Embedded air intake structure and aircraft

Abstract

This invention provides an embedded air intake structure, relating to the field of flight equipment. It includes an air intake body with a bottom wall and an air inlet. The bottom wall of the air intake body is fixedly connected to the trailing edge of an aircraft wing. The upper surface of the bottom wall of the air intake body is streamlined, allowing for a smooth transition with the upper surface of the wing. The opening of the air intake body near the wing end serves as the air inlet. When the aircraft is in horizontal flight, the air inlet is located above the bottom wall of the air intake body and below the highest point of the upper surface of the wing. This invention also provides an aircraft, including a wing, a fuselage, and the aforementioned embedded air intake structure. The bottom wall of the air intake body is fixedly connected to the trailing edge of the wing, and the wing is fixedly connected to the fuselage. The embedded air intake structure and aircraft provided by this invention can improve air intake efficiency, reduce strong radar echoes, and improve radar stealth performance.

Description

Technical Field

[0001] This invention relates to the field of flight equipment technology, and in particular to an embedded air intake structure and an aircraft. Background Technology

[0002] Tiltrotor aircraft are a new type of aircraft that integrates the characteristics of fixed-wing aircraft and helicopters. Due to their ability to take off and land vertically and fly at high speeds, tiltrotor aircraft are widely used and possess significant military value. To counter increasingly advanced radar detection technologies on the battlefield, tiltrotor aircraft need radar stealth design to improve their survivability. Radar Cross Section (RCS) is an important indicator for evaluating radar stealth performance. It is a physical quantity that characterizes the intensity of the echo generated by a target under radar illumination. The lower the RCS, the less likely the target is to be detected by enemy radar, and the higher its survivability.

[0003] Currently, the air intakes of tiltrotor aircraft are mostly exposed on the outside of the fuselage, such as the V-22 tiltrotor, V-280 tiltrotor, XV-15 tiltrotor, and Hawkeye tiltrotor UAV; specifically, such as Figure 1 As shown, the existing air intake is located at the top of the wing, and the air inlet of the air intake is higher than the highest point of the upper surface of the wing. As a cavity structure, the air intake of the tiltrotor engine, when exposed, can improve air intake efficiency, but radar waves can easily enter its interior, causing multiple reflections and generating strong radar echoes, which is detrimental to radar stealth. Summary of the Invention

[0004] The purpose of this invention is to provide an embedded air intake structure and aircraft to solve the problems existing in the prior art, thereby improving air intake efficiency, reducing strong radar echoes, and improving radar stealth performance.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides an embedded air intake structure, including an air intake body having a bottom wall and an air inlet. The bottom wall of the air intake body is used to be fixedly connected to the trailing edge of an aircraft wing. The upper surface of the bottom wall of the air intake body is streamlined and can smoothly connect and transition with the upper surface of the aircraft wing. The opening of the air intake body near one end of the aircraft wing is the air inlet. When the aircraft is flying horizontally, the air inlet is located above the bottom wall of the air intake body and below the highest point of the upper surface of the aircraft wing.

[0007] Preferably, it also includes a grille, which is fixedly connected to the air inlet of the air intake body and can cover the air inlet.

[0008] Preferably, it further includes an exposed bottom wall and two exposed side walls. The exposed bottom wall extends from the lower edge of the air inlet toward one end near the leading edge of the wing. The exposed bottom wall is integrally formed with the bottom wall of the air inlet body as a connecting wall. The upper surface of the connecting wall is streamlined. The exposed bottom wall is used to fit and fix to the upper surface of the wing near its own trailing edge. The upper surface of the exposed bottom wall can smoothly transition with the upper surface of the wing. The air inlet body is located on the side of the wing trailing edge away from the wing. The two exposed side walls are respectively fixedly connected to the exposed bottom wall on both sides of the wing in the length direction and extend toward one end near the top surface of the air inlet body.

[0009] Preferably, the grille is inclined from one end of the exposed bottom wall near the trailing edge of the wing to the side away from the trailing edge of the wing.

[0010] Preferably, each of the exposed sidewalls is perpendicular to the length direction of the wing.

[0011] The present invention also provides an aircraft, including a wing, a fuselage and the above-mentioned embedded air intake structure, wherein the bottom wall of the air intake body is fixedly connected to the trailing edge of the wing, and the wing is fixedly connected to the fuselage.

[0012] Preferably, the air intake body is integrally formed with the wing.

[0013] Preferably, the wing is detachably fixed to the fuselage.

[0014] The present invention achieves the following technical effects compared to the prior art:

[0015] The embedded air intake structure and aircraft provided by this invention have a streamlined upper surface of the bottom wall of the air intake body. The upper surface of the bottom wall of the air intake body can connect and smoothly transition with the upper surface of the wing. When the aircraft is flying horizontally, the air intake is located above the bottom wall of the air intake body. Therefore, when the aircraft is flying, the airflow can enter the cavity of the air intake body along the streamlined upper surface of the wing and the bottom wall of the air intake body. The smoothly transitioned upper surface and the upper surface of the bottom wall of the air intake body can effectively guide the airflow. Moreover, the air intake is located above the bottom wall of the air intake body, which is conducive to the entry of airflow, thus improving the intake efficiency. When the aircraft is flying horizontally, the part of the air intake away from the bottom wall of the air intake body is lower than the highest point of the upper surface of the wing. Some radar waves can be blocked by the part of the upper surface of the wing that is higher than the air intake, making it difficult for radar waves to enter the inner cavity of the air intake body, thereby reducing strong radar echoes and improving radar stealth performance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0017] Figure 1 This is a schematic diagram of the existing air intake structure;

[0018] Figure 2 This is a schematic diagram of the installation of the embedded air intake structure in Example 1;

[0019] Figure 3 This is a schematic diagram of the embedded air intake structure in Example 1;

[0020] Figure 4 This is a front view of the embedded air intake structure in Example 1;

[0021] Figure 5 This is a top view of the embedded air intake structure in Example 1;

[0022] Figure 6 This is a cross-sectional view of the embedded air intake structure in Example 1 after it is installed on the wing, showing the wing and the embedded air intake structure at the plane of symmetry of the fuselage.

[0023] Figure 7 This is a schematic diagram of the air intake structure of the embedded air intake duct in Example 1.

[0024] Figure 8 This is a schematic diagram of the aircraft structure in Example 2;

[0025] Figure 9 This is a schematic diagram of the fuselage structure in Example 2;

[0026] Figure 10 This is a schematic diagram of the installation of the air intake body, the wing, and the connecting components integrally formed in Embodiment 2 with the fuselage;

[0027] Figure 11 The graphs show the RCS values ​​of the tiltrotor aircraft with an embedded air intake structure at 3GHz in Example 1 and the RCS values ​​of the conventional tiltrotor aircraft with an exposed air intake structure.

[0028] Figure 12 The RCS curves for the 6GHz tiltrotor aircraft with an embedded air intake structure in Example 1 and the RCS curves for the conventional tiltrotor aircraft with an exposed air intake structure are shown.

[0029] Figure 13The graphs show the RCS values ​​of the tiltrotor aircraft with an embedded air intake structure at 10 GHz in Example 1 and the RCS values ​​of the conventional tiltrotor aircraft with an exposed air intake structure.

[0030] In the diagram: 100, embedded air intake structure; 200, aircraft; 1, air intake body; 101, bottom wall; 102, air intake; 103, wing; 2, grille; 3, exposed bottom wall; 4, exposed side wall; 5, fuselage; 6, rotor; 7, existing air intake. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0032] The purpose of this invention is to provide an embedded air intake structure and aircraft to solve the problems existing in the prior art, thereby improving air intake efficiency, reducing strong radar echoes, and improving radar stealth performance.

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] like Figure 2-7As shown, this embodiment provides an embedded air intake structure 100, including an air intake body 1. The air intake body 1 has a bottom wall 101 and an air intake 102. The bottom wall 101 of the air intake body 1 is used to be fixedly connected to the trailing edge of the wing 103. The upper surface of the bottom wall 101 of the air intake body 1 is streamlined. The upper surface of the bottom wall 101 of the air intake body 1 can connect and smoothly transition with the upper surface of the wing 103. The opening of the air intake body 1 near the end of the wing 103 is the air intake 102. When the aircraft 200 is flying horizontally, the air intake 102 is located above the bottom wall 101 of the air intake body 1 and below the highest point of the upper surface of the wing 103. When the aircraft 200 is in flight, the airflow can enter the cavity of the air intake body 1 along the streamlined upper surface of the wing 103 and the bottom wall 101 of the air intake body 1. The smooth transition of the upper surface and the upper surface of the bottom wall 101 of the air intake body 1 can effectively guide the airflow. Moreover, the air intake 102 is located above the bottom wall 101 of the air intake body 1, which is conducive to the airflow entering, thus improving the intake efficiency. When the aircraft 200 is in horizontal flight, the part of the air intake 102 that is far from the bottom wall 101 of the air intake body 1 is lower than the highest point of the upper surface of the wing 103. Some radar waves can be blocked by the part of the upper surface of the wing 103 that is higher than the air intake 102, making it difficult for radar waves to enter the cavity of the air intake body 1, thereby reducing radar echo and improving radar stealth performance.

[0036] The embedded air intake structure 100 provided in this embodiment also includes a grille 2, which is fixedly connected to the air intake 102 of the air intake body 1 and can cover the air intake 102. The grille 2 is designed to reduce radar wave reflection and further improve radar stealth performance. As a preferred embodiment, the grille 2 is made of the same material as the surface of the fuselage 5.

[0037] The embedded air intake structure 100 provided in this embodiment also includes an exposed bottom wall 3 and two exposed side walls 4. The exposed bottom wall 3 extends from the lower edge of the air intake 102 towards the end near the leading edge of the wing 103. The exposed bottom wall 3 and the bottom wall 101 of the air intake body 1 are integrally formed as a connecting wall. The upper surface of the connecting wall is streamlined. The exposed bottom wall 3 is used to fit and fix to the upper surface of the end of the wing 103 near its own trailing edge. The upper surface of the exposed bottom wall 3 can smoothly transition with the upper surface of the wing 103. The air intake body 1 is disposed on the wing 1. The trailing edge of 03 is away from the side of wing 103, so that the upper surface of wing 103 can be completely exposed without being blocked by the air intake body 1, which reduces the drag of fuselage 5; at the same time, since the upper surface of wing 103 is used as the upper surface of aircraft 200, a pressure difference can be formed between the upper surface of wing 103 and the flat lower surface of fuselage, providing a certain lift and improving flight performance; the two exposed sidewalls 4 are respectively fixedly connected to the exposed bottom wall 3 on both sides of the length direction of wing 103 and extend towards the end close to the top surface of air intake body 1.

[0038] As a preferred embodiment, such as Figure 6-7 As shown, the upper surface of the connecting wall and the upper surface of the wing 103 have the same streamlined shape. That is, the streamlined direction of the upper surface of the exposed bottom wall 3 and the part of the upper surface of the wing 103 that is in close contact with itself is exactly the same. The upper surface of the bottom wall 101 of the air intake body 1 is an extension of the upper surface of the exposed bottom wall 3. The upper surface of the wing 103 and the upper surface of the connecting wall are generally streamlined. This allows the incoming airflow to enter the air intake 102 better, thereby improving the intake efficiency.

[0039] In a preferred embodiment, the grille 2 is inclined from the end of the exposed bottom wall 3 near the trailing edge of the wing 103 toward the side away from the trailing edge of the wing 103. This reduces the probability of radar waves hitting the grille vertically, decreases the vertical specular reflection of radar waves, reduces the radar cross-section, and achieves better stealth performance. More preferably, the lower end of the grille 2 is located at or behind the trailing edge of the wing 103, and the upper end of the grille 2 extends toward the rear and upper part of the trailing edge of the wing 103.

[0040] In a preferred embodiment, the top surface, side surface and exposed sidewall 4 of the air intake body 1 are all planar. When radar waves irradiate the planar structure, their reflection path satisfies the principle of specular reflection. The radar waves are reflected along the symmetrical surface to the side away from the radar transmitter, which can concentrate the reflected radar waves in a direction away from the receiving radar, reducing the probability of being received by the receiving radar, so as to achieve the stealth effect.

[0041] In a preferred embodiment, each exposed sidewall 4 is perpendicular to the length direction of the wing 103.

[0042] To illustrate the impact of this structure on radar stealth performance, two tiltrotor 6-plane models were established: one using a conventional exposed air intake structure (existing air intake 7) and the other using the tiltrotor 6-plane model in this embodiment. The pitch and roll angles of the fuselage 5 were both 0°. Their RCS (Radar Cross Section) was calculated within a horizontal range of -60° to 60°, in 1° increments. The nose direction was defined as pointing 0°, with negative angles representing the right side of the fuselage 5 and positive angles representing the left side. According to the statistical probability table in Table 1 showing the proportion of bands used by commonly used detection radars, among the four types of radars listed, 88.7% use the S-band, 82.8% use the C-band, and 82.1% use the X-band. The S, C, and X bands are the most commonly used; therefore, the center frequencies of these three bands, 3GHz, 6GHz, and 10GHz, were used as the radar operating frequencies, and the radar is vertically polarized. The calculation results are shown in [Table 1]. Figure 11-13The calculation results show that, in most calculation angle domains, the RCS of the tiltrotor 6 aircraft equipped with the embedded air intake structure 100 provided in this embodiment is significantly lower than that of the conventional tiltrotor 6 aircraft with an exposed air intake structure, especially in the angle domains of -60° to -30° and 30° to 60°. Considering all calculation conditions, at 3 GHz, the average RCS of the 100-type tiltrotor aircraft with an embedded air intake structure is 1.55 dB lower than that of the conventional tiltrotor aircraft with an exposed air intake structure; at 6 GHz, the average RCS of the 100-type tiltrotor aircraft with an embedded air intake structure is 2.05 dB lower than that of the conventional tiltrotor aircraft with an exposed air intake structure; and at 10 GHz, the average RCS of the 100-type tiltrotor aircraft with an embedded air intake structure is 1.93 dB lower than that of the conventional tiltrotor aircraft with an exposed air intake structure. Therefore, the tiltrotor aircraft using the structure of this embodiment has a good RCS reduction effect.

[0043] Table 1. Statistical probability table of the proportion of wavebands used by commonly used detection radars.

[0044]

[0045] Example 2

[0046] like Figure 8-10 As shown, this embodiment provides an aircraft 200, including a wing 103, a fuselage 5, and an embedded air intake structure 100 as in Embodiment 1. The bottom wall 101 of the air intake body 1 is fixedly connected to the trailing edge of the wing 103, and the wing 103 is fixedly connected to the fuselage 5.

[0047] As a preferred embodiment, the air intake body 1 and the wing 103 are integrally formed. More preferably, the upper surface of the wing 103 can be used as the exposed bottom surface 3; this helps to reduce the number of process steps and facilitates disassembly and assembly.

[0048] The wing 103 is detachably and fixedly connected to the fuselage 5. In a preferred embodiment, the aircraft 200 provided in this embodiment also includes a connecting component. The top of the connecting component has a groove, and the wing 103 is disposed within the groove. In a more preferred embodiment, the air intake body 1, the wing 103, and the connecting component are integrally formed. The top of the fuselage 5 has a mounting groove. The structure, after the air intake body 1, the wing 103, and the connecting component are integrally formed, is located on the top of the tiltrotor 6 in the form of a hatch and is riveted to the fuselage 5 through the mounting groove, reducing process and assembly steps and facilitating overall disassembly and maintenance. The connecting component contains a space for accommodating a mechanical transmission device.

[0049] In a preferred embodiment, a rotor 6 is provided at each end of the wing 103.

[0050] In this embodiment, the aircraft 200 is preferably a tiltrotor aircraft, but it can also be a helicopter or other aircraft 200 with radar stealth requirements.

[0051] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An embedded air intake structure, characterized in that: The system includes an air intake body, which has a bottom wall and an air inlet. The bottom wall of the air intake body is used to be fixedly connected to the trailing edge of the wing. The upper surface of the bottom wall of the air intake body is streamlined and can smoothly connect with the upper surface of the wing. The opening of the air intake body near one end of the wing is the air inlet. When the aircraft is flying horizontally, the air inlet is located above the bottom wall of the air intake body and below the highest point of the upper surface of the wing.

2. The embedded air intake structure according to claim 1, characterized in that: It also includes a grille, which is fixedly connected to the air inlet of the air intake body and can cover the air inlet.

3. The embedded air intake structure according to claim 2, characterized in that: It also includes an exposed bottom wall and two exposed side walls. The exposed bottom wall extends from the lower edge of the air intake towards the end near the leading edge of the wing. The exposed bottom wall is integrally formed with the bottom wall of the air intake body as a connecting wall. The upper surface of the connecting wall is streamlined. The exposed bottom wall is used to fit and fix to the upper surface of the end of the wing near its own trailing edge. The upper surface of the exposed bottom wall can smoothly transition with the upper surface of the wing. The air intake body is located on the side of the wing's trailing edge away from the wing. The two exposed side walls are respectively fixedly connected to the exposed bottom wall on both sides of the wing's length direction and extend towards the end near the top surface of the air intake body.

4. The embedded air intake structure according to claim 3, characterized in that: The grille is inclined from one end of the exposed bottom wall near the trailing edge of the wing to the side away from the trailing edge of the wing.

5. The embedded air intake structure according to claim 4, characterized in that: Each of the exposed sidewalls is perpendicular to the length direction of the wing.

6. An aircraft, characterized in that: The system includes a wing, a fuselage, and an embedded air intake structure as described in any one of claims 1-5, wherein the bottom wall of the air intake body is fixedly connected to the trailing edge of the wing, and the wing is fixedly connected to the fuselage.

7. The aircraft according to claim 6, characterized in that: The air intake body is integrally formed with the wing.

8. The aircraft according to claim 6, characterized in that: The wings are detachably and fixedly connected to the fuselage.

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