Design method of wing-body fusion waverider based on full three-dimensional bending shock wave

Abstract

A design method for a wing-body-fused waverider based on a full three-dimensional curved shock wave relates to the technical field of near-space hypersonic aircraft design. The full three-dimensional curved shock wave is used as the design shock wave, and the solution is obtained using the local deflection kissing method and the non-coaxial curved characteristic line method to obtain the basic flow field. Given the flow capture profile of the design section, it is projected horizontally forward onto the three-dimensional curved shock wave surface to obtain the waverider's leading edge profile and discretize it. Starting from each discrete point of the leading edge profile, the waverider's lower surface is obtained by streamline tracing. Some of the aforementioned leading edge profile discrete points are selected as the upper surface leading edge points, and the upper surface exit profile is given. The Haack family of curves is then used to generate corresponding profiles within the local kissing surface corresponding to the leading edge point. The resulting profiles are combined to obtain the upper surface of the wing-body-fused waverider. This achieves the design of a wing-body-fused waverider based on a full three-dimensional curved shock wave. This effectively reduces the drag generated by the upper surface, achieving better aerodynamic and stealth performance.

Description

Technical Field

[0001] The present invention relates to the technical field of near-space hypersonic aircraft design, and in particular to a design method for a wing-body fusion waverider based on full three-dimensional curved shock waves. Background Art

[0002] Hypersonic vehicles are capable of sustained flight at hypersonic speeds (i.e., Mach numbers greater than 5) in near-space. Their aerodynamic configurations include conventional aerodynamic shapes and waverider configurations. Waveriders are so named because their lower surface completely "rides" on the shock wave of the leading-edge appendages. From an aerodynamic perspective, the waverider design is the best option for achieving a high lift-to-drag ratio and breaking through the conventional "lift-to-drag barrier."

[0003] Professor Nonweiler (Nonweiler TR F. Aerodynamic problems of manned space vehicles [J]. The Journal of the Royal Aeronautical Society, 1959, 63(585): 521–528.) first proposed the wedge-guided waverider theory in 1959. However, due to problems such as a sharp corner on the lower surface, a large anhedral angle, and insufficient volume ratio, this type of waverider has been difficult to be widely used in engineering practice. To address the above problems, Jones and Moore et al. (Jones JG, Moore KC, Pike J, et al. A method for designing lifting configurations for high supersonic speeds, using axisymmetric flowfields [J]. Archive of Applied Mechanics,, 37(1): 56–72.) proposed the cone-guided waverider theory, and Rasmussen et al. (Rasmussen ML, Jischke MC, Kim B S. Optimization of waverider configurations generated from axisymmetric conical flows [J]. Journal of Spacecraft and Rockets, 1983, 20(5): 461–469.) proved this design theory. Since then, many scholars have further developed the design method of waveriders for given generating bodies, such as the wedge-cone waverider proposed by Takashima and Lewis (Takashima N, Lewis M J. Wedge-cone waverider configuration for engine-airframe interaction [J]. Journal of Aircraft, 1995, 32 (5): 1142–1144.). Although the above-mentioned waverider design method for given generating bodies is simple to calculate and has high accuracy, the shape of the wave it rides on is not controllable, making it difficult to meet the increasingly complex requirements of flight and engine integration design, and therefore the degree of design freedom is not high.

[0004] To further improve the efficiency and flexibility of waverider design, researchers both domestically and internationally have begun studying inverse waverider design methods based on attached shock waves. The most prominent of these methods is the tangent theory, which primarily encompasses tangent cone, tangent axisymmetry, and tangent flow field design theory. In 1990, Sobieczky (Sobieczky H, Dougherty FC, Jones K. Hypersonic waverider design from given shock waves [C] / / First International Waverider Symposium. University of Maryland, 1990: 1–20.) proposed the tangent cone design theory. This design method offers relatively greater freedom in the selection of shock wave shapes, making waverider design more practical. In 1997, Sobieczky and Wang Zhuo et al. (Sobieczky H, Zores B, Zhuo W. High speed flow design using the theory of osculating cones and axisymmetric flows [J]. Chinese Journal of Aeronautics, 1999, 12(1): p. 1-8.) further proposed the osculating axisymmetric theory. In response to the problem that the traditional osculating cone waverider as a precursor has insufficient compression, He Xuzhao et al. proposed the osculating curved cone method based on the osculating axisymmetric theory.

[0005] To date, waverider design methods are still limited to designs based on two-dimensional shock waves, axisymmetric shock waves, and three-dimensional shock waves, lacking consideration of waveriders designed based on full three-dimensional curved shock waves. Designing waveriders using full three-dimensional curved shock waves can greatly expand the design space and design ideas for waveriders. On the other hand, the mainstream design of existing aircraft is a cylindrical wing, which has a cylindrical fuselage and obvious wings. Although this design has certain advantages, it affects the aerodynamic performance, load distribution, and other performance of the aircraft. If a wing-body fusion method is used to design a waverider, it can not only significantly improve aerodynamic and stealth performance, but also reduce noise and fuel consumption costs. Therefore, a wing-body fusion waverider design method based on full three-dimensional curved shock waves is proposed, which can greatly improve the performance of the aircraft. Summary of the Invention

[0006] The present invention aims to address the aforementioned limitations of existing technologies by providing a design method for a wing-body-fused waverider based on full three-dimensional curved shock waves. This method effectively reduces upper surface drag, enabling improved aerodynamic performance and stealth while maintaining volume, while also reducing noise and fuel costs. This approach broadens the scope of waverider design and enhances the design freedom and precision.

[0007] The present invention uses the full three-dimensional curved shock wave as the design shock wave, and uses the local deflection kissing method and the non-coaxial curved characteristic line method to solve it, thereby obtaining the basic flow field. Given the flow capture profile of the design section, it is projected forward horizontally to the three-dimensional curved shock wave surface to obtain the leading edge profile of the waverider and discretize it. Starting from the discrete points of each leading edge profile, the lower surface of the waverider is obtained by streamline tracing. Select the aforementioned discrete points of the leading edge profile as the leading edge points of the upper surface, give the upper surface exit profile, and then use the Haack family curve to generate the corresponding profile within the local kissing surface corresponding to the leading edge point. The obtained profiles are combined to obtain the upper surface of the wing-body fused waverider. In this way, the design of a wing-body fused waverider based on the full three-dimensional curved shock wave is achieved.

[0008] The present invention comprises the following steps:

[0009] 1) According to the volume requirements, the full three-dimensional curved shock wave shape is specified, and the local deflection kissing method and the non-coaxial curved characteristic line method are used to solve the full three-dimensional external compression basic flow field;

[0010] 2) Projecting the flow capture profile of a given design section forward horizontally onto the three-dimensional curved shock wave surface to obtain the waverider leading edge profile and discretize it. Starting from each discrete point, streamlines are traced in the full three-dimensional basic flow field obtained in step 1) to obtain the lower surface of the waverider;

[0011] 3) Selecting some discrete points of the leading edge profile in step 2) as the upper surface leading edge points, giving the upper surface exit profile, and then using the Haack family curve to generate corresponding profiles within the local tangent surface corresponding to the leading edge points, and combining the obtained profiles to obtain the upper surface of the waverider with wing-body fusion;

[0012] 4) The lower surface of the waverider generated in step 2), the upper surface of the wing-body fusion waverider generated in step 3), and the trailing edge surface of the waverider together constitute a wing-body fusion waverider based on a full three-dimensional curved shock wave.

[0013] In step 1), the local deflection kissing method and the non-coaxial bending characteristic line method are used to solve and obtain the full three-dimensional external compression basic flow field. The specific process is:

[0014] The specified full three-dimensional bending shock wave is discretized into a series of infinitesimal tangent planes that deflect with the flow, and all infinitesimal tangent planes starting from the same discrete point are rotated to the same virtual meridian plane through coordinate transformation; the basic flow field in each meridian plane is solved using the non-coaxial bending characteristic line method according to the incoming flow conditions such as the incoming flow Mach number and incoming flow direction; the basic flow field solved in each virtual meridian plane is restored from the meridian plane to the real flow field in the three-dimensional coordinate system, and the full three-dimensional external compression basic flow field is obtained by combining them.

[0015] In step 3), some discrete points of the leading edge profile in step 2) are selected as the leading edge points of the upper surface, and the upper surface exit profile is given. Then, corresponding profiles are generated within the local tangent surface corresponding to the leading edge points using the Haack family curve. The obtained profiles are combined to obtain the upper surface of the wing-body fused waverider body. The specific method is as follows:

[0016] According to the required volume, a series of discrete points of the leading edge profile in step 2) are selected as the leading edge points of the wing-body fusion upper surface, and the flow velocity vector and the normal velocity vector at the discrete shock wave points jointly determine the local kissing surface where the points are located; given the exit profile of the wing-body fusion upper surface of the waverider, it is discretized into each kissing surface to obtain the trailing edge point of the upper surface profile in each kissing surface; according to the positions of the leading edge point and the trailing edge point in each local kissing surface, a Haack family curve that meets the volume requirements is selected as the profile of the wing-body fusion upper surface in the kissing surface; the profiles obtained in each kissing surface are combined to obtain the upper surface of the waverider with wing-body fusion.

[0017] Advantages of the present invention: The wing-body fusion waverider based on a fully three-dimensional curved shock wave is generated using a local deflection kissing method and a non-coaxial bending characteristic line method to generate its lower surface. The design considers changes in shock wave intensity, three-dimensional reconstruction of the shock wave curved surface, and lateral flow, effectively expanding the precision and degrees of freedom of this type of waverider design. The upper surface utilizes a wing-body fusion method, making the fuselage and wings form a single unit. This effectively reduces the drag generated by the upper surface, enabling improved aerodynamic performance and stealth while maintaining volume, and reducing noise and fuel consumption costs of the waverider aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of solving the basic flow field based on full three-dimensional curved shock waves using the local deflection kissing method.

[0019] Figure 2 It is a schematic diagram of the solution of the upper surface of the wing-body fusion waverider based on the full three-dimensional bending shock wave.

[0020] Figure 3 It is a Haack family curve graph.

[0021] Figure 4 This is one of the overall schematic diagrams of the wing-body fusion waverider based on full three-dimensional shock waves.

[0022] Figure 5 This is the second overall schematic diagram of the wing-body fusion waverider based on full three-dimensional shock waves.

[0023] The marks in the figure are:

[0024] 1 represents the leading edge discrete point of the lower surface of the waverider, 2 represents the flow velocity vector at the discrete point of the shock wave, 3 represents the infinitesimal kissing surface, 4 represents the lower surface of the waverider generated based on the full three-dimensional curved shock wave, 5 represents the profile of the lower surface of the waverider, 6 represents the flow capture profile (i.e., FCT line) of the waverider, 7 represents the three-dimensional shock wave surface, 8 represents the normal velocity vector at the discrete point of the shock wave, 9 represents the profile of the upper surface of the wing-body fusion, 10 represents the exit profile of the upper surface of the wing-body fusion, 11 represents the trailing edge point of the upper surface profile, 12 represents the upper surface of the waverider of the wing-body fusion, 13 represents the local kissing surface of the upper surface of the wing-body fusion, and 14 represents the trailing edge surface of the waverider. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following embodiments will be further described in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. On the contrary, the present invention encompasses any substitutions, modifications, equivalent methods and solutions made within the spirit and scope of the present invention as defined by the claims. Furthermore, in order to provide the public with a better understanding of the present invention, certain specific details are described in detail in the following detailed description of the present invention. Those skilled in the art can fully understand the present invention without the description of these details.

[0026] The wing-body fusion waverider solution based on full three-dimensional bending shock wave of the present invention mainly includes the waverider lower surface 4 generated based on full three-dimensional bending shock wave, the wing-body fusion waverider upper surface 12 and the waverider trailing edge surface 14. The above three together constitute the following Figure 4 The wing-body fusion waverider based on full three-dimensional bending shock wave is shown.

[0027] The main implementation steps of the wing-body fusion waverider design method based on full three-dimensional bending shock waves include:

[0028] (1) See Figure 1 Given a three-dimensional shock wave surface 7, the local deflection kissing method is used to discretize the three-dimensional shock wave surface into a series of infinitesimal kissing surfaces 3 that deflect with the flow. Through coordinate transformation, the series of infinitesimal kissing surfaces 3 starting from the leading edge discrete point 1 on the lower surface of the same waverider are rotated to the same virtual meridian plane.

[0029] Based on the incoming flow conditions such as the incoming flow Mach number and incoming flow direction, the non-coaxial curved characteristic line method is used to solve the basic flow field in each virtual meridian plane. The governing equations of the non-coaxial curved characteristic line method are as follows:

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] Where p is pressure, δ is flow angle, μ is Mach angle, ρ is density, V is stream velocity, w is circumferential velocity, γ is specific heat ratio, j is judgment factor, s is streamline, l is characteristic line, φ is circumferential angle, P is the derivative of pressure along streamline, and D is the derivative of flow angle along streamline.

[0039] The basic flow field in each meridian plane obtained by the solution is restored to the real flow field in the three-dimensional coordinate system through the local deflection kissing method, and the full three-dimensional external compression basic flow field is obtained.

[0040] (2) Figure 1 As shown, given the flow capture profile 6 within the design cross section, it is horizontally projected against the incoming flow direction onto the three-dimensional shock wave surface 7, and the intersection of the two yields the leading edge profile of the waverider. The leading edge profile of the waverider is discretized to obtain a series of discrete leading edge points 1 of the waverider. Starting from each discrete point 1, streamlines are traced in the full three-dimensional external compression basic flow field obtained in step (1) to obtain a series of streamlines, which are used as a series of profiles 5 on the lower surface of the waverider. The lower surface 4 of the waverider is obtained by combining them. The flow capture profile can be an arbitrary curve such as a conic section.

[0041] (3) Figure 2 As shown in FIG, according to the volume requirement, a series of discrete points 1 in step (2) are selected as the leading edge points of the wing-body fusion upper surface, and the streamwise velocity vector 2 and the normal velocity vector 8 at the shock wave discrete points jointly determine the local kissing surface 13 where they are located. Given the exit profile 10 of the wing-body fusion upper surface of the waverider, it is discretized into each kissing surface, and the trailing edge point 11 of the upper surface profile within each kissing surface is obtained.

[0042] Among them, the Haack family curve is defined as:

[0043]

[0044]

[0045] According to the position of the leading edge point and the trailing edge point in each kissing surface, select Figure 3 The Haack family curve that meets the volume requirement is used as the corresponding wing-body fusion upper surface profile 9 within the kissing surface. By combining all the profiles, the wing-body fusion upper surface 12 of the waverider body can be obtained.

[0046] See also Figure 4 and 5 The waverider lower surface 4, the wing-body fusion upper surface 12 and the waverider trailing edge surface 14 generated based on the full three-dimensional bending shock wave together constitute a wing-body fusion waverider based on the full three-dimensional bending shock wave.

Claims

1. The design method of wing-body fusion waverider based on full three-dimensional bending shock wave is characterized by The following steps are involved: 1) According to the volume requirements, the full three-dimensional curved shock wave shape is specified, and the local deflection kissing method and the non-coaxial curved characteristic line method are used to solve the full three-dimensional external compression basic flow field. The specific process is as follows: The specified full three-dimensional curved shock wave is discretized into a series of micro-element tangent planes that deflect with the flow, and all micro-element tangent planes starting from the same discrete point are rotated to the same virtual meridian plane through coordinate transformation. The basic flow field in each meridian plane is solved using the non-coaxial curved characteristic line method according to the incoming flow Mach number and direction. The basic flow field solved in each virtual meridian plane is restored from the meridian plane to the real flow field in the three-dimensional coordinate system, and the full three-dimensional external compression basic flow field is obtained by combining them. 2) Project the flow capture profile of the given design section forward horizontally onto the three-dimensional curved shock wave surface to obtain the waverider leading edge profile and discretize it. Streamline tracing is performed along each discrete point in the full three-dimensional basic flow field obtained in step 1) to obtain the waverider lower surface; 3) Selecting some discrete points of the leading edge profile in step 2) as the leading edge points of the upper surface, giving the upper surface exit profile, and then using the Haack family curve to generate corresponding profiles in the local kissing surface corresponding to the leading edge point, and combining the obtained profiles to obtain the upper surface of the waverider with wing-body fusion. The specific method is: according to the required volume, select a series of discrete points of the leading edge profile in step 2) as the leading edge points of the wing-body fusion upper surface, and determine the local kissing surface where the shock wave discrete points are located by the flow velocity vector and the normal velocity vector at the shock wave discrete point; given the exit profile of the wing-body fusion upper surface of the waverider, discretize it into each kissing surface to obtain the trailing edge point of the upper surface profile in each kissing surface; according to the positions of the leading edge point and the trailing edge point in each local kissing surface, select the Haack family curve that meets the volume requirements as the profile of the wing-body fusion upper surface in the kissing surface; and combine the profiles obtained in each kissing surface to obtain the upper surface of the waverider with wing-body fusion; 4) The lower surface of the waverider generated in step 2), the upper surface of the wing-body fusion waverider generated in step 3), and the trailing edge surface of the waverider together constitute a wing-body fusion waverider based on a full three-dimensional bending shock wave.

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