Design method of curve head double-sweepback osculating cone waverider without transition section and related device

Abstract

The invention discloses a design method of a curve head double-sweepback osculating cone waverider without a transition section and a related device, the curve head of the waverider is formed by intersection of two front edges, each front edge is composed of two straight line segments without a transition section in the middle, the first straight line segment starting from the cuspidal point of the curve head corresponds to a first sweepback angle, and the second straight line segment starting from the cuspidal point of the curve head corresponds to a second sweepback angle; the second straight line segment corresponds to a second sweepback angle, and the angle of the two sweepback angles is controllable in the design stage. A stable separation vortex is generated on the upper surface through the double-sweepback-angle-controllable linear front edge, so that the aerodynamic performance of the upper surface is improved without sacrificing the volume efficiency of the aircraft; the design without a transition section is adopted, so that the front edge of the whole waverider is completely controllable in the design stage, airflow separation and vortex generation are reduced, the aerodynamic resistance is effectively reduced, the machining difficulty in engineering is effectively reduced, and the stability of the whole structure is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft aerodynamic shape, and in particular to a design method and related device for a double-swept osculating cone waverider with a curved head and no transition section. Background Art

[0002] Hypersonic aircraft refers to an aircraft with a flight Mach number greater than 5, powered by an air-breathing engine or a combination of engines or without power, and capable of long-distance flight in the atmosphere and across the atmosphere. Its application forms include hypersonic cruise missiles, hypersonic gliders, hypersonic manned / unmanned aircraft, space planes, hypersonic wide-speed range aircraft and other aircraft.

[0003] When a traditional aircraft flies at hypersonic speed, the maximum lift-to-drag ratio and the flight Mach number have the following relationship: ,in is the flight Mach number. From the above formula, we can see that the maximum lift-to-drag ratio of the traditional layout can only reach about 4 at high Mach numbers, that is, there is a "lift-to-drag ratio barrier". The waverider can break the "lift-to-drag ratio barrier" of the traditional layout. The relationship between the maximum lift-to-drag ratio and the flight Mach number of the waverider layout aircraft is: , the above formula shows that when the waverider is arranged at a high Mach number, the maximum lift-to-drag ratio can reach about 6. The reason why the waverider has such a good lift-to-drag ratio is that when the aircraft is flying in the design state, the shock wave is completely attached to the leading edge, just like riding on the shock wave surface, so it is called a "waverider". In this flow field, the flow on the lower surface is restricted by the attached shock wave and does not leak to the upper surface. For the traditional layout, this leakage of the upper and lower surfaces can cause up to 25% lift loss. Although the generation and design methods of waveriders have been studied in depth, there are still the following problems: First, volumetric efficiency and lift-to-drag ratio are contradictory, and they must be weighed during design; second, the upper surface design is difficult. Designing it as an expansion surface can improve aerodynamic performance but reduce volumetric efficiency. Designing it as a compression surface can improve volumetric efficiency but reduce aerodynamic performance. At present, it is generally designed as a free stream surface, which does not contribute to aerodynamic performance and volumetric efficiency; third, the non-design state, especially the low-speed performance is poor, because the waverider can only ride the wave in the design state.

[0004] The Chinese patent with publication number CN107253521B discloses a double-swept osculating cone waverider with a curved head and a transition section. While ensuring that the volume efficiency is not reduced, the swept leading edge is used to generate a stable separation vortex on the upper surface, thereby improving the lift of the waverider at a positive angle of attack (non-design state). This performance is effective at both low and high speeds. At the same time, adding an outer wing with a smaller swept angle on the basis of a single swept back can increase the plane area and improve the low-speed performance. However, since the waverider design method uses a transition section to connect the corresponding leading edges of the two swept back sections, and the numerical approximation is performed by interpolation, it cannot be fully controlled in the design stage. Summary of the invention

[0005] The present invention provides a design method and related device for a curved head double-swept osculating cone waverider without a transition section, which is used to solve the technical problem that the existing waverider design method adopts a transition section to connect the corresponding leading edges of two swept sections, and uses interpolation to approximate numerical values, which cannot be fully controlled in the design stage, thereby increasing the difficulty of engineering processing.

[0006] A first aspect of the present invention provides a design method for a double-swept osculating cone waverider with a curved head without a transition section, wherein the curved head of the waverider is formed by the intersection of two leading edges, each of which is composed of two straight line segments connected without a transition section in the middle; the method comprises:

[0007] Based on the preset cruise Mach number, the preset waverider fuselage length and the preset curved head fuselage length, the shock angle and the sweep angle parameters of the waverider are solved;

[0008] Determining a flow capture tube curve and a flow capture tube curved surface according to the preset waverider body length, the preset curved head body length, the shock wave angle and the sweep angle parameters;

[0009] Based on the shock wave angle, the sweep angle parameter, the preset curve head fuselage length, the flow capture tube curve and the flow capture tube surface, an intake capture curve is constructed; wherein the intake capture curve is composed of a circular arc and two straight line segments connected in sequence;

[0010] Performing a discretization operation on the intake capture curve to obtain a plurality of target osculating planes, and solving the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane;

[0011] Taking the leading edge point of the waverider as the starting point, streamline tracking is performed in the osculating cone flow field to the plane where the intake capture curve is located; the lower surface of the waverider is composed of all streamlines associated with the osculating cone flow field, and singular problem detection is performed on the lower surface of the waverider to update the lower surface of the waverider;

[0012] Starting from the leading edge point of the waverider body, streamline tracing is performed in the free flow field to the plane where the intake capture curve is located, and the upper surface of the waverider body is composed of all streamlines associated with the free flow field.

[0013] Furthermore, it also includes:

[0014] Under the preset flight altitude and preset waverider fuselage length, the lift-to-drag ratio of the waverider is calculated by the reference temperature method through the inviscid flow field information provided by the osculating cone flow field, and the volumetric efficiency of the waverider is calculated by combining the viscous force calculation method of the compressed plate.

[0015] Furthermore, the sweep angle parameter also includes a fuselage length corresponding to the first sweep angle; the step of determining the flow capture tube curve and the flow capture tube surface according to the preset waverider fuselage length, the shock wave angle and the sweep angle parameter includes:

[0016] According to the preset waverider fuselage length, the shock wave angle, the first sweep angle, the second sweep angle and the fuselage length corresponding to the first sweep angle, the fuselage width corresponding to the curved head, the fuselage width corresponding to the first sweep angle and the fuselage width corresponding to the second sweep angle are calculated;

[0017] The sum of the fuselage width corresponding to the head of the curve, the fuselage width corresponding to the first sweep angle and the fuselage width corresponding to the second sweep angle is taken as the length of the flow capture tube curve, and a horizontal straight line segment is used to construct the flow capture tube curve;

[0018] The flow capture tube surface is determined from the flow capture tube curve.

[0019] Furthermore, the process of constructing the intake capture curve specifically includes:

[0020] The arc is set on the side close to the symmetry plane of the waverider fuselage, and the parameters of the arc are calculated and determined by the preset waverider fuselage length, shock wave angle, first sweep angle and preset curve head fuselage length; two straight line segments are set on the side away from the symmetry plane of the waverider fuselage; wherein one end of the first straight line segment is connected to one end of the arc, and the first-order derivative continuity is ensured at the connection point; the other end of the first straight line segment is connected to one end of the second straight line segment; the other end of the second straight line segment is connected to one end of the flow capture tube curve away from the symmetry plane of the waverider fuselage, and the connection point forms a certain angle in the horizontal direction;

[0021] Extend two straight line segments respectively, and discretize the circular arc and the two straight line segments into a series of discrete points, and use each discrete point as the normal line; use a series of planes that pass through the normal line and are perpendicular to the plane where the circular arc and the two straight line segments are located as multiple initial osculating planes; wherein the extension end points of the two straight line segments must meet the following conditions: the intersection of the initial osculating planes corresponding to the two straight line segments is located on the curved surface of the flow capture tube, and the osculating cone radii corresponding to the two straight line segments are equal in length;

[0022] The lengths of the two straight line segments of the intake capture curve are calculated through the geometric constraint relationship between the extended end points of the two straight line segments and the flow capture tube curve and the initial osculating plane, thereby determining the intake capture curve.

[0023] Furthermore, the step of forming the lower surface of the waverider body by all streamlines associated with the osculating cone flow field, and performing singular problem detection on the lower surface of the waverider body to update the lower surface of the waverider body comprises:

[0024] The lower surface of the waverider is composed of all streamlines associated with the osculating cone flow field;

[0025] Performing singular problem judgment on the lower surface of the waverider to determine whether there is an intersection problem or a gap problem on the lower surface of the waverider;

[0026] If the lower surface of the waverider body has an intersection problem, the planes formed by the streamlines corresponding to the two swept sections are intersected to delete the redundant surfaces other than the intersection line, and the remaining surfaces are retained to form the lower surface of the waverider body, and then the intersection line is locally smoothed to ensure the continuity of the function or function derivative at the intersection line according to the preset specific requirements;

[0027] If there is a gap problem on the lower surface of the waverider body, the swept corresponding plane located below the space is extended in the direction of another extended swept corresponding plane, and the extended swept corresponding plane is intersected with the other extended swept corresponding plane to delete the redundant surfaces outside the intersection line, and the remaining surfaces are retained to form the lower surface of the waverider body, and then the intersection line is locally smoothed to ensure the continuity of the function or function derivative at the intersection line according to preset specific requirements.

[0028] Furthermore, the step of performing a discrete operation on the intake capture curve to obtain a plurality of target osculating planes, and solving the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane comprises:

[0029] Discretize the air intake capture curve into a series of discrete points, and use a normal line through each discrete point; and use a series of planes that pass through the normal line and are perpendicular to the plane where the air intake capture curve is located as multiple target osculating planes;

[0030] Determine the projection point of the occluding cone vertex in each target occluding plane, and determine the occluding cone vertex of each target occluding plane according to the shock wave angle, the corresponding discrete points on the intake capture curve and the projection point of the occluding cone vertex; solve and obtain the occluding cone flow field in each target occluding plane according to the preset cruise Mach number, the shock wave angle and the occluding cone vertex of each target occluding plane;

[0031] The leading edge point of the waverider for each target osculating plane is determined by the intersection of the flow capture tube and the shock surface.

[0032] The second aspect of the present invention further provides a design system for a curved head double-swept osculating cone waverider without a transition section, the system comprising:

[0033] A shape parameter solving unit is used to solve the shock angle and sweep angle parameters of the waverider based on a preset cruise Mach number, a preset waverider fuselage length and a preset curved head fuselage length;

[0034] A flow capture tube determination unit, used to determine a flow capture tube curve and a flow capture tube curved surface according to the preset waverider fuselage length, the preset curved head fuselage length, the shock wave angle and the sweep angle parameters;

[0035] An air intake capture curve construction unit, used to construct an air intake capture curve based on the shock wave angle, the sweep angle parameter and the preset curve head fuselage length, the flow capture tube curve and the flow capture tube curved surface; wherein the air intake capture curve is composed of a circular arc and two straight line segments connected in sequence;

[0036] a target osculating plane determining unit, configured to perform a discrete operation on the intake capture curve to obtain a plurality of target osculating planes, and to solve the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane;

[0037] The lower surface generating unit of the waverider is used for taking the leading edge point of the waverider as the starting point, performing streamline tracking in the osculating cone flow field, and tracking to the plane where the intake capture curve is located; forming the lower surface of the waverider from all streamlines associated with the osculating cone flow field, and performing singular problem detection on the lower surface of the waverider to update the lower surface of the waverider;

[0038] The upper surface generating unit of the waverider is used to perform streamline tracing in the free flow field starting from the leading edge point of the waverider to the plane where the intake capture curve is located, and the upper surface of the waverider is composed of all streamlines associated with the free flow field.

[0039] The third aspect of the present invention also provides a computer device, including a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the above-mentioned design methods.

[0040] A fourth aspect of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described design methods.

[0041] A fifth aspect of the present invention also provides a computer program product, comprising a computer program, which implements the steps of any of the above-mentioned design methods when executed by a processor.

[0042] It can be seen from the above technical solutions that the present invention has the following advantages:

[0043] The present invention provides a design method and related device of a double-swept osculating cone waverider with a curved head without a transition section, wherein the curved head of the waverider is composed of two intersecting leading edges, and each leading edge is composed of two straight line segments connected without a transition section in the middle.

[0044] The design method includes: solving the shock wave angle and sweep angle parameters of the waverider based on the preset cruise Mach number, the preset waverider fuselage length and the preset curve head fuselage length; determining the flow capture tube curve and the flow capture tube surface according to the preset waverider fuselage length, the preset curve head fuselage length, the shock wave angle and the sweep angle parameters; constructing the intake capture curve based on the shock wave angle, the sweep angle parameters and the preset curve head fuselage length, the flow capture tube curve and the flow capture tube surface; wherein the intake capture curve is composed of a circular arc and two straight line segments connected in sequence; and separating the intake capture curve. The osculating cone flow field and the leading edge point of the waverider are obtained by scattering operation, and the osculating cone flow field and the leading edge point of the waverider of each target osculating plane are solved; starting from the leading edge point of the waverider, streamlines are traced in the osculating cone flow field to the plane where the intake capture curve is located; all streamlines associated with the osculating cone flow field constitute the lower surface of the waverider, and singular problem detection is performed on the lower surface of the waverider to update the lower surface of the waverider; starting from the leading edge point of the waverider, streamlines are traced in the free flow field to the plane where the intake capture curve is located, and all streamlines associated with the free flow field constitute the upper surface of the waverider.

[0045] In the present invention, a transition-free design is adopted between the two corresponding swept leading edges, so that the leading edge of the entire waverider body is fully controllable in the design stage, reducing the airflow separation and the generation of vortices, thereby effectively reducing the aerodynamic drag, and also effectively reducing the engineering processing difficulty and ensuring the stability of the overall structure, thereby improving the flight performance of the waverider body. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0047] Figure 1 A flowchart of the steps of a design method of a double-swept osculating cone waverider with a curved head without a transition section provided by an embodiment of the present invention;

[0048] Figure 2 A free view of a waverider provided by an embodiment of the present invention;

[0049] Figure 3 A top view and a schematic diagram of the geometric relationship of a waverider provided in an embodiment of the present invention;

[0050] Figure 4 A rear view and a schematic diagram of the geometric relationship of a waverider provided by an embodiment of the present invention;

[0051] Figure 5 A schematic diagram of the geometric relationship between two straight line segments of an intake capture curve provided in an embodiment of the present invention at a connection point;

[0052] Figure 6 The embodiment of the present invention provides Figure 4 A schematic diagram showing discrete points, normal lines and projection points of osculating cone vertices is provided on the basis;

[0053] Figure 7 A schematic diagram of solving the osculating cone vertex provided by an embodiment of the present invention;

[0054] Figure 8 A schematic diagram of the waveriding characteristics of a waverider provided as an example of the present invention;

[0055] Fig. 9 A structural block diagram of a design system for a curved head double-swept osculating cone waverider without a transition section provided by an embodiment of the present invention;

[0056] Among them, the figure markings are: lower surface of waverider 1, intake capture curve 2, shock wave surface 3, curve head 4, curve head leading edge 5, first section swept leading edge 6 and second section swept leading edge 7. DETAILED DESCRIPTION

[0057] The embodiment of the present invention provides a design method and related device for a curved head double-swept osculating cone waverider with no transition section, which is used to solve the technical problem that the existing waverider design method uses a transition section to connect the corresponding leading edges of the two swept sections, and uses interpolation to approximate numerically, which cannot be fully controlled in the design stage, thereby increasing the difficulty of engineering processing.

[0058] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] See also Figure 1 The present invention provides a design method for a double-swept osculating cone waverider with a curved head and no transition section.

[0060] See also Figure 2 The curved head 4 of the waverider provided in this embodiment is composed of two leading edges intersecting each other, each leading edge is composed of two straight line segments connected without a transition segment in the middle, the first straight line segment starting from the sharp point of the curved head 4 corresponds to the first sweep angle, and the second straight line segment corresponds to the second sweep angle, and the angles of the two sweep angles are controllable in the design stage;

[0061] Specifically, the design method of the double-swept osculating cone waverider with a curved head without a transition section includes:

[0062] Step 101, based on a preset cruise Mach number, a preset waverider fuselage length, and a preset curved head fuselage length, solve the shock angle and sweep angle parameters of the waverider.

[0063] It should be noted that the preset cruise Mach number is determined according to design requirements. , preset waverider fuselage length and preset curve head body length ; Among them, the preset waverider fuselage length like Figure 3 As shown in PW, the preset curve head fuselage length Corresponding to the front edge 5 of the curved head, the front edge 5 of the curved head is as follows Figure 3 As shown in WV; the sweep angle parameters include the first sweep angle , Second sweep angle Fuselage length corresponding to the first sweep angle .

[0064] Specifically, the process of determining the parameters in the waverider is as follows:

[0065] 1) Determine the first sweep angle : Based on the cruise Mach number Determine the upper limit of the sweep angle of the waverider, and then select a reasonable sweep angle according to the design requirements; the formula for determining the range of the sweep angle is: Specifically, the first sweep angle λ1 is as follows: Figure 3 As shown, the first swept leading edge 6 of the waverider is shown as VM in the figure.

[0066] 2) Determine the second sweep angle : Second sweep angle The range of changes needs to meet: , and then select a reasonable sweep angle according to the design requirements; specifically, the second sweep angle like Figure 3 As shown, the second swept leading edge 7 of the waverider is shown as MC in the figure.

[0067] 3) Determine the shock wave angle β: from the cruise Mach number and first sweep angle Determine the range of shock wave angle, that is: , and then select a reasonable shock wave angle according to design requirements.

[0068] 4) Determine the fuselage length corresponding to the first sweep angle :Based on the preset waverider fuselage length and preset curve head body length Determine the fuselage length corresponding to the first sweep angle .

[0069] Step 102, determining a flow capture tube curve and a flow capture tube surface according to preset waverider fuselage length, shock angle, sweep angle parameters and preset curve head fuselage length.

[0070] In this step, the process of determining the flow capture tube curve includes: according to the preset waverider fuselage length , preset curve head body length , shock angle , first sweep angle , Second sweep angle Fuselage length corresponding to the first sweep angle , calculate the fuselage width corresponding to the curved head , the fuselage width corresponding to the first sweep angle The fuselage width corresponding to the second sweep angle ; The width of the fuselage corresponding to the curved head , the fuselage width corresponding to the first sweep angle The fuselage width corresponding to the second sweep angle The sum is taken as the length of the flow capture tube curve. In order to ensure that a straight front edge is obtained, a horizontal straight line segment is used to construct the flow capture tube curve.

[0071] Among them, see Figure 3 and Figure 4 The flow capture tube curve is shown as the horizontal straight segment PABC in the figure; the line segment PA corresponds to the front edge 5 of the curve head, and the length is ; Line segment AB corresponds to the first swept leading edge 6, and its length is ; Line segment BC corresponds to the second swept leading edge 7, and its length is ;

[0072] In order to simplify the calculation, an auxiliary coefficient is set: ; , and They are calculated by the following formulas respectively:

[0073]

[0074]

[0075]

[0076] At this point, the entire flow capture tube curve can be obtained. The length of this curve is the overall fuselage width, which is given by Indicates that .

[0077] Then, the flow capture tube surface is determined by the flow capture tube curve, wherein the flow capture tube surface is determined by the flow capture tube curve, a projection curve of the flow capture tube on the plane where the bottom of the waverider body is located.

[0078] Step 103, constructing an air intake capture curve 2 based on the shock wave angle, the sweep angle parameters and the preset curve head fuselage length, the flow capture tube curve and the flow capture tube surface; wherein the air intake capture curve 2 is composed of a circular arc and two straight line segments connected in sequence.

[0079] In this embodiment, the intake air capture curve 2 is as follows: Figure 4 As shown in the curve segment DEFC, DE is an arc segment corresponding to the head segment of the curve, and point U is the center of the arc; EF and FC are two straight line segments, corresponding to the first swept leading edge 6 and the second swept leading edge respectively.

[0080] The specific construction process of the intake capture curve 2 includes:

[0081] Sub-step 1031, setting the arc on the side close to the symmetry plane of the waverider body, the parameters of the arc are determined by the preset waverider body length , shock wave angle β, first sweep angle and preset curve head body length Calculate and determine; set two straight line segments on the side away from the symmetry plane of the waverider body; wherein, one end of the first straight line segment is connected to one end of the arc, and the first-order derivative continuity is ensured at the connection point; the other end of the first straight line segment is connected to one end of the second straight line segment; the other end of the second straight line segment is connected to one end of the flow capture tube curve away from the symmetry plane of the waverider body, and the connection forms a certain angle in the horizontal direction.

[0082] It can be understood that the waverider fuselage is symmetrically designed, and the symmetry plane of the waverider fuselage refers to the plane formed on the longitudinal axis in the forward direction of the fuselage, that is, the symmetry plane of the left and right sides of the fuselage about the middle.

[0083] See also Figure 4 The parameters of the arc include the radius R of the arc DE, the central angle γ1 corresponding to the arc, and the distance between the point P of the flow capture tube curve and the point D of the arc. , the specific calculation process is as follows:

[0084]

[0085] In addition, in order to ensure that the waverider head is designed in a curved shape, the distance between the center of the arc segment of the air intake capture curve 2 and the end point of the flow capture curve on the symmetry plane, that is, the center deviation distance, needs to be considered during the design. Maintaining this distance helps to improve the aerodynamic efficiency of the waverider head, thereby improving the lift-to-drag ratio of the waverider.

[0086] Since the endpoint E of the straight line segment EF is tangent to the arc, the angle between the straight line segment EF and the horizontal direction is also γ 1 ; Set the angle between the straight line segment FC and the horizontal direction to γ 2 , γ 2 The calculation method is: .

[0087] Sub-step 1032, respectively extend the two straight line segments, and discretize the circular arc and the two straight line segments into a series of discrete points, and use each discrete point as the normal; use a series of planes that pass through the normal and are perpendicular to the plane where the circular arc and the two straight line segments are located as multiple initial osculating planes; wherein, the extended end points of the two straight line segments must meet the following conditions: the intersection of the initial osculating planes corresponding to the two straight line segments is located on the flow capture tube surface, and the osculating cone radii corresponding to the two straight line segments are equal in length.

[0088] Among them, the intersection line of the initial osculating planes corresponding to the two straight line segments is located on the flow capture tube surface, which can ensure that the leading edge of the waverider body can achieve a transition-free connection between the two swept leading edges.

[0089] Sub-step 1033, the lengths of the two straight line segments of the intake capture curve 2 are calculated through the geometric constraint relationship between the extended end points of the two straight line segments and the flow capture tube curve and the initial osculating plane, thereby determining the intake capture curve 2.

[0090] exist Figure 5 middle, Indicates the extended end point of the first straight line segment, Indicates the extended end point of the second straight line segment, O 1 express The corresponding osculating cone center, O 2 express The corresponding osculating cone center, B represents the line segment L 1 O 1 With line segment L 2 O 2 Intersection point on the flow capture tube curve.

[0091] Also, for ease of calculation, see Figure 4 and Figure 5 , this embodiment constructs auxiliary variables: , , , , , , and ;in, Represents line segment BO 1 Length, Represents line segment BL 1 Length, Represents line segment BO 2 length, Represents line segment BL 2 Length; Represents line segment BL 1 The angle with the flow capture tube curve, represents the angle between the flow capture tube curve and the straight line segment FC, Represents line segment BL 1 The angle with line segment BF, Represents line segment BL 2 The angle between the line segment BF and the line segment BF. These auxiliary variables satisfy the following preset geometric constraints:

[0092]

[0093] It can be understood that the radius length of the osculating cone between two straight line segments (i.e. and ) are equal, the extension end points of the two straight line segments are Figure 5 L 1 and L 2 The corresponding osculating cone radius also needs to satisfy BL 1 =BL 2 and BO 1 =BO 2 , which can ensure that the leading edge lines corresponding to the swept ends of the waverider body intersect at one point in the flow capture surface, and according to BL 1 =BL 2 and BO 1 =BO 2 The geometric constraints and Figure 5 The remaining geometric relationships in can determine the lengths of the two straight line segments of the intake capture curve 2.

[0094] From this, we can calculate:

[0095]

[0096] Then, the line segment and line segments The lengths are calculated by the following formulas:

[0097]

[0098]

[0099] The length of the straight line segment EF corresponding to the first swept leading edge in the intake capture curve 2 is:

[0100]

[0101] The length of the straight line segment FC corresponding to the second swept leading edge in the intake capture curve 2 is:

[0102]

[0103] At this point, the entire intake capture curve 2 is obtained.

[0104] The straight sections of the air intake capture curve 2 and the flow capture tube curve ensure that the leading edge of the waverider body forms two straight leading edges. At the same time, a transition-free design is adopted between the two straight sections of the air intake capture curve 2. This can ensure that the straight leading edge is fully controllable during design, reduce airflow separation and the generation of vortices, thereby effectively reducing aerodynamic resistance, and also effectively reducing the difficulty of engineering processing and ensuring the stability of the overall structure.

[0105] Step 104 , performing a discretization operation on the intake capture curve 2 to obtain a plurality of target osculating planes, and solving the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane.

[0106] This step specifically includes the following sub-steps:

[0107] Sub-step 1041, discretize the air intake capture curve 2 into a series of discrete points, and use each discrete point as a normal line; and use a series of planes that pass through the normal line and are perpendicular to the plane where the air intake capture curve 2 is located as multiple target osculating planes. Figure 6 , discrete points such as " ”, and the normal is shown as the dotted line in the figure.

[0108] Sub-step 1042, determining the projection point of the occluding cone vertex in each target occluding plane, and determining the occluding cone vertex of each target occluding plane based on the shock wave angle, the corresponding discrete points on the intake capture curve 2 and the projection point of the occluding cone vertex; based on the preset cruise Mach number, shock wave angle and the occluding cone vertex of each target occluding plane, solving to obtain the occluding cone flow field in each target occluding plane.

[0109] See also Figure 6 , the projection point of the vertex of the osculating cone is shown in the figure " As shown in the figure; in the process of determining the projection point of the vertex of the osculating cone in each target osculating plane, for an arc segment, the projection point of the vertex of the osculating cone in a certain target osculating plane is the center of the arc segment; for a straight line segment, since its curvature radius is infinite and the straight line leading edge must be obtained, the projection point of the vertex of the osculating cone in a certain target osculating plane is determined by the intersection of a specific straight line and the normal in the osculating plane. This specific straight line must pass through the center of the arc and ensure that the line connecting the projection point and the corresponding discrete point on the intake capture curve 2 has an intersection with the flow capture tube curve.

[0110] Among them, the osculating cone vertex of a target osculating plane is as follows Figure 7 As shown by point W in the figure, this point is the vertex of the osculating cone in the osculating plane where PHD is located. The position of this point can be determined by the length of the line segment PW, and the length of the line segment PW is determined by the shock wave angle and the length of the line segment PD. The calculation formula is as follows:

[0111]

[0112] In addition, the occluding cone vertices in other target occluding planes can be calculated using the same method.

[0113] Sub-step 1043, determine the leading edge point of the waverider of each target osculating plane by the intersection of the flow capture tube and the shock wave surface. The shock wave surface refers to the shock wave surface 3, which is a strong compression wave gathering area formed by the sharp decrease of flow velocity when the airflow passes through the leading edge of the waverider or a specific compression surface, such as Figure 7 shown.

[0114] Step 105, starting from the leading edge point of the waverider, streamline tracking is performed in the osculating cone flow field to the plane where the intake capture curve 2 is located; the lower surface of the waverider is composed of all streamlines associated with the osculating cone flow field, and a singular problem detection is performed on the lower surface of the waverider to update the lower surface of the waverider.

[0115] In this embodiment, two situations for generating the lower surface 1 of the waverider body can be selected according to specific design needs. After the intake capture curve 2 generates a discrete point set, as long as other parameters are kept unchanged, only part of the point set at the intersection of two straight line segments in the discrete point set is deleted. This can ensure that the two swept-back sections of the leading edge of the generated waverider body are still connected without transition.

[0116] Specifically, firstly, the lower surface 1 of the waverider is generated, and the specific singular problem (intersection or gap) of the surface is determined, and then corresponding processing is performed, and then the continuity of the function or function derivative at the intersection line is ensured according to specific needs.

[0117] 1) Intersection problem: First, all streamlines form the lower surface 1 of the waverider body. The planes formed by the streamlines obtained by the two swept sections are intersected. The redundant surfaces outside the intersection are deleted, and the remaining surfaces are retained to form the lower surface 1 of the waverider body. Then, the intersection is locally smoothed to ensure the continuity of the function or function derivative at the intersection according to specific needs.

[0118] 2) Gap problem: First, all streamlines form the lower surface 1 of the waverider body. The swept corresponding plane below the space is extended in the direction of another extended swept corresponding plane. The extended swept corresponding plane and the other extended swept corresponding plane are intersected to delete the redundant surfaces outside the intersection line, and the remaining surfaces are retained to form the lower surface 1 of the waverider body. Then, the intersection line is locally smoothed to ensure the continuity of the function or function derivative at the intersection line according to specific needs.

[0119] Step 106 , starting from the leading edge point of the waverider body, streamline tracing is performed in the free flow field to the plane where the intake capture curve 2 is located, and the upper surface of the waverider body is composed of all streamlines associated with the free flow field.

[0120] Step 107, at a preset flight altitude and a preset waverider fuselage length, the lift-to-drag ratio of the waverider is calculated using the reference temperature method through the inviscid flow field information provided by the osculating cone flow field, and the volumetric efficiency of the waverider is calculated in combination with the viscous force calculation method of the compression plate.

[0121] Among them, the volume efficiency The calculation is performed using the following formula:

[0122]

[0123] Where: represents the volume of the waverider, represents the plane area of ​​the waverider.

[0124] The waverider designed in the present invention can effectively utilize its swept-back effect to generate a stable separation vortex on the upper surface similar to a double delta wing. At the same time, the double swept-back leading edge expands the plane area of ​​the waverider, thereby increasing the lift of the waverider to a greater extent without reducing the volume efficiency. The designed swept-back angle is relatively small, similar to the effect of a double delta wing, and is more conducive to improving the low-speed performance of the waverider. The design without a transition section makes the leading edge of the entire waverider completely controllable in the design stage, which not only reduces the difficulty of engineering processing, but also significantly improves the structural stability of the waverider, improves the practical value of the overall structure, and has both engineering feasibility and application potential.

[0125] In order to verify the effect achieved by the design method of a double-swept osculating cone waverider with a curved head without a transition section provided by the present invention, the present invention also provides a corresponding simulation example, and the specific implementation method is as follows:

[0126] Under the design conditions of a flight altitude of 30 kilometers and a cruising Mach number of Mach 6, the fuselage length is set to 6 meters and the shape is selected to have the first sweep angle , the second sweep angle , the ratio of the length of the curved head fuselage to the length of the preset waverider fuselage , the ratio of the first swept section to the length of the preset waverider fuselage Combination of curve head and fuselage length , the fuselage length corresponding to the first sweep angle Under this condition, a waverider is generated and its waveriding characteristics are verified. The shock wave angle is determined based on the cruise Mach number and the sweep angle. arrive In this example, .

[0127] Then, the flow capture tube curve and the flow capture tube surface are determined, and then the intake capture curve 2 is determined.

[0128] The intake capture curve 2 is discretized to obtain discrete points, and a target osculating plane is generated from the discrete points. The osculating cone vertex is determined in each target osculating plane.

[0129] The Taylor-Maccoll equation is used to solve the conical flow field with an incoming flow Mach number of Mach 6 and a shock wave angle of 12.5°. The waverider leading edge curve is calculated, which consists of the intersection of the flow capture tube and the conical shock wave in each osculating plane.

[0130] In each osculating plane, taking the calculated point on the leading edge curve of the waverider as the starting point, streamline tracing is performed in the conical flow field and the free flow field respectively. The flow surface composed of the streamlines in the conical flow field is the lower surface of the waverider, and the singular problem of the lower surface is handled. The flow surface composed of the streamlines in the free flow field is the upper surface of the waverider.

[0131] Computational Fluid Dynamics (CFD) methods are used to verify the performance of the waverider, such as Figure 8 As shown in the figure, the waverider generated in this example has good waveriding characteristics. The lift-to-drag ratio of the waverider calculated using the CFD method is 5.3231. The lift-to-drag ratio of the surface waverider is relatively high and its aerodynamic efficiency is good.

[0132] See also Fig. 9 The present invention also provides a design system for a curved head double-swept osculating cone waverider without a transition section, the system comprising:

[0133] The shape parameter solving unit 201 is used to solve the shock angle and sweep angle parameters of the waverider based on a preset cruise Mach number, a preset waverider fuselage length and a preset curved head fuselage length;

[0134] A flow capture tube determination unit 202 is used to determine a flow capture tube curve and a flow capture tube surface according to the preset waverider fuselage length, the preset curved head fuselage length, the shock wave angle and the sweep angle parameters;

[0135] The air intake capture curve construction unit 203 is used to construct an air intake capture curve based on the shock wave angle, the sweep angle parameter, the preset curve head fuselage length, the flow capture tube curve and the flow capture tube surface; wherein the air intake capture curve is composed of a circular arc and two straight line segments connected in sequence;

[0136] A target osculating plane determining unit 204 is used to perform a discrete operation on the intake capture curve to obtain a plurality of target osculating planes, and solve the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane;

[0137] The waverider lower surface generating unit 205 is used to perform streamline tracking in the osculating cone flow field with the leading edge point of the waverider as the starting point, and track to the plane where the intake capture curve is located; the lower surface of the waverider is composed of all streamlines associated with the osculating cone flow field, and singular problem detection is performed on the lower surface of the waverider to update the lower surface of the waverider;

[0138] The upper surface generating unit 206 of the waverider is used to perform streamline tracing in the free flow field starting from the leading edge point of the waverider to the plane where the intake capture curve is located, and the upper surface of the waverider is composed of all streamlines associated with the free flow field.

[0139] The present invention also provides a computer device, comprising a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the above-mentioned design methods.

[0140] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned design methods are implemented.

[0141] The present invention also provides a computer program product, comprising a computer program, which implements the steps of any of the above-mentioned design methods when executed by a processor.

[0142] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0143] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0144] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0145] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0146] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0147] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A design method for a double-swept osculating cone waverider with a curved head without a transition section, characterized in that: The curved head of the waverider is formed by the intersection of two leading edges, each of which is composed of two straight line segments connected without a transition segment in the middle; the method comprises: Based on the preset cruise Mach number, the preset waverider fuselage length and the preset curved head fuselage length, the shock angle and the sweep angle parameters of the waverider are solved; Determining a flow capture tube curve and a flow capture tube curved surface according to the preset waverider body length, the preset curved head body length, the shock wave angle and the sweep angle parameters; Based on the shock wave angle, the sweep angle parameter, the preset curve head fuselage length, the flow capture tube curve and the flow capture tube surface, an intake capture curve is constructed; wherein the intake capture curve is composed of a circular arc and two straight line segments connected in sequence; Performing a discretization operation on the intake capture curve to obtain a plurality of target osculating planes, and solving the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane; Taking the leading edge point of the waverider as the starting point, streamline tracking is performed in the osculating cone flow field to the plane where the intake capture curve is located; the lower surface of the waverider is composed of all streamlines associated with the osculating cone flow field, and singular problem detection is performed on the lower surface of the waverider to update the lower surface of the waverider; Starting from the leading edge point of the waverider body, streamline tracing is performed in the free flow field to the plane where the intake capture curve is located, and the upper surface of the waverider body is composed of all streamlines associated with the free flow field.

2. The design method of the curved head double-swept osculating cone waverider according to claim 1 is characterized in that: Also includes: Under the preset flight altitude and preset waverider fuselage length, the lift-to-drag ratio of the waverider is calculated by the reference temperature method through the inviscid flow field information provided by the osculating cone flow field, and the volumetric efficiency of the waverider is calculated by combining the viscous force calculation method of the compressed plate.

3. The design method of the curved head double-swept osculating cone waverider according to claim 1 is characterized in that: The sweep angle parameter also includes a fuselage length corresponding to the first sweep angle; the step of determining a flow capture tube curve and a flow capture tube surface according to the preset waverider fuselage length, the shock wave angle and the sweep angle parameter includes: According to the preset waverider fuselage length, the shock wave angle, the first sweep angle, the second sweep angle and the fuselage length corresponding to the first sweep angle, the fuselage width corresponding to the curved head, the fuselage width corresponding to the first sweep angle and the fuselage width corresponding to the second sweep angle are calculated; The sum of the fuselage width corresponding to the head of the curve, the fuselage width corresponding to the first sweep angle and the fuselage width corresponding to the second sweep angle is taken as the length of the flow capture tube curve, and a horizontal straight line segment is used to construct the flow capture tube curve; The flow capture tube surface is determined from the flow capture tube curve.

4. The design method of the curved head double-swept osculating cone waverider according to claim 3 is characterized in that: The process of constructing the intake capture curve specifically includes: The arc is set on the side close to the symmetry plane of the waverider fuselage, and the parameters of the arc are calculated and determined by the preset waverider fuselage length, shock wave angle, first sweep angle and preset curve head fuselage length; two straight line segments are set on the side away from the symmetry plane of the waverider fuselage; wherein one end of the first straight line segment is connected to one end of the arc, and the first-order derivative continuity is ensured at the connection point; the other end of the first straight line segment is connected to one end of the second straight line segment; the other end of the second straight line segment is connected to one end of the flow capture tube curve away from the symmetry plane of the waverider fuselage, and the connection point forms a certain angle in the horizontal direction; Extend two straight line segments respectively, and discretize the circular arc and the two straight line segments into a series of discrete points, and use each discrete point as the normal line; use a series of planes that pass through the normal line and are perpendicular to the plane where the circular arc and the two straight line segments are located as multiple initial osculating planes; wherein the extension end points of the two straight line segments must meet the following conditions: the intersection of the initial osculating planes corresponding to the two straight line segments is located on the curved surface of the flow capture tube, and the osculating cone radii corresponding to the two straight line segments are equal in length; The lengths of the two straight line segments of the intake capture curve are calculated through the geometric constraint relationship between the extended end points of the two straight line segments and the flow capture tube curve and the initial osculating plane, thereby determining the intake capture curve.

5. The design method of the curved head double-swept osculating cone waverider according to claim 1 is characterized in that: The step of forming the lower surface of the waverider body by all streamlines associated with the osculating cone flow field, and performing singular problem detection on the lower surface of the waverider body to update the lower surface of the waverider body comprises: The lower surface of the waverider is composed of all streamlines associated with the osculating cone flow field; Performing singular problem judgment on the lower surface of the waverider to determine whether there is an intersection problem or a gap problem on the lower surface of the waverider; If the lower surface of the waverider body has an intersection problem, the planes formed by the streamlines corresponding to the two swept sections are intersected to delete the redundant surfaces other than the intersection line, and the remaining surfaces are retained to form the lower surface of the waverider body, and then the intersection line is locally smoothed to ensure the continuity of the function or function derivative at the intersection line according to the preset specific requirements; If there is a gap problem on the lower surface of the waverider body, the swept corresponding plane located below the space is extended in the direction of another extended swept corresponding plane, and the extended swept corresponding plane is intersected with the other extended swept corresponding plane to delete the redundant surfaces outside the intersection line, and the remaining surfaces are retained to form the lower surface of the waverider body, and then the intersection line is locally smoothed to ensure the continuity of the function or function derivative at the intersection line according to preset specific requirements.

6. The design method of the curved head double-swept osculating cone waverider according to claim 3 is characterized in that: The step of performing a discrete operation on the intake capture curve to obtain a plurality of target osculating planes, and solving the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane comprises: Discretize the air intake capture curve into a series of discrete points, and use a normal line through each discrete point; and use a series of planes that pass through the normal line and are perpendicular to the plane where the air intake capture curve is located as multiple target osculating planes; Determine the projection point of the occluding cone vertex in each target occluding plane, and determine the occluding cone vertex of each target occluding plane according to the shock wave angle, the corresponding discrete points on the intake capture curve and the projection point of the occluding cone vertex; solve and obtain the occluding cone flow field in each target occluding plane according to the preset cruise Mach number, the shock wave angle and the occluding cone vertex of each target occluding plane; The leading edge point of the waverider for each target osculating plane is determined by the intersection of the flow capture tube and the shock surface.

7. A design system for a double-swept osculating cone waverider with a curved head without a transition section, characterized in that: The system comprises: A shape parameter solving unit is used to solve the shock angle and sweep angle parameters of the waverider based on a preset cruise Mach number, a preset waverider fuselage length and a preset curved head fuselage length; A flow capture tube determination unit, used to determine a flow capture tube curve and a flow capture tube curved surface according to the preset waverider fuselage length, the preset curved head fuselage length, the shock wave angle and the sweep angle parameters; An air intake capture curve construction unit, used to construct an air intake capture curve based on the shock wave angle, the sweep angle parameter and the preset curve head fuselage length, the flow capture tube curve and the flow capture tube curved surface; wherein the air intake capture curve is composed of a circular arc and two straight line segments connected in sequence; a target osculating plane determining unit, configured to perform a discrete operation on the intake capture curve to obtain a plurality of target osculating planes, and to solve the osculating cone flow field and the leading edge point of the waverider body of each target osculating plane; The lower surface generating unit of the waverider is used for taking the leading edge point of the waverider as the starting point, performing streamline tracking in the osculating cone flow field, and tracking to the plane where the intake capture curve is located; forming the lower surface of the waverider from all streamlines associated with the osculating cone flow field, and performing singular problem detection on the lower surface of the waverider to update the lower surface of the waverider; The upper surface generating unit of the waverider is used to perform streamline tracing in the free flow field starting from the leading edge point of the waverider to the plane where the intake capture curve is located, and the upper surface of the waverider is composed of all streamlines associated with the free flow field.

8. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the design method according to any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the design method as described in any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the design method as described in any one of claims 1 to 6 are implemented.

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