A low-scattering carrier for RCS testing

Abstract

The present application relates to a kind of low scattering carriers for RCS test, including carrier body, carrier body includes first surface and second surface, first surface and second surface are connected to form hollow cavity, hollow cavity is used to accommodate cylindrical target component;One end of hollow cavity is tip, the other end is open end, open end is circular, cylindrical target component is installed in hollow cavity through open end;Horizontal plane is formed at the junction of first surface and second surface, the height of first surface beyond horizontal plane is less than the height of second surface beyond horizontal plane, the radius of curvature of first surface gradually increases from tip to open end direction, the radius of curvature of second surface increases first and then decreases from tip to open end direction.The low scattering carrier in the present application can simulate the installation state of cylindrical target component, realize the accurate evaluation of the RCS of cylindrical target component.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of target far-field electromagnetic scattering characteristic test, and particularly relates to a low-scattering carrier for RCS test. BACKGROUND

[0002] With the rapid development of radar detection technology, it is necessary to design the radar stealth layout of an aircraft. Therefore, after the overall stealth design of the aircraft is completed, the stealth performance of the target component needs to be evaluated.

[0003] However, when the cylindrical target component is separated from the body structure of the aircraft, an interference source that did not exist before appears, and the edges, surfaces and cavities of the cylindrical target component that did not exist before are exposed to radar wave irradiation. If no measures are taken, the accuracy of the evaluation result of the cylindrical target component will be affected.

[0004] In the related art, the low-scattering carrier cannot be applied to the RCS test of the cylindrical structure aircraft component. Therefore, there is an urgent need to provide a low-scattering carrier for the RCS test of the cylindrical structure. SUMMARY

[0005] The low-scattering carrier for RCS test provided by the embodiments of the present application can simulate the installed state of the cylindrical target component, and realize accurate evaluation of the RCS of the cylindrical target component.

[0006] The low-scattering carrier for RCS test provided by the embodiments of the present application comprises:

[0007] The carrier body comprises a first surface and a second surface that protrude outward, and the first surface and the second surface are connected to form a hollow cavity for accommodating the cylindrical target component;

[0008] One end of the hollow cavity is a pointed end, and the other end is an open end, the open end is circular, and the cylindrical target component is installed in the hollow cavity through the open end;

[0009] The first surface and the second surface form a horizontal plane at the junction, the height of the first surface beyond the horizontal plane is less than the height of the second surface beyond the horizontal plane, the radius of curvature of the first surface gradually increases from the pointed end to the open end, and the radius of curvature of the second surface first increases and then decreases from the pointed end to the open end.

[0010] In a possible design, the junctions of the first surface and the second surface on both sides form a first side edge and a second side edge that protrude outward, and the radius of curvature of the first side edge and the second side edge both first increases and then decreases from the pointed end to the open end.

[0011] In a possible design, the bending directions of the first side edge and the second side edge are opposite, and at the tip end, a tangent line of an end point of the first side edge intersects with a tangent line of an end point of the second side edge to form a front end included angle, and the front end included angle is an acute angle.

[0012] In a possible design, the front end included angle is 40°-70°.

[0013] In a possible design, the second surface comprises a smooth curved surface and a plane, the smooth curved surface and the plane are continuously connected in curvature, and the plane is provided with an opening hole for penetrating a supporting part supporting the cylindrical target part.

[0014] In a possible design, a cover body is further included, and the cover body is used for covering the opening end.

[0015] In a possible design, the cover body is a conical structure, the conical structure comprises a top end and a bottom end, the top end is away from the opening end, and the bottom end is connected to the opening end of the carrier body, so that the low-scattering carrier is in a spindle structure.

[0016] In a possible design, the cover body and the carrier body are continuously connected in curvature at the connection position.

[0017] In a possible design, a horizontal projection of the cover body comprises a first arc line and a second arc line, the bending directions of the first arc line and the second arc line are opposite, at the top end, a tangent line of an end point of the first arc line intersects with a tangent line of an end point of the second arc line to form a top end included angle, and the top end included angle is 80°-90°.

[0018] In a possible design, the cover body is projected onto a vertical plane to form a vertical projection, the vertical projection comprises a first curve and a second curve, a radius of curvature of the first curve gradually decreases from the bottom end to the top end of the cover body, and a radius of curvature of the second curve gradually increases and then decreases twice from the bottom end to the top end of the cover body.

[0019] In a possible design, the roughness of the surface of the low-scattering carrier is less than 1.6.

[0020] Compared with the prior art, the present application has at least the following beneficial effects:

[0021] In the application, the carrier body can effectively shield the additional electromagnetic wave scattering caused by the original edge, concave cavity and other accessory structures of the cylindrical target component after the cylindrical target component separates from the aircraft body, has a lower RCS value in the main detection angle domain, can better simulate the state of the cylindrical target component in the actual installation, and thus ensures the accuracy of the RCS evaluation of the cylindrical target component; meanwhile, the curvature transition form of the first surface and the second surface of the carrier body in the application makes the carrier body in the application have a better surface current guiding effect, thus reducing the contribution of the traveling wave scattering and the edge scattering, effectively avoiding the fluctuation of the carrier body in the low scattering angle domain, and making the carrier body in the application have a lower RCS value in a wide angle domain in the high frequency band, and thus further ensuring the accurate evaluation of the RCS of the cylindrical target component. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0023] Figure 1 is a front view structural schematic diagram of a low-scattering carrier for RCS test provided by an embodiment of the present application;

[0024] Figure 2 is a top view structural schematic diagram of a low-scattering carrier for RCS test provided by an embodiment of the present application;

[0025] Figure 3 is a front view structural schematic diagram of a low-scattering carrier for RCS test provided by another embodiment of the present application;

[0026] Figure 4 is a bottom view structural schematic diagram of a low-scattering carrier for RCS test provided by another embodiment of the present application;

[0027] Figure 5 is a front view structural schematic diagram of a low-scattering carrier for RCS test provided by another embodiment of the present application;

[0028] Figure 6 is a front view structural diagram of a low-scattering carrier for RCS test provided by still another embodiment of the present application;

[0029] Figure 7 is a horizontal projection diagram of a cover body of a low-scattering carrier for RCS test provided by an embodiment of the present application;

[0030] Figure 8is a top structure diagram of a low-scattering carrier for RCS test provided by another embodiment of the present application;

[0031] Figure 9 is a vertical projection diagram of a cover of a low-scattering carrier for RCS test provided by an embodiment of the present application.

[0032] Reference signs:

[0033] 1-carrier body; 11-first surface; 12-second surface; 111-tip; 112-open end; 121-smooth curved surface; 122-flat surface; 221-hole; 15-horizontal plane; 16-first side edge; 17-second side edge; 131-front end angle; 2-cover; 21-top end; 22-bottom end; 23-first arc; 24-second arc; 25-top end angle; 26-first curve; 27-second curve; 3-supporting structure. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] Generally, the scattering superposition of each component determines the overall stealth performance of the target after the overall stealth design of the aircraft is completed, so it is necessary to separately evaluate the RCS of each component of the aircraft. The cylindrical component is one of the components of the aircraft. However, when the cylindrical target component is separated from the overall aircraft, the original edge structure, surface cavity and other accessory structures are exposed to radar wave irradiation, which will seriously affect the accuracy of the RCS test and evaluation of the cylindrical target component. Based on this, the embodiments of the present application provide a low-scattering carrier for RCS test, as shown in the drawings, which comprises a carrier body 1, the carrier body 1 comprises an outwardly protruding first surface 11 and a second surface 12, the first surface 11 and the second surface 12 are connected to form a hollow cavity, and the hollow cavity is used for accommodating a cylindrical target component. Figure 1

[0036] One end of the hollow cavity is a tip 13, and the other end is an open end 14, the open end 14 is circular, and the cylindrical target component is installed in the hollow cavity through the open end 14;

[0037] ​The first surface 11 and the second surface 12 form a horizontal plane 15 at the junction, the height of the first surface 11 beyond the horizontal plane 15 is less than that of the second surface 12, the radius of curvature of the first surface 11 gradually increases from the tip 13 to the open end 14, and the radius of curvature of the second surface 12 first increases and then decreases from the tip 13 to the open end 14.

[0038] In the present application, in order to avoid the interference of the edge structure and the attached structure of the cylindrical target component with the accuracy of the RCS evaluation, the carrier body 1 is arranged as a hollow cavity formed by the connection of the first surface 11 and the second surface 12, and when the RCS test is performed, the end of the cylindrical target component that causes interference is placed in the hollow cavity through the open end 14, and the end of the cylindrical structure exposed beyond the open end is exposed to the radar wave (not shown in the figure), the carrier body 1 can wrap the interference structure of the cylindrical target component and shield the embedded structure, thereby ensuring the accuracy of the RCS test structure of the cylindrical target component and avoiding the interference of the scattering of the edge structure, embedded structure and the like with the test results of the cylindrical target component; at the same time, the curvature transition form of the first surface 11 and the second surface 12 of the carrier body 1 is as shown in Figure 1 , the radius of curvature of the first surface 11 gradually increases from the tip 13 to the open end 14, and the radius of curvature of the second surface 12 first slowly increases from the tip 13 to the open end 14, and then gradually decreases after reaching the highest point, so that not only a larger accommodation space can be provided for the cylindrical target component, but also the carrier body 1 has a better surface current guiding effect, which can greatly reduce the contribution of the traveling wave scattering when vertically polarized, thereby effectively suppressing the traveling wave scattering in the threat angle domain and effectively avoiding the fluctuation of the carrier body in the low scattering angle domain, and further ensuring the accuracy of the cylindrical target component when performing the RCS test evaluation.

[0039] As shown in Figure 2 , in some embodiments, the junctions on both sides of the first surface 11 and the second surface 11 form outwardly protruding first side edges 16 and second side edges 17, and the radius of curvature of the first side edges 16 and the second side edges 17 both first increases and then decreases from the tip 13 to the open end 14.

[0040] In some embodiments, the bending directions of the first side edges 16 and the second side edges 17 are opposite, and at the tip 13, the tangent line of the endpoint of the first side edge 16 intersects with the tangent line of the endpoint of the second side edge 17 to form a front end included angle 131, and the front end included angle 131 is an acute angle.

[0041] In some embodiments, the degree of the front end included angle 131 is 40°-70°.

[0042] As shown in Figures 3-4As shown, in some embodiments, the second surface 12 includes a smooth curved surface 121 and a plane 122, which are continuously transitioned by curvature. The plane 122 is provided with an opening 221 for inserting a support member 3 that supports the cylindrical target member.

[0043] This invention features a plane 122 at the bottom of the carrier body, adapted to an experimental platform. This plane 122 allows for stable placement of the low-scattering carrier in both experimental and storage environments. The plane 122 has an opening 221 for the support component 3 that supports the cylindrical target structure, thus ensuring the stability of the cylindrical target component during measurement and evaluation. In practice, the size of the opening can be determined based on the dimensions of the support structure. It should also be noted that... Figure 5 As shown, in this invention, the plane 122 is preferably set at the point of maximum radius of curvature corresponding to the second surface 11 of the carrier body 1. This not only ensures that the carrier body has a low RCS, but also better adapts to the support component 3, thereby achieving stable support for the cylindrical target component.

[0044] It should be noted that when conducting RCS testing on cylindrical target components, the connection between the open end of the carrier body and the cylindrical target component is conformally flush (i.e., flush), and the two are tightly connected. During testing, after installing the cylindrical target component and the carrier, only the connection seams and backfill holes of the lifting points on the carrier body need to be treated.

[0045] like Figure 6 As shown, in some embodiments, a cover 2 is also included, which is used to cover the opening end 14.

[0046] like Figure 6 As shown, in some embodiments, the cover 2 is a cone-shaped structure, including a top end 21 and a bottom end 22. The top end 21 is away from the opening end 14, and the bottom end 22 is connected to the opening end 14 of the carrier body 1, so that the low scattering carrier has a spindle-shaped structure; the curvature at the connection between the cover 2 and the carrier body 1 is continuously transitioned.

[0047] In this invention, before evaluating the RCS of the cylindrical target component, it is necessary to first evaluate the overall RCS value of the low-scattering carrier. In this case, the low-scattering carrier consists of a carrier body 1 and a cover 2. The cover 2 has a conical structure, and the diameter of the bottom end 22 of the conical structure is the same as the diameter of the opening end 12 of the hollow cavity. This allows the bottom end 22 of the conical structure to be tightly connected to the opening end 14 of the hollow cavity without any step difference. Simultaneously, a connecting flange is provided at the opening end 14 of the carrier body 1, allowing the carrier body 1 and the cover 2 to be fixed together via the connecting flange. The gap at the connection point can be treated by pasting aluminum foil, thereby eliminating the influence of surface mounting gaps on the test results of the low-scattering carrier. Figure 6 As shown, the bottom end 22 of the cover 2 is connected to the opening end 14 of the carrier body 1, so that the low-scattering carrier in the present invention has a spindle-shaped structure with both ends pointed, and the low-scattering carrier has a symmetrical structure along the line connecting the tip 13 of the carrier body 1 to the top end 21 of the cover 2.

[0048] like Figure 7 As shown, in some embodiments, the horizontal projection of the cover 2 includes a first arc 23 and a second arc 24, the first arc 23 and the second arc 24 have opposite curvature directions, and at the top 21, the tangent of the endpoint of the first arc 23 intersects the tangent of the endpoint of the second arc 24 to form a top angle 25, the degree of the top angle 25 being 80° to 90°.

[0049] According to electromagnetic wave scattering theory, the angles between the front and rear ends of the carrier determine the low-scattering angular domain of the low-scattering carrier. For specific RCS (Radio Frequency Cross-Section) requirements, choosing appropriate front and rear angles is particularly important. When a horizontally polarized wave is incident, the surface of the carrier body is parallel to the electric field and does not generate traveling wave currents. However, the carrier edges form a certain angle with the electric field, causing traveling wave currents to be generated at the edges of the carrier body. These currents are reflected when encountering abrupt changes at the edges, forming edge traveling wave scattering, such as... Figure 8 As shown, in this invention, the front angle of the low-scattering carrier (i.e., the front angle 131 in the figure) is smaller than the rear angle (i.e., the top angle 25 in the figure), and the front angle and the rear angle are set within a specific range. Within the above angle range, the carrier has lower scattering characteristics relative to the cylindrical target component being tested, thus having less impact on the RCS measurement of the target component, which is beneficial to ensuring the accuracy of the RCS test of the cylindrical target component.

[0050] It should also be noted that the cover in this invention is installed during the overall evaluation of the low-scattering carrier before the RCS test of the cylindrical target component. The cover needs to be removed when the RCS test of the cylindrical target component is performed.

[0051] likeFigure 9 As shown, in some embodiments, the cover 2 is projected to a plane perpendicular to the horizontal plane to form a vertical projection, the vertical projection comprising a first curve 26 and a second curve 27, the radius of curvature of the first curve 26 gradually decreases from the bottom end 22 to the top end 21 of the cover 2, and the radius of curvature of the second curve 27 first increases and then decreases twice from the bottom end 22 to the top end 21 of the cover 2.

[0052] In the present application, the vertical projection of the cover specifically refers to Figure 6 The vertical projection of the cover in the present application is formed by projecting the cover to a plane perpendicular to the horizontal plane according to the placement mode of the cover, that is, the vertical projection in the present application, which comprises a first curve 26 and a second curve 27, the interface between the plane formed by the first curve 26 and the second curve 27 and the first surface 11 and the second surface 12 of the carrier body has a continuous transition in curvature without obvious step difference, and when the low-scattering carrier is used for overall RCS evaluation, the gap between the carrier body and the cover is pasted with aluminum foil, which ensures that there is no surface discontinuity echo reflection and strong specular reflection source at the connection; at the same time, in the present application, the curvature transition form of the cover surface is further designed to make the shape of the low-scattering carrier in the present application a spindle structure, which is similar to the shape of a bird and can avoid the contribution of the row wave scattering and creeping wave and other secondary scattering sources generated when the low-scattering carrier is vertically polarized to the RCS of the carrier.

[0053] In some embodiments, the roughness of the surface of the low-scattering carrier is less than 1.6.

[0054] The roughness of the carrier is less than 1.6, which is more conducive to reducing the scattering of electromagnetic waves propagating on the carrier; at the same time, in the present application, the low-scattering carrier can be made of aluminum material, which is conducive to reducing the scattering of electromagnetic waves propagating from the target component to the surface of the low-scattering carrier, and the electromagnetic wave propagates on the aluminum material with less scattering, which is also conducive to reducing the weight of the low-scattering carrier.

[0055] In actual application, the length of the low-scattering carrier is 4 to 7 meters, the width is 2 to 3 meters, and the height is 1.5 to 2 meters. The length specifically refers to Figure 6 the length of the line between the pointed end 13 and the top end 21, the height specifically refers to Figure 6 the maximum vertical distance of the line between the highest point of the first surface 11 and the highest point of the second surface 12, and the width specifically refers to Figure 8 the maximum vertical distance of the line between the first side edge 16 and the second side edge 17.

[0056] The low-scattering carrier designed in this invention, due to its relatively continuous surface curvature and the absence of cavities or other structures, lacks strong scattering sources such as specular reflection and multiple reflections, thus exhibiting good surface current guiding properties. During RCS verification of the low-scattering carrier itself, its low-scattering characteristics relative to the tested cylindrical target component minimize its impact on the RCS evaluation. In actual testing, the RCS of the low-scattering carrier is significantly superior to that of the cylindrical target component. Furthermore, the size and weight of the aforementioned low-scattering carrier are controlled within the testing capabilities of the experimental platform.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-scattering carrier for RCS testing, characterized in that, The carrier body comprises a first surface and a second surface which are connected to form a hollow cavity for accommodating a cylindrical target component; One end of the hollow cavity is a pointed end and the other end is an open end, the open end is circular, and the cylindrical target component is installed in the hollow cavity through the open end; The first surface and the second surface form a horizontal plane at the junction, the height of the first surface above the horizontal plane is less than the height of the second surface above the horizontal plane, the radius of curvature of the first surface gradually increases from the pointed end to the open end, and the radius of curvature of the second surface first increases and then decreases from the pointed end to the open end; the junction of the first surface and the second surface on both sides forms a first side edge and a second side edge which are outwardly convex, the radius of curvature of the first side edge and the second side edge both first increases and then decreases from the pointed end to the open end; the bending directions of the first side edge and the second side edge are opposite, at the pointed end, the tangent lines of the endpoints of the first side edge and the second side edge intersect to form a front end included angle, and the front end included angle is an acute angle; The second surface comprises a smooth curved surface and a plane, the smooth curved surface and the plane are continuously transitioned in curvature, and the plane is provided with an opening for penetrating a supporting component for supporting the cylindrical target component; Further comprising a covering body for covering the open end; The covering body is a conical structure, the conical structure comprises a top end and a bottom end, the top end is away from the open end, and the bottom end is butted at the open end of the carrier body to make the low-scattering carrier present a spindle structure; the connection between the covering body and the carrier body is continuously transitioned in curvature; The horizontal projection of the covering body comprises a first arc line and a second arc line, the bending directions of the first arc line and the second arc line are opposite, at the top end, the tangent lines of the endpoints of the first arc line and the second arc line intersect to form a top end included angle, and the degree of the top end included angle is 80°-90°; The covering body projects onto a plane perpendicular to the horizontal plane to form a vertical projection, the vertical projection comprises a first curve and a second curve, the radius of curvature of the first curve gradually decreases from the bottom end to the top end of the covering body, and the radius of curvature of the second curve first increases and then decreases from the bottom end to the top end of the covering body.

2. The low-scattering carrier of claim 1, wherein, The degree of the front end included angle is 40°-70°.

3. The low-scattering carrier of any one of claims 1 to 2, wherein, The roughness of the surface of the low-scattering carrier is less than 1.6.

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