Aero-engine nacelle anti-collision structure and machining method thereof

Abstract

According to the anti-collision structure of the aero-engine nacelle and the machining method of the anti-collision structure, the weight of the aero-engine nacelle can be reduced, the strength of the aero-engine nacelle can be improved, the bird impact resistance of the aero-engine nacelle can be improved, and the safety of an aircraft is improved. The aero-engine nacelle anti-collision structure comprises a lip, a first anti-collision part and a second anti-collision part, wherein the lip is arranged at a front end inlet of an aero-engine nacelle; the front bulkhead is arranged on the rear side of the lip opening; and the rear bulkhead is arranged on the rear side of the front bulkhead, and at least one bulkhead of the front bulkhead and the rear bulkhead is provided with a front convex arc-shaped structure protruding towards the lip side.

Description

Technical Field

[0001] The present disclosure relates to an anti-impact structure of an aeroengine nacelle and a processing method thereof, and particularly relates to a structure for preventing damage to an aeroengine nacelle caused by bird strike and a processing method thereof. Background Art

[0002] During the flight of an aircraft, it is inevitable to be struck by a bird. In this field, the event of damage caused by the collision between a bird and a flying artificial aircraft is called "bird strike".

[0003] As one of the components exposed outside the aircraft, the aeroengine nacelle has a probability of being struck by a bird second only to the fan blade of the aeroengine. Therefore, through structural design, the aeroengine nacelle needs to have sufficient anti-bird strike ability.

[0004] In the existing design, in order to meet the requirements of anti-bird strike, the aeroengine nacelle usually adopts a design scheme including a lip, a front bulkhead, and a rear bulkhead. Specifically, the lip is usually integrally formed by thin aluminum sheet metal, and the front bulkhead and the rear bulkhead are formed by splicing titanium alloy plates. According to the design requirements of the aeroengine, since components such as pipelines, sensors, and control systems are generally installed on the rear side of the rear bulkhead, after the aeroengine nacelle is struck by a bird, it is allowed for the lip and the front bulkhead to be penetrated, but it is not allowed for the rear bulkhead to be penetrated or deformed beyond the specified limit. Summary of the Invention

[0005] Problems to be Solved by the Invention

[0006] In the prior art, with the increasing requirement for improving the efficiency of aeroengines, each component is designed to be lighter and lighter, which will bring the problem of reduced component strength. Specifically, in the traditional aeroengine nacelle structure, with the increasing requirement for weight reduction, the reduction of weight will lead to a decrease in structural strength, thus there is a risk of failure of the anti-impact structure under bird strike load.

[0007] In addition, in the design of the aeroengine nacelle, the design of the lip usually needs to meet the requirement of reducing air resistance, and there is very limited room for improvement in its structure, shape, size, etc. Therefore, it is required that the front bulkhead and the rear bulkhead as anti-bird strike components have higher anti-impact ability and can play a greater role in anti-impact.

[0008] However, in the existing design of the front bulkhead and the rear bulkhead, the circumferential segmented processing method is usually adopted, and rivets and other connecting parts are used to splice and form the front bulkhead and the rear bulkhead respectively. In this structure, the strength of the rivets and the rivet holes opened on the bulkhead will become weak links in strength, which will cause the connection part to break under bird strike load and result in the failure of the anti-impact structure.

[0009] It is self-evident that once the anti-impact structure fails and the bird body or bird body fragments penetrate the rear bulkhead after piercing through the front bulkhead, it will pose a threat to the safe operation of the aero-engine and its control system, and further affect the flight safety of the entire aircraft.

[0010] The present disclosure is completed to solve the above problems, and its purpose is to provide an anti-impact structure for an aero-engine nacelle and a processing method thereof, which can take into account the reduction of the weight and the improvement of the strength of the aero-engine nacelle, so as to provide the anti-bird strike ability of the aero-engine nacelle and improve the safety of the aircraft.

[0011] Technical means for solving technical problems

[0012] To solve the above problems, the anti-impact structure of the aero-engine nacelle according to the first invention of the present disclosure includes:

[0013] A lip, which is arranged at the front end entrance of the aero-engine nacelle;

[0014] A front bulkhead, which is arranged at the rear side of the lip; and

[0015] A rear bulkhead, which is arranged at the rear side of the front bulkhead,

[0016] At least one of the front bulkhead and the rear bulkhead has a front convex arc structure protruding towards the lip side.

[0017] In addition, to solve the above problems, the processing method of the anti-impact structure of the aero-engine nacelle according to the second invention of the present disclosure is used to process the anti-impact structure of the aero-engine nacelle.

[0018] The anti-impact structure of the aero-engine nacelle includes:

[0019] A lip, which is arranged at the front end entrance of the aero-engine nacelle;

[0020] A front bulkhead, which is arranged at the rear side of the lip; and

[0021] A rear bulkhead, which is arranged at the rear side of the front bulkhead,

[0022] In the processing method of the anti-impact structure of the aero-engine nacelle,

[0023] At least one of the front bulkhead and the rear bulkhead is processed into a front convex arc structure protruding towards the lip side.

[0024] Advantages of the invention

[0025] According to the anti-impact structure of an aeroengine nacelle and its processing method involved in the present disclosure, it is possible to balance the reduction of the weight and the improvement of the strength of the aeroengine nacelle, thereby providing the anti-bird strike ability of the aeroengine nacelle and improving the safety of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 FIG. is a schematic diagram showing the state of an aeroengine nacelle being struck by a bird.

[0027] Figure 2 FIG. is a schematic diagram showing the anti-impact structure of an aeroengine nacelle according to Embodiment 1 of the present disclosure.

[0028] Figure 3 FIG. is showing Figure 2 a schematic diagram of the structure of the front bulkhead in.

[0029] Figure 4 FIG. is a schematic diagram showing the anti-impact structure of an aeroengine nacelle according to Embodiment 2 of the present disclosure.

[0030] Figure 5 FIG. is showing Figure 4 a schematic diagram of the structure of the front bulkhead in.

[0031] Figure 6 FIG. is showing Figure 5 a schematic diagram of the structure of the filling layer in.

[0032] Figure 7 FIG. is showing Figure 6 a schematic diagram of the deformation process of the negative Poisson's ratio unit cell structure in when being impacted.

[0033] Figure 8 FIG. is a schematic diagram showing the anti-impact structure of an aeroengine nacelle according to Embodiment 3 of the present disclosure.

[0034] Figure 9 FIG. is showing Figure 8 a schematic diagram of the structure of the front bulkhead in.

[0035] Figure 10 FIG. is for Figure 9 illustrating the impact-bearing width of the front bulkhead in when being struck by a bird. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following description provides specific application scenarios and requirements of this specification, aiming to enable those skilled in the art to manufacture and use the content in this specification. For those skilled in the art, various local modifications to the disclosed embodiments are obvious, and the general principles defined here can be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the illustrated embodiments, but has the broadest scope consistent with the claims.

[0037] The terms used herein are for the purpose of describing specific example embodiments only and are not restrictive. For example, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" used herein may also include the plural forms. When used in this specification, the terms "comprising", "including", and / or "containing" mean that the associated features, steps, operations, elements, and / or components exist, but do not exclude the existence of one or more other features, steps, operations, elements, and / or components, or the addition of other features, steps, operations, elements, and / or components in this structure / method.

[0038] In this disclosure, unless otherwise specified, the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc. are based on the orientation or positional relationships shown in the drawings. These terms are mainly used to better describe this disclosure and its embodiments, and are not used to limit that the indicated devices, elements, or components must have a specific orientation, or be constructed and operated in a specific orientation.

[0039] Moreover, in addition to being able to represent orientation or positional relationships, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this disclosure can be understood according to specific circumstances.

[0040] Next, with reference to the drawings, the anti-impact structure of an aeroengine nacelle and its processing method of this disclosure will be described. In the following Figures 1 to 10 the left side in the figure is defined as the front direction of the aeroengine nacelle, and the right side in the figure is defined as the rear direction of the aeroengine nacelle. In addition, each structure in the figure is only for illustration purposes, and its structure, dimensions, etc. are not limited to those shown in the figure.

[0041] Figure 1 is a schematic diagram showing the state of the aeroengine nacelle being hit by a bird.

[0042] As Figure 1As shown, the interior of the nacelle 100 of an aero-engine houses the aero-engine 200, providing an installation platform and necessary protection for the aero-engine 200. The nacelle 100 of an aero-engine includes an engine air intake, a fairing, internal fixing devices, a thrust reverser, and a tail nozzle, etc. Additionally, although not shown in the figure, the nacelle 100 of an aero-engine is connected to the aircraft at the upper rear (upper right in the figure) of the aero-engine 200. The nacelle 100 of an aero-engine is used to ensure that the aero-engine 200 can operate normally under various usage environments and flight states, and convert the thrust of the aero-engine 200 into the power of the aircraft to achieve operations such as propulsion and steering of the aircraft in the air.

[0043] The bird body 300 is one type of foreign object that collides with the aircraft during flight. In the present disclosure, the foreign objects that the anti-impact structure of the nacelle of an aero-engine can resist are not actually limited to the bird body. However, since the probability of the aircraft being struck by a bird during actual flight is greater than that of being struck by other foreign objects, in the present disclosure, the bird body 300 is taken as an example to illustrate the situation when the anti-impact structure of the nacelle of an aero-engine is subjected to a bird strike. Additionally, since the bird body 300 has a certain cutability, both the strengthening wire and the annular protrusion described later can have a certain cutting effect on the bird body 300, and this will be described in detail later.

[0044] Embodiment 1

[0045] Figure 2 It is a schematic diagram showing the anti-impact structure of the nacelle of an aero-engine according to Embodiment 1. Although not limited thereto, in this embodiment, the anti-impact structure of the nacelle of an aero-engine is arranged inside the nacelle 100. Specifically, for example, it is arranged inside the fairing at the entrance of the engine air intake. Additionally, in Figure 2 only the upper half of the cross-section of the nacelle 100 along the central axis ( Figure 1 represented by a dashed line in

[0046] As Figure 2 shown, the anti-impact structure of the nacelle of an aero-engine includes a lip 1, a front bulkhead 2a, and a rear bulkhead 3.

[0047] The lip 1 is integrally formed by stamping a thin aluminum plate and is disposed at the front end entrance of the nacelle 100 of an aeroengine. Specifically, it is disposed at the very front end of the fairing. Regarding the structure, shape, and dimensions of the lip 1, any existing design can be adopted as long as it can meet the requirement of reducing air resistance, and thus, no detailed description will be given in this disclosure. Additionally, in order to minimize weight as much as possible, the lip 1 is integrally formed by stamping a thin aluminum plate. Therefore, its strength is insufficient to resist the impact of the bird body 300, and it can be considered that the bird body 300 will penetrate the lip 1 and reach the front bulkhead 2a described later.

[0048] The front bulkhead 2a is disposed at the rear side of the lip 1 and is used to further block the bird body 300 that penetrates the lip 1. The improvement points of the front bulkhead 2a will be described in detail later. And, in this embodiment, since the rear bulkhead 3 described later needs to undertake a fire prevention function in addition to bird strike resistance, the improvement points are concentrated on the front bulkhead 2a. However, the present invention is not limited thereto. Without considering other factors, the improvement points of the present invention can also be applied to the rear bulkhead 3, or even applied to both the front bulkhead 2a and the rear bulkhead 3 simultaneously, and these solutions are all included within the scope of the technical solutions of the present invention. That is, the improvement points of the present invention can be applied to at least one of the front bulkhead and the rear bulkhead. This point is applicable to each of the following embodiments.

[0049] The rear bulkhead 3 is disposed at the rear side of the front bulkhead 2. When the bird body 300 or its fragments penetrate the front bulkhead 2a, it further blocks the bird body 300 or its fragments. Since important components such as pipelines, sensors, and control systems are usually installed at the rear side of the rear bulkhead 3, in general designs, it is usually required that the rear bulkhead 3 will not be penetrated or have deformation beyond the limit when being impacted.

[0050] The structure of the front bulkhead 2a of this embodiment will be described below.

[0051] Figure 3 is a schematic diagram showing Figure 2 the structure of the front bulkhead 2a in Figure 1 . The front bulkhead 2a is substantially circular in a direction perpendicular to the central axis of the nacelle 100 of the aeroengine ( Figure 3 represented by a dashed line in

[0052] such as Figure 3As shown, in this embodiment, the front bulkhead 2a has a front convex arc structure protruding towards the lip 1 (the left side in the figure). There are no particular limitations on the specific dimensions, protruding degree, etc. of this front convex arc structure, as long as it can provide a certain deformation buffering effect against impacts from the protruding side.

[0053] In this embodiment, since the front bulkhead 2a adopts a front convex arc structure protruding towards the lip 1, compared with the traditional flat structure, it can have a better deformation buffering effect after being hit by a bird. Therefore, even if it is penetrated due to the large impact force of the bird body 300, it can significantly reduce the speed and impact force of the bird body 300, thereby greatly reducing the impact force that the rear bulkhead 3 on the rear side may suffer.

[0054] In addition, as described above, in the prior art, due to process limitations, the original design of the bulkhead of an aeroengine usually adopts circumferential segmented machining and is combined into a complete circle by means of riveting with connectors. However, the strength of the rivets in this structure and the holes drilled in the bulkhead will form weak links, which may cause the bulkhead to fracture and fail at the rivet connection part under bird strike loads.

[0055] In contrast, in this embodiment, the front bulkhead 2a is integrally formed from a first alloy, thus avoiding the emergence of weak links, improving the overall strength of the front bulkhead 2a, and thereby enhancing the reliability of the structure.

[0056] As an example of the first alloy, for example, a lightweight alloy such as TC4 titanium alloy can be used. However, the present invention is not limited thereto, and the density of the first alloy only needs to be less than or equal to the density of the titanium alloy. Thus, it is possible to further reduce the weight of the entire nacelle 100 of the aeroengine while ensuring a certain structural strength.

[0057] In addition, as Figure 3As shown, in the present embodiment, on the surface of the front bulkhead 2a on the side opposite to the lip 1 side, a reinforcing wire 14 made of a second alloy is further formed. The reinforcing wire 14 is arranged along the circumferential direction of the substantially circular front bulkhead 2a. As a specific structural example, the reinforcing wire 14 may include a plurality of circular wires, and the plurality of circular wires may be arranged as a plurality of concentric circles with the central axis of the aeroengine nacelle 100 as the center. Additionally, as another specific structural example, the reinforcing wire 14 may also be a spiral wire that spirally extends gradually from the inner circle to the outer circle of the substantially circular front bulkhead 2a around the central axis of the aeroengine nacelle 100. However, regardless of which structure is adopted, the reinforcing wire 14 has a structure arranged along the circumferential direction of the front bulkhead 2a. The reason is that the main cause of the bird strike failure of the front bulkhead 2a is that it is prone to fracture along the circumferential direction. Therefore, by arranging the reinforcing wire 14 along the circumferential direction of the front bulkhead 2a, the circumferential strength of the front bulkhead 2a can be enhanced, thereby further increasing the impact resistance of the front bulkhead 2a. In addition, by providing the reinforcing wire 14, the bird body 300 that penetrates the front bulkhead 2a can also be cut, thereby further reducing the size of the fragments of the bird body 300. In other words, the bird body 300 that penetrates the front bulkhead 2a is divided into fragments with a smaller speed and lighter weight after passing through the metal mesh formed by the reinforcing wire 14, thereby being able to reduce its impact on the rear bulkhead 3 at the rear side and overall improving the bird strike resistance of the aeroengine nacelle 100.

[0058] As an example of the second alloy, for example, a high-strength alloy steel such as GH4169 with a relatively high tensile strength can be adopted. However, the present invention is not limited thereto, and the strength of the second alloy only needs to be greater than or equal to the strength of the titanium alloy. Thereby, the circumferential strength of the front bulkhead 2a can be ensured, and it can be ensured that the bird body 300 that penetrates the front bulkhead 2a is cut into smaller fragments.

[0059] In addition, although not shown in the figure, a transition layer may be further formed between the reinforcing wire 14 and the front bulkhead 2a, and the transition layer is formed by mixing a first alloy and a second alloy. Since the transition layer has both the components of the first alloy and the second alloy, the strength of the bonding surface between the reinforcing wire 14 and the front bulkhead 2a can be improved.

[0060] Next, a processing method for the impact-resistant structure of the aeroengine nacelle in the present Embodiment 1 will be described.

[0061] Taking Figure 3For example, first, using the metal powder of the first alloy as the raw material, through the 3D printing process, the front bulkhead 2a is integrally formed into a front convex arc structure protruding towards the lip 1 side. Specifically, the so-called "additive manufacturing" method is adopted, that is, using the metal powder of the first alloy as the raw material, through the method of rapid solidification after laser melting, according to the CAD model of the front bulkhead 2a, the front bulkhead 2a is "grown and manufactured" layer by layer by deposition, thus completing a fully dense and high-performance alloy structural part in one step.

[0062] Next, using the metal powder of the second alloy as the raw material, through the 3D printing process, the strengthening wire 14 is grown on the surface of the front bulkhead 2a on the opposite side of the lip 1 side, so that the strengthening wire 14 is arranged along the circumference of the front bulkhead 2a. Specifically, the "additive manufacturing" method is also adopted, using the metal powder of the second alloy as the raw material, through the method of rapid solidification after laser melting, according to the CAD model of the strengthening wire 14, the strengthening wire 14 is "grown and manufactured" layer by layer by deposition on the surface of the front bulkhead 2a on the opposite side of the lip 1 side.

[0063] In addition, during the process of processing and forming the strengthening wire 14, it is also possible to first use a mixture of the metal powder of the first alloy and the metal powder of the second alloy as the raw material, through the 3D printing process, to form a transition layer on the surface of the front bulkhead 2a on the opposite side of the lip 1 side, and then use the metal powder of the second alloy as the raw material, through the 3D printing process, to grow the strengthening wire 14 on the transition layer, thereby improving the bonding surface strength between the two different metals.

[0064] The above has described the anti-impact structure of the aeroengine nacelle and its processing method involved in the first embodiment. According to the above anti-impact structure of the aeroengine nacelle and its processing method, it is possible to take into account both the reduction of the weight and the improvement of the strength of the aeroengine nacelle, thereby providing the anti-bird strike ability of the aeroengine nacelle and improving the safety of the aircraft.

[0065] Embodiment 2

[0066] Figure 4 is a schematic diagram showing the anti-impact structure of the aeroengine nacelle involved in the second embodiment. As Figure 4 shown, the difference between the anti-impact structure of the aeroengine nacelle involved in the second embodiment and Figure 2 that of the first embodiment shown is that the front bulkhead 2b is used instead of the front bulkhead 2a, and other structures are the same as those of the first embodiment. For the structures that are the same as those of the first embodiment, the same reference numerals are marked and the description is omitted.

[0067] Next, centering on the difference between the front bulkhead 2b and the front bulkhead 2a, the anti-impact structure of the aeroengine nacelle involved in the second embodiment will be described.

[0068] Figure 5 It represents Figure 4 a schematic diagram of the structure of the front partition frame 2b in Figure 5 As shown, the front partition frame 2b includes a front wall plate 11, a rear wall plate 12, and a filling layer 13.

[0069] The front wall plate 11 is disposed on the side close to the lip 1, and the rear wall plate 12 is disposed on the side opposite to the side close to the lip 1. The front wall plate 11 and the rear wall plate 12 adopt a thin plate-like structure and are made of a first alloy. In the second embodiment, the thicknesses of the front wall plate 11 and the rear wall plate 12 are the same, for example, both are 0.5 mm. However, the present invention is not limited thereto. The thicknesses of the front wall plate 11 and the rear wall plate 12 may also be different. The front wall plate 11 and the rear wall plate 12 can play a role in shaping the front partition frame 2b. In addition, the front wall plate 11 and the rear wall plate 12 can also play a certain fireproof role.

[0070] The filling layer 13 is sandwiched between the front wall plate 11 and the rear wall plate 12, has a hollow structure, and its thickness is greater than the thickness of the front wall plate 11 and greater than the thickness of the rear wall plate 12. In the second embodiment, the thickness of the filling layer 13 is, for example, 5 mm. By adopting such a "sandwich" structure in which two thin front and rear plates sandwich a relatively thick hollow filling layer 13, the weight is reduced, and the forming quality of the front partition frame 2b is improved. In addition, the spatial advantage in the cavity of the aeroengine nacelle can be fully utilized to increase the overall thickness of the partition, thereby further improving the impact resistance of the front partition frame 2b. At the same time, the hollow filling structure does not increase the weight, so that both the improvement of strength and the reduction of weight can be achieved.

[0071] In addition, in Figure 5 , when the thicknesses of both the front wall plate 11 and the rear wall plate 12 are 0.5 mm and the thickness of the filling layer 13 is 5 mm, it is preferable that the diameter of the reinforcing wire 14 is 1 mm.

[0072] Next, the structural example of the filling layer 13 will be further described.

[0073] Figure 6 It represents Figure 5 the structure of the filling layer 13 in Figure 7 It represents Figure 6 a schematic diagram of the deformation process of the negative Poisson's ratio unit cell structure 21 in

[0074] As Figure 6 , 7 shown, a plurality of negative Poisson's ratio unit cell structures 21 are arranged in the filling layer 13. These negative Poisson's ratio unit cell structures 21 are adjacent to each other in the load-bearing direction (left and right direction in the figure) of the front partition frame 2b and are connected to each other through a partition plate 24 in the direction perpendicular to the load-bearing direction of the front partition frame 2b (up and down direction in the figure).

[0075] Figure 7 The dark lines therein represent the state of the negative Poisson's ratio unit cell structure before being impacted, and the light lines represent the state of the negative Poisson's ratio unit cell structure after being impacted. As Figure 7 shown, when impacted by the impact force G of a bird body, the surrounding negative Poisson's ratio unit cell structures 21 will gather towards the impacted area. Therefore, more materials share the energy of the bird strike impact, and thus can absorb more bird strike impact energy.

[0076] In addition, as Figure 6 shown, in the second embodiment, at the middle position of each negative Poisson's ratio unit cell structure 21, there are two cross plates 22 that cross along the load-bearing direction of the negative Poisson's ratio unit cell structure (the G direction in the figure). By using the cross plates 22, the impact resistance of each negative Poisson's ratio unit cell structure can be further increased. Regarding the number of cross plates 22, it is not limited to two. Without excessively increasing the weight of the filling layer 13, there can also be more than two cross plates that cross along the G direction.

[0077] In addition, as Figure 6 shown, in the second embodiment, in each negative Poisson's ratio unit cell structure 21, at the intersection position of the cross plates 22, there is also an annular structure 23 with the intersection point as the center and the load-bearing direction of the negative Poisson's ratio unit cell structure 21 as the radial direction. As Figure 7 shown, when impacted by the impact force G of a bird body, the annular structure 23 in each negative Poisson's ratio unit cell structure 21 will deform into an ellipse. Therefore, compared with other structures, in the case of using the same weight of materials, the annular structure 23 can absorb more impact energy.

[0078] In addition, in the second embodiment, inside each negative Poisson's ratio unit cell structure 21, a light and soft high-plasticity material can also be filled. As an example of the high-plasticity material, for example, a rubber material can be used. By filling the high-plasticity material, the negative Poisson's ratio unit cell structure can further absorb more impact energy when being impacted. At the same time, the light high-plasticity material will not significantly increase the overall weight of the filling layer 13.

[0079] As described above, by using a structure such as the front bulkhead 2b involved in the second embodiment, the filling layer 13 formed by arranging a plurality of negative Poisson's ratio unit cell structures 21 has a stronger energy absorption effect during the process of being crushed by impact. Therefore, it can further reduce the speed of bird body fragments, and thus can further increase the impact resistance of the anti-impact structure of the aeroengine nacelle without significantly increasing its overall weight.

[0080] Embodiment 3

[0081] Figure 8It is a schematic diagram showing the anti-impact structure of an aero-engine nacelle according to Embodiment 3 of the present disclosure. As Figure 8 shown, the difference between the anti-impact structure of the aero-engine nacelle according to Embodiment 3 and Figure 5 that of Embodiment 2 shown is that the front bulkhead 2c is used instead of the front bulkhead 2b, and other structures are the same as those of Embodiment 2. For the structures that are the same as those of Embodiment 2, the same reference numerals are marked and the description is omitted.

[0082] Next, centering on the difference between the front bulkhead 2c and the front bulkhead 2b, the anti-impact structure of the aero-engine nacelle according to Embodiment 3 will be described.

[0083] Figure 9 It is a schematic diagram showing Figure 8 the structure of the front bulkhead 2c in Figure 9 . As shown, on the surface of the front bulkhead 2c close to the lip 1, specifically, on the surface of the front wall panel 11' that constitutes the front bulkhead 2c, a plurality of annular protrusions 15 are formed. The plurality of annular protrusions 15 protrude from the surface of the front wall panel 11' toward the lip 1, and their tops can be formed into a plurality of concentric circles centered on the central axis of the aero-engine nacelle 100. And, as Figure 9 shown, the cross-section of the plurality of annular protrusions 15 along the radial direction of the aero-engine nacelle 100 is formed into a serrated shape.

[0084] Figure 10 It is a schematic diagram for explaining Figure 9 the impact-bearing width of the front bulkhead in the case of a bird strike. Among them, the left part shows the state of the front bulkhead with a flat front wall panel 11 when being struck by a bird, and the right part shows the state of the front bulkhead with the front wall panel 11' with serrated annular protrusions 15 of the present embodiment when being struck by a bird. Here, for the convenience of explanation, the bird body 300 is equivalent to a cylinder.

[0085] As Figure 10 shown, the bird body 300 impacts the front wall panel with an initial velocity v. When using a flat front wall panel 11, the impact-bearing width when bearing the impact of the bird body 300 is a, that is, the bird body impact area is small, the force is relatively concentrated, and less material absorbs the bird body impact energy through deformation or failure. On the other hand, when using the front wall panel 11' with serrated annular protrusions 15 of the present embodiment, since the annular protrusions 15 can cut the bird body 300 in the radial direction and make the bird body fragments spread to both sides, the impact-bearing width when bearing the impact of the bird body 300 is increased to b (b > a), thereby effectively increasing the bird body impact area and enabling more material to absorb more bird body impact energy through deformation or failure.

[0086] In addition, in practical applications, sometimes the size of the bird body 300 may be relatively small. Therefore, in order to cope with the situation where the bird body 300 is relatively small, it is preferable that the serrations of the annular protrusion 15 with a serrated radial cross-section have acute-angled serrations. The reason is that even when the bird body 300 is relatively small, the acute-angled serrations can still cut the bird body 300 into multiple smaller pieces. Thus, the impact-bearing width can be further increased, thereby absorbing more bird impact energy.

[0087] As described above, by using a structure such as the front bulkhead 2c involved in the third embodiment, the bird body 300 is first cut by the serrated annular protrusion 15 formed on the surface of the front wall panel 11' and becomes scattered small pieces. Thus, the contact area between the bird body and the front bulkhead 2c can be increased, further enhancing the impact resistance of the anti-impact structure of the aeroengine nacelle, and without significantly increasing its overall weight.

[0088] The above describes the anti-impact structure of the aeroengine nacelle and its processing method according to the present invention. It should be considered that all aspects of the disclosed embodiments are merely illustrative and not restrictive. The scope of the present disclosure is represented by the claims, rather than by the above embodiments. The scope of the present disclosure also includes all modifications and variations within the meaning and scope equivalent to the claims.

[0089] Industrial Applicability

[0090] As described above, according to the anti-impact structure of the aeroengine nacelle and its processing method of the present disclosure, it helps to improve the anti-impact ability of the aeroengine nacelle, and is particularly useful for the bird strike protection of the engine nacelle during the flight of the aircraft.

[0091] Reference Signs Explanation

[0092] 1 Lip

[0093] 2a, 2b, 2c Front Bulkhead

[0094] 3 Rear Bulkhead

[0095] 11, 11' Front Wall Panel

[0096] 12 Rear Wall Panel

[0097] 13 Filling Layer

[0098] 14 Reinforcing Wire

[0099] 15 Annular Protrusion

[0100] 16 Connection Structure

[0101] 21 Negative Poisson's Ratio Unit Cell Structure

[0102] 22 Cross plate

[0103] 23 Annular structure

[0104] 24 Partition board

[0105] 25 Arc-shaped plate

[0106] 100 Aircraft engine nacelle

[0107] 200 Aircraft engine

[0108] 300 Bird body.

Claims

1. An impact-resistant structure for an aeroengine nacelle, characterized in that, it includes: a lip, which is arranged at the front end entrance of the aeroengine nacelle; a front bulkhead, which is arranged at the rear side of the lip; and a rear bulkhead, which is arranged at the rear side of the front bulkhead, at least one of the front bulkhead and the rear bulkhead has a front convex arc structure protruding towards the lip side.

2. The impact-resistant structure for an aeroengine nacelle according to claim 1, characterized in that, the bulkhead with the front convex arc structure among the front bulkhead and the rear bulkhead is integrally formed from a first alloy.

3. The impact-resistant structure for an aeroengine nacelle according to claim 2, characterized in that, the density of the first alloy is less than or equal to the density of titanium alloy.

4. The impact-resistant structure for an aeroengine nacelle according to claim 2, characterized in that, on the surface of the bulkhead with the front convex arc structure on the side opposite to the lip side, a reinforcing wire made of a second alloy is formed, and the reinforcing wire is arranged along the circumferential direction of the bulkhead with the front convex arc structure.

5. The impact-resistant structure for an aeroengine nacelle according to claim 4, characterized in that, the strength of the second alloy is greater than or equal to the strength of titanium alloy.

6. The impact-resistant structure for an aeroengine nacelle according to claim 4, characterized in that, a transition layer is formed between the reinforcing wire and the surface of the bulkhead with the front convex arc structure on the side opposite to the lip side, and the transition layer is mixed by the first alloy and the second alloy.

7. The impact-resistant structure for an aeroengine nacelle according to any one of claims 1 to 6, characterized in that, the bulkhead with the front convex arc structure among the front bulkhead and the rear bulkhead includes: a front wall panel, which is arranged on the side close to the lip; a rear wall panel, which is arranged on the side opposite to the side close to the lip; and a filling layer, which is sandwiched between the front wall panel and the rear wall panel, the filling layer has a hollow structure, and its thickness is greater than the thickness of the front wall panel and greater than the thickness of the rear wall panel.

8. The impact-resistant structure for an aeroengine nacelle according to claim 7, characterized in that, a plurality of negative Poisson's ratio unit cell structures are arranged in the filling layer.

9. The impact-resistant structure for an aeroengine nacelle according to claim 8, characterized in that, at least two cross plates intersecting along the load-bearing direction of the negative Poisson's ratio unit cell structure are provided at the middle position of the negative Poisson's ratio unit cell structure.

10. The impact-resistant structure for an aeroengine nacelle according to claim 9, characterized in that, at the intersection point of the cross plates, a circular ring structure with the intersection point as the center and the load-bearing direction of the negative Poisson's ratio unit cell structure as the radial direction is provided.

11. The impact-resistant structure for an aeroengine nacelle according to claim 8, characterized in that, a high-plasticity material is filled inside the negative Poisson's ratio unit cell structure.

12. The impact-resistant structure for an aeroengine nacelle according to any one of claims 1 to 6, characterized in that, On the surface of the septum frame with the front convex arc structure in the front septum frame and the rear septum frame, on the side close to the lip, a plurality of annular protrusions are formed, and the cross-section of the plurality of annular protrusions along the radial direction is formed into a zigzag shape.

13. The anti-impact structure of an aeroengine nacelle according to claim 12, wherein, the zigzag shape has sawteeth with acute angles.

14. A processing method for an anti-impact structure of an aeroengine nacelle, used for processing the anti-impact structure of an aeroengine nacelle, the anti-impact structure of the aeroengine nacelle comprises: a lip, which is arranged at the front end entrance of the aeroengine nacelle; a front septum frame, which is arranged at the rear side of the lip; and a rear septum frame, which is arranged at the rear side of the front septum frame, the characteristics of the processing method for the anti-impact structure of the aeroengine nacelle are that, at least one of the front septum frame and the rear septum frame is processed into a front convex arc structure protruding towards the lip side.

15. The processing method for the anti-impact structure of an aeroengine nacelle according to claim 14, wherein, using the metal powder of the first alloy as raw material, through the 3D printing process, the septum frame with the front convex arc structure in the front septum frame and the rear septum frame is integrally formed.

16. The processing method for the anti-impact structure of an aeroengine nacelle according to claim 15, wherein, the density of the first alloy is less than or equal to the density of the titanium alloy.

17. The processing method for the anti-impact structure of an aeroengine nacelle according to claim 15, wherein, using the metal powder of the second alloy as raw material, through the 3D printing process, on the surface of the septum frame with the front convex arc structure, on the side opposite to the lip side, strengthening metal wires are grown, and the strengthening metal wires are arranged along the circumferential direction of the septum frame with the front convex arc structure.

18. The processing method for the anti-impact structure of an aeroengine nacelle according to claim 17, wherein, the strength of the second alloy is greater than or equal to the strength of the titanium alloy.

19. The processing method for the anti-impact structure of an aeroengine nacelle according to claim 17, wherein, using the mixture of the metal powder of the first alloy and the metal powder of the second alloy as raw material, through the 3D printing process, a transition layer is formed between the strengthening metal wires and the surface of the septum frame with the front convex arc structure, on the side opposite to the lip side.

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