0042] Figure 2 Showing Figure 1 A cross-sectional view of the ducted fan in its installed state. This duct unit houses a ducted fan, comprising a fan rotor 11, a stator 12, a fan housing 6, and a motor 14. The fan rotor 11 is connected to the shaft of the motor 14. One end of the stator 12 is connected to the fan housing 6, and the other end is connected to the housing of the motor 14. The fan housing 6 is connected to the wing structure via appropriate mechanical connections (such as mounting joints). The fan rotor 11 performs work on the airflow, increasing the total air pressure. The stator 12 rectifies the airflow behind the rotor, changing the swirling airflow into airflow along the motor axis, thus increasing thrust. The fan housing 6 provides an inner flow surface, encloses the inner flow channel, and structurally meets the rotor containment requirements. The duct unit provides the ducted fan with an intake section 5, an exhaust section 7, and a post-exhaust rectification section 8. The nacelle unit's intake section 5 is a non-rotating body, which allows for the transition of airflow from the non-circular intake cross-section of the distributed propulsion nacelle unit to the circular cross-section of the ducted fan. The exhaust section 7, however, is a rotating body, generating thrust with minimal loss. The rotating shaft is the fan's shaft 13. According to... Figure 1 As can be seen, since each nacelle unit has at least one adjacent unit, a triangular region exists between the circular cross-sections of adjacent exhaust nozzles. The exhaust post-rectifier 8 is used to fill this region, eliminating flow separation downstream of the nacelle exhaust to reduce drag. Figure 2 As shown, it also includes a tail cone 9, which, together with the exhaust section, forms an appropriate jet area to generate maximum thrust. The tail cone 9 is directly connected to the motor 14.

[0043] Because aircraft have different flight speeds and thrust requirements within their flight envelope, ducted fans will have correspondingly different intake flow requirements. The distributed nacelle needs to provide a stable, high-quality intake airflow for the ducted fan under typical operating conditions, with its intake flow coefficient varying between greater than 1 at low speeds and less than 1 at high speeds. To mitigate the adverse effects of an intake flow coefficient less than 1 at high speeds on the overall aerodynamic characteristics of the aircraft, the distributed nacelle adopts a recessed design, meaning the distance in the y-direction (x-direction is the fan axis, and y-direction is the direction perpendicular to x within the nacelle's symmetry plane; this direction is defined only for ease of description) between the ducted fan shaft 13 and the lower intake lip 10 is less than the ducted fan radius. For the intake airflow, the intake section 5 forms a diffuser section along the fan axis to decelerate and pressurize the airflow, providing the fan with an appropriate inflow.

[0044] The design process of this utility model for an independently detachable, sunken, distributed propulsion nacelle is as follows:

[0045] 1) Determine the reasonable outer envelope of the distributed nacelle based on the selected ducted fan geometry, and decompose it into nacelle units with consistent axial length, longitudinal height and span width for design, specifically including intake section design, exhaust section design, external flow profile design and exhaust rectification design;

[0046] 2) Using computational fluid dynamics (CFD) calculations, the overflow flow rate of the nacelle under design conditions is analyzed. Based on this analysis, the downward displacement of the distributed nacelle is adjusted to ensure that the intake flow coefficient is greater than 0.8, thereby reducing overflow drag and interference drag. A diffuser section is formed below intake section 5 in the xy plane. For aircraft with flight speeds greater than Mach 0.25, the average expansion angle of the downward-displaced nacelle intake section is not less than 3° to ensure drag reduction. The expansion angle is the angle between the line connecting the front and rear endpoints of the lower contour line of intake section 5 and the x-axis. Figure 2 As shown in α; the internal flow profile of the rotating exhaust section 7 of the nacelle unit is designed as needed to ensure that the outlet cross-sectional area meets the design requirements and that the cross-sectional area changes uniformly to reduce flow loss. The exhaust rectification 8 between the circular nozzles (exit cross-section in the x direction) of the motor 14 exhaust is used to eliminate flow separation.

[0047] 3) To ensure that the distributed nacelle has good working conditions, the wing 2 that works with it is designed with curved surfaces to ensure that the curved surface of the lower lip 10 of the air intake section 5 is tangent to the surface of the wing 2 at the same position in space, so as to ensure smooth airflow.

[0048] 4) Repeat steps 2), 3), and 4) until the ideal internal flow aerodynamic characteristics are obtained. These characteristics include the inlet total pressure recovery coefficient, inlet distortion, exhaust total pressure recovery, exhaust thrust coefficient, exhaust flow coefficient, and external flow aerodynamic characteristics (overall drag coefficient), ultimately achieving a nacelle aerodynamic design that meets the requirements.

[0049] In summary, in terms of configuration, existing designs use distributed nacelles arranged as two integrated units on the left and right sides, meaning that each nacelle cannot be independently disassembled and assembled. While this does not affect aerodynamic performance, it leads to maintenance difficulties during use. This invention, however, adopts a modular design for each distributed nacelle, consisting of an inner nacelle unit and an outermost nacelle arranged along the wing span, allowing each nacelle unit to be independently disassembled and assembled.

[0050] In terms of aerodynamics, existing technology employs a non-sinking nacelle design. In existing technology, "non-sinking" refers to the height in the y-direction from the lower lip opening 10 to the ducted fan shaft (see...). Figure 2 The ducted fan's radius is the same as the fan's radius. Such a design results in a large frontal area for the distributed nacelles designed for high-speed operation, significantly affecting the wing's airflow field and reducing the overall aerodynamic performance of the aircraft. This invention, however, adopts a recessed design for the distributed nacelles, meaning the distance in the y-direction between the ducted fan shaft and the lower lip of the air intake is less than the ducted fan's radius.

[0051] The terminology used in the embodiments of this utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The singular forms “a,” “the,” and “the” used in the embodiments of this utility model and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0052] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or related technical or knowledge. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be protected within the scope of the appended claims.

Claims

1. A nacelle unit for use in a new energy aircraft, characterized in that, The nacelle unit includes: an intake section, an exhaust section, and a ducted fan; The ducted fan is located between the intake section and the exhaust section; The intake section is a non-rotating body, and the exhaust section is a rotating body; The nacelle is of a sunken type, which is achieved by making the longitudinal distance between the shaft of the ducted fan and the lower lip of the air intake section smaller than the radius of the ducted fan. A diffuser section is formed below the intake section.

2. The nacelle unit according to claim 1, characterized in that, The ducted fan includes a rotor, a stator, a fan housing, and a motor, wherein the rotor is connected to the shaft of the motor; one end of the stator is connected to the fan housing, and the other end is connected to the housing of the motor.

3. The nacelle unit according to claim 1, characterized in that, It also includes a tail cone connected to the motor, which together with the exhaust section forms a jet surface to generate maximum thrust.

4. A distributed propulsion nacelle, characterized in that, The distributed propulsion nacelle comprises several detachable nacelle units arranged side-by-side as described in any one of claims 1-3.

5. The distributed propulsion nacelle according to claim 4, characterized in that, Each distributed propulsion nacelle consists of 2 to 8 nacelle units.

6. The distributed propulsion nacelle according to claim 4, characterized in that, Each of the distributed propulsion nacelles also includes an exhaust after-rectification section, and each nacelle unit includes a circular cross-section formed by the exhaust section, with the exhaust after-rectification section disposed in a triangular area between the various circular cross-sections.

7. A new energy aircraft, characterized in that, The aircraft includes a fuselage, wings, and a distributed propulsion nacelle as described in any one of claims 4-6, wherein the wings are disposed on the left and right sides of the fuselage, and the distributed propulsion nacelle is disposed on the wings.

8. The new energy aircraft according to claim 7, characterized in that, There are two sets of the distributed propulsion nacelles, each set is installed on the wing near the fuselage.

9. The new energy aircraft according to claim 7, characterized in that, Each of the distributed propulsion nacelles adopts a modular design, that is, it is composed of the innermost nacelle unit and the outermost nacelle unit arranged along the wing span.

10. The new energy aircraft according to claim 9, characterized in that, The innermost nacelle unit and the outermost nacelle unit have different shapes.

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