A high-density flow front fuselage shell and front fuselage for an aircraft with abdominal air intake

Abstract

The present invention relates to a high-density flow front fuselage shell and a front fuselage for an abdominal air intake aircraft. The high-density flow front fuselage shell includes a front fuselage back structure and a front fuselage belly structure. Along the longitudinal direction of the high-density flow front fuselage shell, the front ends of the front fuselage back structure and the front fuselage belly structure are connected to each other. Along the transverse direction of the high-density flow front fuselage shell, the left and right ends of the front fuselage back structure are respectively connected to the left and right ends of the front fuselage belly structure. Along the direction from the front end to the rear end of the front fuselage back structure, the back outer surface of the front fuselage back structure is an outwardly convex curved surface that bulges along the normal direction. Along the direction from the front end to the rear end of the front fuselage belly structure, the belly outer surface of the front fuselage belly structure includes a pre-compression surface and a density flow enhancement surface that are connected in sequence. A transition structure is provided at the position where the pre-compression surface and the density flow enhancement surface are connected. The present invention has high compression efficiency for the oncoming air flow, small flow loss, and low aerodynamic drag.

Description

Technical Field

[0001] The present invention relates to the field of aerospace, and particularly to a high-density flow front fuselage shell and a front fuselage for an aircraft with ventral air intake. Background Art

[0002] For practical high-speed aircraft, it is necessary to comprehensively consider various performance indicators such as internal loading space, external geometric envelope, integrated aerodynamic characteristics, and air capture efficiency. Among them, the ventral air intake layout scheme is the most likely to meet the above requirements simultaneously.

[0003] The front fuselage is the key component of an aircraft with ventral air intake. In engineering practice, on the one hand, the front fuselage is required to have excellent aerodynamic performance, such as high lift and low drag; on the other hand, it is also required to have good loading capacity and structural performance, such as large space volume, easy processing, and easy heat protection. For high-speed aircraft, it is often necessary to integrate the design of the front fuselage and the air intake, which poses higher requirements for the front fuselage. In addition to meeting the basic aerodynamic performance requirements, loading and structural performance requirements, it should also ensure that the air intake can capture enough high-quality oncoming flow. Furthermore, due to the startup and non-startup problems that often exist in the air intakes of high-speed aircraft, when the air intake does not start, it will seriously threaten flight safety, and the design of the front fuselage is also directly related to the startup ability of the air intake.

[0004] Currently, the research and engineering practice on the design of the front fuselage of high-speed aircraft with ventral air intake are relatively common, as follows:

[0005] The X-43A and X-51A hypersonic aircraft in the United States are representative high-speed aircraft with abdominal intakes. Both of them adopt an integrated scheme of a lifting-body forebody and a two-dimensional intake (Reference: Wang Zhenguo, Liang Jianhan, Fan Xiaoqiang, et al. Integrated scheme of air-breathing hypersonic aircraft: Review and prospect [J]. Acta Aerodynamica Sinica, 2023, 41(8): 13-25.). Among them, the forebody of the X-43A provides three-stage wedge compression (Reference: Meng Yupeng, Yang Hui, Man Yanjin. Development of integrated design technology for hypersonic inlet aircraft [J]. Gas Physics, 2021, 6(4): 66-83.), while the compression of the gas by the forebody of the X-51A is achieved by two-stage planar compression. There is also an overflow window between the intake and the forebody (Reference: HANK J. The X-51A scramjet engine flight demonstration program; BORG M P. Effect of freestream noise on roughness-induced transition for the X-51A forebody). In addition, the differences between the X-43A and X-51A are also reflected in the leading-edge profile: the leading edge of the X-43A is a straight line, and the leading edge of the X-51A is a quasi-elliptical curve. Due to the single compression direction, the mass flux at the inlet of the intake of the X-43A and X-51A is not high.

[0006] In addition, the HSSW aircraft represents another type of high-speed aircraft with abdominal intakes. In order to increase the loading space, this type of aircraft generally adopts an axisymmetric or quasi-axisymmetric convex forebody, which results in a low mass flux at the inlet of the intake. To make up for this defect, a three-dimensional internal turning intake is arranged on the abdominal surface of the HSSW (Reference: Wu Hui, Niu Wen. The United States actively develops hypersonic weapons [J]. Aerodynamic Missile Journal, 2014(8): 4.). This intake effectively increases the mass flux through three-dimensional compression in multiple directions, but there are problems such as the heavy structure of the intake and the difficulty of heat protection for the sharp leading edge. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a high-mass-flux forebody shell and forebody for an abdominal-intake aircraft.

[0008] To achieve the above-mentioned invention purpose, the present invention provides a high-mass-flux forebody shell for an abdominal-intake aircraft, including: a forebody back structure and a forebody abdominal structure;

[0009] Along the longitudinal direction of the high-mass-flux forebody shell, the front ends of the forebody back structure and the forebody abdominal structure are connected to each other;

[0010] Along the transverse direction of the high-density flow front fuselage shell, the left and right ends of the front fuselage back structure are respectively connected to the left and right ends of the front fuselage belly structure;

[0011] Along the direction from the front end to the rear end of the front fuselage back structure, the back outer surface of the front fuselage back structure is a convex curved surface that bulges along the normal direction;

[0012] Along the direction from the front end to the rear end of the front fuselage belly structure, the belly outer surface of the front fuselage belly structure includes: a pre-compression surface and a dense flow enhancement surface that are connected in sequence;

[0013] A transition structure is provided at the position where the pre-compression surface and the dense flow enhancement surface are connected.

[0014] According to one aspect of the present invention, along the longitudinal direction of the high-density flow front fuselage shell, the back outer surface and the belly outer surface are respectively axisymmetric surfaces.

[0015] According to one aspect of the present invention, the dense flow enhancement surface includes: a forward compression surface part, a lateral compression surface part, and a fairing surface part;

[0016] Along the transverse direction of the high-density flow front fuselage shell, the lateral compression surface part is respectively provided at the left and right ends of the forward compression surface part, and the fairing surface part is provided at one end of the lateral compression surface part away from the forward compression surface part;

[0017] Along the direction from the front end to the rear end of the front fuselage belly structure, at least part of the position where the lateral compression surface part is connected to the fairing surface part protrudes along the normal direction away from the front fuselage back structure.

[0018] According to one aspect of the present invention, along the direction from the front end to the rear end of the front fuselage belly structure, the protruding height of the position where the lateral compression surface part is connected to the fairing surface part along the normal direction away from the front fuselage back structure is variable; and, the front width of the lateral compression surface part is greater than its rear width, and the front width of the fairing surface part is less than its rear width.

[0019] According to one aspect of the present invention, along the transverse direction of the high-density flow front fuselage shell, the lateral compression surface part is provided with a recessed structure and a protruding structure that are connected to each other; wherein, the recessed structure is adjacent to the forward compression surface part; the protruding structure is adjacent to the fairing surface part.

[0020] According to one aspect of the present invention, the back outer surface is generated by using one of the CST modeling method, PARSEC method, B-spline curve method, Hicks-Henne basis function method, FFD free deformation method, and streamline tracing method;

[0021] The abdominal external profile is generated by one of the CST modeling method, PARSEC method, B-spline curve method, Hicks-Henne basis function method, FFD free deformation method, and streamline tracking method;

[0022] According to one aspect of the present invention, the pre-compression profile is one or a combination of a plane, a convex surface, and a concave surface;

[0023] The projection of the pre-compression profile is one of a semi-elliptical shape, a quasi-semi-elliptical shape, a triangular shape, a quasi-triangular shape, a square shape, and a quasi-square shape.

[0024] According to one aspect of the present invention, the back external profile and the abdominal external profile are respectively obtained based on the following steps, which include:

[0025] Construct a two-dimensional sectional shape corresponding to the external profile, wherein the basic external profile features of the corresponding external profile are described based on a first type of function, and the basic external profile features are locally corrected by a first shape function to obtain the two-dimensional sectional shape;

[0026] Construct the variation law of the two-dimensional sectional shape along the flow direction, wherein the variation law is constructed based on a second shape function and a second type of function;

[0027] Based on the two-dimensional sectional shape and the variation law, a plurality of external profile sections with different shapes are sequentially discretized in three-dimensional space along the flow direction, and the aerodynamic configuration of the corresponding external profile is fitted based on the external profile sections.

[0028] According to one aspect of the present invention, the two-dimensional sectional shape is expressed as:

[0029] ;

[0030] Wherein, is the first shape function, is the first type of function, , , are respectively , , directionless parameters, is the intermediate function, is the intermediate function;

[0031] The variation law is expressed as:

[0032] ;

[0033] Wherein, is the longitudinal length of the high-density flow front fuselage shell from the front end to the rear end, is the second shape function, is the second type of function, is the first form of function, is the first type of function, is the cross-sectional height, is the cross-sectional width, and and are intermediate functions.

[0034] To achieve the above object of the invention, the present invention provides a front fuselage, comprising: a front fuselage shell and airborne equipment; the front fuselage shell is the aforementioned high-density flow front fuselage shell for an aircraft with abdominal air intake.

[0035] According to one aspect of the present invention, the high-density flow front fuselage shell of the present invention can increase the density flow at the inlet of the air intake on the one hand, and on the other hand, it will not bring excessive costs in terms of structure, volume, resistance, flow loss, etc., effectively ensuring the performance of the aircraft using the present invention while fully reducing its processing difficulty.

[0036] According to one aspect of the present invention, the present invention realizes a high-density flow of the gas at the inlet of the air intake, and after increasing the density flow, it can be mismatched with a three-dimensional internal turning air intake.

[0037] According to one aspect of the present invention, the configuration of the high-density flow front fuselage shell of the present invention has high compression efficiency for the oncoming air flow, small flow loss, and low aerodynamic drag.

[0038] According to one aspect of the present invention, the curved surface for enhancing the density flow in the high-density flow front fuselage shell of the present invention can be integrated with the main body of the front fuselage, and the aerodynamic profile is smooth and round without sharp corners, having advantages in terms of structure implementation, loading efficiency, weight, and heat protection.

[0039] According to one aspect of the present invention, the abdominal outer profile of the present invention performs the first compression on the gas by the pre-compression profile, and the density flow enhancement profile performs the second compression on the gas after the first compression; wherein, the secondary compression process of the gas is carried out based on two dimensions. Firstly, under the transverse compression of the lateral compression surface part, the gas is collected towards the middle. Secondly, the positive compression surface part located in the middle also realizes the three-dimensional compression of the gas. Thus, through the above two compressions, a high-density flow of the gas at the inlet of the air intake is fully realized.

[0040] According to one aspect of the present invention, the fairing surface part provided in the abdominal outer profile of the present invention can be used for the smooth connection between the lateral compression surface part and the back outer profile, effectively reducing the aerodynamic drag. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic perspective view showing a high-density flow front fuselage shell according to an embodiment of the present invention;

[0042] Figure 2 is a front view schematically showing a high-density flow front fuselage shell according to an embodiment of the present invention;

[0043] Figure 3 is a side view schematically showing a high-density flow front fuselage shell according to an embodiment of the present invention;

[0044] Figure 4 is a projected shape diagram schematically showing a pre-compression profile according to an embodiment of the present invention;

[0045] Figure 5 is a projected shape diagram schematically showing a pre-compression profile according to another embodiment of the present invention;

[0046] Figure 6 is a projected shape diagram schematically showing a pre-compression profile according to still another embodiment of the present invention;

[0047] Figure 7 is a structural diagram schematically showing symmetric parts of a plurality of differently shaped outer surface cross-sections discretized from a two-dimensional cross-sectional shape and variation law in an abdominal outer surface according to an embodiment of the present invention;

[0048] Figure 8 is a three-dimensional view schematically showing an outer surface of a high-density flow front fuselage shell fitted according to an embodiment of the present invention;

[0049] Figure 9 is a bottom view schematically showing an outer surface of a high-density flow front fuselage shell fitted according to an embodiment of the present invention;

[0050] Figure 10 is an enlarged view schematically showing a density flow enhanced profile fitted according to an embodiment of the present invention;

[0051] Figure 11 is a bottom view schematically showing a density flow enhanced profile fitted according to an embodiment of the present invention. Specific Embodiments

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0053] When describing the embodiments of the present invention, the orientation or positional relationships expressed by the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" are based on the orientation or positional relationships shown in the relevant drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present invention.

[0054] The present invention will be described in detail below in conjunction with the drawings and specific embodiments. The embodiments cannot be elaborated one by one here, but the embodiments of the present invention are not limited to the following embodiments.

[0055] Combined with Figure 1 、 Figure 2 and Figure 3 As shown, according to an embodiment of the present invention, a high-density flow front fuselage shell for an abdominal air intake aircraft includes: a front fuselage back structure 11 and a front fuselage belly structure 12; in this embodiment, along the longitudinal direction (i.e., the front-rear direction) of the high-density flow front fuselage shell, the front ends of the front fuselage back structure 11 and the front fuselage belly structure 12 are connected to each other; along the lateral direction (i.e., the left-right direction) of the high-density flow front fuselage shell, the left and right ends of the front fuselage back structure 11 are respectively connected to the left and right ends of the front fuselage belly structure 12; thus, a hollow structure with an open rear end is formed between the front fuselage back structure 11 and the front fuselage belly structure 12. In this embodiment, along the direction from the front end to the rear end of the front fuselage back structure 11, the back outer surface 111 of the front fuselage back structure 11 is a convex curved surface that bulges along the normal direction (i.e., the direction perpendicular to the longitudinal and lateral directions); wherein, by setting the back outer surface 111 of the front fuselage back structure 11 as a convex curved surface, the rear end of the high-density flow front fuselage shell is enlarged to facilitate its matching installation with other structures.

[0056] In this embodiment, along the direction from the front end to the rear end of the front fuselage belly structure 12, the belly outer surface 121 of the front fuselage belly structure 12 includes: a pre-compression surface 121a and a high-density flow enhancement surface 122a that are connected in sequence; wherein, a transition structure (wherein, the transition structure can adopt an arc structure or a chamfer structure) is provided at the connection position of the pre-compression surface 121a and the high-density flow enhancement surface 122a. When using an arc transition, connecting the pre-compression surface 121a and the high-density flow enhancement surface 122a with an arc transition at the connection position makes the connection position smoother and rounder, which is more beneficial for ensuring the smooth flow of the air flow; when using a chamfer transition, the shock wave generated by the fold angle is used to quickly compress the air flow, shortening the compression distance.

[0057] Combined with Figure 1 、 Figure 2 andFigure 3 As shown, according to an embodiment of the present invention, along the longitudinal direction of the high-density flow front fuselage shell, the back outer surface 111 and the belly outer surface 121 are respectively axisymmetric surfaces; wherein, the projections of the back outer surface 111 and the belly outer surface 121 are the same.

[0058] Combined with Figure 1 、 Figure 2 and Figure 3 As shown, according to an embodiment of the present invention, the high-density flow enhanced surface 122a includes: a forward compression surface portion 122a1, a lateral compression surface portion 122a2, and a fairing surface portion 122a3; in this embodiment, along the transverse direction of the high-density flow front fuselage shell, the lateral compression surface portion 122a2 is respectively arranged at the left and right ends of the forward compression surface portion 122a1, and the fairing surface portion 122a3 is arranged at one end of the lateral compression surface portion 122a2 away from the forward compression surface portion 122a1. In this embodiment, along the direction from the front end to the rear end of the front fuselage belly structure 12, at least a part of the position where the lateral compression surface portion 122a2 is connected to the fairing surface portion 122a3 protrudes along the normal direction away from the front fuselage back structure 11; wherein, along the direction from the front end to the rear end of the front fuselage belly structure 12, the position where the lateral compression surface portion 122a2 is connected to the fairing surface portion 122a3 can be selected to partially protrude along the normal direction away from the front fuselage back structure 11. Of course, the position where the lateral compression surface portion 122a2 is connected to the fairing surface portion 122a3 can also protrude entirely along the normal direction away from the front fuselage back structure 11.

[0059] Combined with Figure 1 、 Figure 2 and Figure 3 As shown, according to an embodiment of the present invention, along the direction from the front end to the rear end of the front fuselage belly structure 12, the protruding height of the position where the lateral compression surface portion 122a2 is connected to the fairing surface portion 122a3 along the normal direction away from the front fuselage back structure 11 is variable; and, the front width of the lateral compression surface portion 122a2 is greater than its rear width, and the front width of the fairing surface portion 122a3 is less than its rear width. Through the above settings, in the direction from the front end to the rear end of the front fuselage belly structure 12, the combined structure of the lateral compression surface portion 122a2 and the fairing surface portion 122a3 realizes a structure of lateral contraction of the high-density flow front fuselage shell, so that the front fuselage belly structure 12 of the present invention is more likely to achieve enhanced compression of the oncoming flow, while the fairing surface portion 122a3 on the outside is more conducive to the flow of air, which is more beneficial to the rapid and stable flow of air.

[0060] Combined with Figure 1 、 Figure 2 and Figure 3As shown, according to an embodiment of the present invention, along the transverse direction of the high-density flow front fuselage shell, the lateral compression surface portion 122a2 is provided with a connected concave structure 122a21 and convex structure 122a22; wherein, the concave structure 122a21 is arranged adjacent to the forward compression surface portion 122a1; the convex structure 122a22 is arranged adjacent to the fairing surface portion 122a3; along the direction from the front end to the rear end of the front fuselage belly structure 12, the concave structure 122a21 and the convex structure 122a22 are arranged in sequence.

[0061] As Figure 1 shown, according to an embodiment of the present invention, the back external shape surface 111 is generated by one of the CST modeling method, PARSEC method, B-spline curve method, Hicks-Henne basis function method, FFD free deformation method, and streamline tracking method. Correspondingly, the belly external shape surface 121 is generated by one of the CST modeling method, PARSEC method, B-spline curve method, Hicks-Henne basis function method, FFD free deformation method, and streamline tracking method.

[0062] As Figure 1 shown, according to an embodiment of the present invention, the pre-compression profile 121a is one or a combination of a plane, a convex curved surface, and a concave curved surface;

[0063] According to an embodiment of the present invention, the projection of the pre-compression profile 121a is one of an ellipse, a quasi-ellipse (such as Figure 4 ), a triangle, a quasi-triangle (such as Figure 5 ), a square, a quasi-square (such as Figure 6 ).

[0064] Combined with Figure 7 , Figure 8 , Figure 9 , Figure 10 and Figure 11 shown, according to an embodiment of the present invention, the back external shape surface 111 and the belly external shape surface 121 are respectively obtained based on the following steps, which include:

[0065] Construct a two-dimensional sectional shape corresponding to the external shape surface (such as the back external shape surface 111 or the belly external shape surface 121), wherein the basic external shape characteristics of the corresponding external shape surface are described based on the first type of function, and the basic external shape characteristics are locally corrected by the first shape function to obtain the two-dimensional sectional shape; wherein, the two-dimensional sectional shape is expressed as:

[0066] ;

[0067] wherein, is the first shape function, is the first type of function, , , respectively 、 、 direction dimensionless parameters, is an intermediate function, is an intermediate function. In this embodiment, the intermediate function can adopt various forms of functions, such as polynomials, exponentials, logarithms, power functions, trigonometric functions, piecewise functions, etc., and can be selected accordingly according to the specific two-dimensional profile shape.

[0068] In this embodiment, by adjusting the parameters in the two-dimensional profile shape, the structural shapes of various parts of the abdominal external surface 121 (such as the pre-compression surface 121a and the dense flow enhancement surface 122a) can be accurately adjusted. Thus, based on the following variation law, each part can be deformed in the preset interval direction to match the overall shape change of the abdominal external surface 121.

[0069] Construct the variation law of the two-dimensional profile shape along the flow direction, where the variation law is constructed based on the second shape function and the second type of function; where the variation law is expressed as:

[0070] ;

[0071] where, is the longitudinal length of the high-dense flow front fuselage shell from the front end to the rear end (i.e., the length direction is direction), is the second shape function, is the second type of function, is the first shape function, is the first type of function, is the section height, is the section width, 、 、 are intermediate functions, and ; In this embodiment, the intermediate function can adopt various forms of functions, such as polynomials, exponentials, logarithms, power functions, trigonometric functions, piecewise functions, etc., and can be selected accordingly according to the specific two-dimensional profile shape.

[0072] Based on the two-dimensional profile shape and the variation law, a plurality of external surface sections with different shapes are successively discretized in three-dimensional space along the flow direction (see Figure 7 ), and the aerodynamic configuration of the corresponding external surface is fitted based on the external surface section (see Figure 8 、 Figure 9 、 Figure 10 and Figure 11 ).

[0073] According to an embodiment of the present invention, the present invention provides a front fuselage, comprising: a front fuselage shell and airborne equipment; wherein, the front fuselage shell is the high-density flow front fuselage shell for an aircraft with abdominal air intake as described above.

[0074] To further illustrate this solution, further examples are given for elaboration.

[0075] Embodiment 1

[0076] Based on the high-density flow front fuselage shell of the present invention, an optimization design is carried out on the front fuselage of a certain high-speed aircraft. Before and after the optimization design, the overall contours and the air intake ducts of the two configurations remain the same. CFD calculations are carried out for the configurations before and after optimization. Table 1 shows the average dimensionless density flow at the air intake duct inlet, the flow coefficient of the air intake duct, and the total pressure recovery coefficient at the air intake duct outlet under two typical conditions.

[0077] Table 1 Density flow at the air intake duct inlet and air intake duct coefficients before and after optimization using the present invention

[0078]

[0079] As can be seen from Table 1, using the present invention can not only effectively improve the flow capture of the air intake duct, but also has small flow losses.

[0080] The above content is only an example of the specific solution of the present invention. For the equipment and structures not described in detail therein, it should be understood that the existing general equipment and general methods in the art are adopted for implementation.

[0081] The above is only one solution of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-density flow front fuselage shell for a belly-intake aircraft, characterized in that: include: a forward fuselage dorsal structure (11) and a forward fuselage ventral structure (12); Along the longitudinal direction of the high-density flow front fuselage shell, the front end of the front fuselage back structure (11) and the front end of the front fuselage belly structure (12) are connected to each other; Along the lateral direction of the high-density flow front fuselage shell, the left and right ends of the front fuselage back structure (11) are respectively connected to the left and right ends of the front fuselage belly structure (12); Along the direction from the front end to the rear end of the front fuselage back structure (11), the back outer profile surface (111) of the front fuselage back structure (11) is an outward convex curved surface that bulges along the normal direction; Along the direction from the front end to the rear end of the front fuselage belly structure (12), the belly outer profile (121) of the front fuselage belly structure (12) comprises: a pre-compression profile (121a) and a dense flow enhancement profile (122a) connected in sequence; A transition structure is provided at a position where the pre-compression profile (121a) and the dense flow enhancement profile (122a) are connected; The dense flow enhancement surface (122a) comprises: a forward compression surface portion (122a1), a lateral compression surface portion (122a2), and a flow straightening surface portion (122a3); Along the lateral direction of the high-density flow front fuselage shell, the lateral compression surface portion (122a2) is respectively arranged at the left and right ends of the forward compression surface portion (122a1), and the straightening surface portion (122a3) is arranged at one end of the lateral compression surface portion (122a2) away from the forward compression surface portion (122a1); Along the direction from the front end to the rear end of the front fuselage belly structure (12), the position where the lateral compression surface portion (122a2) and the fairing surface portion (122a3) are connected is at least partially protruded in a direction away from the front fuselage back structure (11) in the normal direction; The lateral compression surface portion (122a2) is provided with a concave structure (122a21) and a convex structure (122a22) connected to each other; Along the lateral direction of the high-density flow front fuselage shell, the recessed structure (122a21) is arranged adjacent to the forward compression surface portion (122a1); the raised structure (122a22) is arranged adjacent to the straightening surface portion (122a3); Along the direction from the front end to the rear end of the front fuselage belly structure (12), the recessed structure (122a21) is arranged in front of the raised structure (122a22).

2. The high-density flow front fuselage shell for a belly-intake aircraft according to claim 1, characterized in that: Along the longitudinal direction of the high-density flow front fuselage shell, the back outer profile (111) and the belly outer profile (121) are respectively axisymmetric profiles.

3. The high-density flow front fuselage shell for a belly-intake aircraft according to claim 2, characterized in that: Along the direction from the front end to the rear end of the front fuselage belly structure (12), the protruding height of the position where the lateral compression surface portion (122a2) is connected to the fairing surface portion (122a3) along the direction away from the front fuselage back structure (11) in the normal direction is variable; and the front end width of the lateral compression surface portion (122a2) is greater than the rear end width thereof, and the front end width of the fairing surface portion (122a3) is less than the rear end width thereof.

4. The high-density flow front fuselage shell for a belly-intake aircraft according to claim 3, characterized in that: The back outer profile surface (111) is generated by using one of a CST modeling method, a PARSEC method, a B-spline curve method, a Hicks-Henne basis function method, a FFD free deformation method, and a streamline tracing method; The abdominal outer profile (121) is generated by using one of a CST modeling method, a PARSEC method, a B-spline curve method, a Hicks-Henne basis function method, a FFD free deformation method, and a streamline tracing method.

5. The high-density flow front fuselage shell for a belly-intake aircraft according to claim 4, characterized in that: The pre-compression profile (121a) is a combination of one or more of a plane, a convex curved surface, and a concave curved surface; The projection of the pre-compression profile (121a) is one of a semi-ellipse, a quasi-semi-ellipse, a triangle, a quasi-triangle, a square, and a quasi-square.

6. The high-density flow front fuselage shell for a belly-intake aircraft according to claim 5, characterized in that: The back outer profile (111) and the abdomen outer profile (121) are respectively obtained based on the following steps, which include: Constructing a two-dimensional cross-sectional shape of the corresponding outer profile, wherein the basic outer shape features of the corresponding outer profile are described based on a first-type function, and the basic outer shape features are locally corrected by a first shape function to obtain the two-dimensional cross-sectional shape; Constructing a variation rule of the two-dimensional cross-sectional shape along the flow direction, wherein the variation rule is constructed based on a second shape function and a second type function; Based on the two-dimensional cross-sectional shape and the variation rule, a plurality of external profile sections with different shapes are sequentially discretized in the three-dimensional space along the flow direction, and the aerodynamic configuration of the corresponding external profile is fitted based on the external profile sections.

7. The high-density flow front fuselage shell for a belly-intake aircraft according to claim 6, characterized in that: The two-dimensional cross-sectional shape is expressed as: in, is the first shape function, is a first-class function, , , They are , , The dimensionless parameter of direction, is the intermediate function, is the intermediate function; The variation rule is expressed as: in, It is the longitudinal length of the high-density flow front fuselage shell from the front end to the rear end, is the second shape function, is a second-class function, is the first shape function, is a first-class function, is the section height, is the cross-section width, , , is an intermediate function.

8. A front fuselage, characterized in that: include: A front fuselage shell and airborne equipment; the front fuselage shell is a high-density flow front fuselage shell for a belly-intake aircraft as described in any one of claims 1 to 7.

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