Integrated Flow Control Method for Projectile Inlet to Improve Internal Space Utilization

Abstract

The present invention discloses an integrated flow control method for a projectile inlet to improve the utilization rate of the internal space, which includes the following steps: (1) Design a curved cone projectile and a three-dimensional inward-turning inlet; (2) Complete the design of the outer cover of the three-dimensional inward-turning inlet; (3) Intercept the symmetric meridian plane of the curved cone projectile / three-dimensional inward-turning inlet, and design the profile line of the array of bleed holes in the meridian plane; (4) Design the inlet of the bleed groove on the outer wall surface of the three-dimensional inward-turning inlet and generate the bleed groove structure to complete the design of the three-dimensional inward-turning inlet with adaptive lateral bleeding. The present invention follows the working principles and design methods of the curved cone projectile and the three-dimensional inward-turning inlet. In addition to ensuring the aerodynamic characteristics of the curved cone projectile and the three-dimensional inward-turning inlet itself, it can significantly broaden the working speed range of the three-dimensional inward-turning inlet, improve the internal flow field quality of the three-dimensional inward-turning inlet, reduce the occupation of the internal space of the curved cone projectile by the bleed channel, and help improve the utilization rate of the internal space of the curved cone projectile.

Description

Technical Field

[0001] This patent relates to the technical fields of curved cone projectiles, three-dimensional internal turning inlet ducts, and hypersonic flow control. Specifically, it relates to a method for integrated flow control of a projectile inlet duct that improves the internal space utilization rate. While improving the operating speed range of the integrated configuration, it reduces the occupation of the internal space of the curved cone projectile by the bleed channel and enhances the internal space utilization rate of the curved cone projectile. Background Art

[0002] The integrated design method of the curved cone projectile mainly adopts the submandibular distribution. The hypersonic inlet duct is a key component of a scramjet engine. Only when the inlet duct captures enough air and compresses it efficiently can the engine generate enough thrust to propel the aircraft for hypersonic flight. The three-dimensional internal turning inlet duct is widely used in hypersonic aircraft due to its excellent compression performance and flow capture ability. The three-dimensional internal turning inlet duct applied in the propulsion system of hypersonic aircraft mainly provides a sufficient amount of highly compressed air flow for the combustion chamber and ensures the normal operation of the hypersonic propulsion system. Due to the characteristics of gas viscosity, there are a large number of low-speed airflows on the surface of the curved cone projectile and at the inlet of the hypersonic inlet duct, forming a boundary layer. The existence of the boundary layer reduces the flow capture area at the inlet of the inlet duct, thereby reducing the capture ability of the inlet duct for hypersonic airflows. In addition, the shock wave / boundary layer interference will cause significant changes in the shock wave system in the internal flow field region of the inlet duct, resulting in a large amount of energy loss, causing the flow to separate on the wall; in severe cases, it may also lead to the thickening of the airflow boundary layer in the inlet duct, "choking" at the throat, and even cause the inlet duct to unstart, affecting the normal operation of the entire propulsion system.

[0003] Boundary layer flow control is the main research field in the application of fluid technology. With the development of the understanding level and engineering technology, in order to broaden the working range of the three-dimensional internal turning inlet duct, domestic and foreign scholars have proposed a series of design methods to improve the starting performance of the integrated configuration, mainly focusing on the improved design of the three-dimensional internal turning inlet duct. Fukuda M, Mitani T, etc. believed through experiments that the position before the incident shock wave and after the isolation section of the three-dimensional internal turning inlet duct is the optimal design point position of the bleed slot; Chyu W found that when the bleed direction is perpendicular to the airflow direction in the inlet duct, it can better separate the wall flow. The method of achieving flow control by bleeding through the three-dimensional internal turning inlet duct realizes the displacement of the low-energy flow in the inlet duct and reduces the starting Mach number of the three-dimensional internal turning inlet duct. By setting appropriate bleed holes in the supersonic inlet duct, adverse shock wave / boundary layer interference can be avoided and the performance of the inlet duct can be improved. The bleed flow control method has been widely applied to hypersonic aircraft and has become one of the key technologies of hypersonic aircraft.

[0004] In the conventional flow discharge method, the flow discharge channel is vertically upward. The integrated design of the lower jaw type curved cone projectile and the three-dimensional internal turning inlet will cause the flow discharge channel to excessively occupy the internal space of the projectile, resulting in a reduction in the utilization rate of the internal space of the projectile. For hypersonic missiles, a reduction in the utilization rate of the internal space of the projectile is equivalent to a decline in the fuel reserve performance of the projectile, which to a certain extent restricts the flight mission of hypersonic missiles. This patent takes changing the flow discharge direction of the inlet as a breakthrough point and reasonably designs the flow discharge inlet. Its aim is to provide an internal and external flow integrated design method for the curved cone projectile three-dimensional internal turning inlet with high space utilization rate and excellent starting performance. It adopts an array of flow discharge holes as the flow discharge method of the flow discharge inlet. While ensuring the normal displacement of the low-speed airflow in the three-dimensional internal turning inlet, it realizes the boundary layer control in the inlet by the flow discharge method of the flow discharge holes, and prevents the interaction between the shock wave train in the inlet and the low-speed airflow in the flow discharge holes, reduces the turbulence degree of the internal flow field of the three-dimensional internal turning inlet, and improves the quality of the internal flow field of the three-dimensional internal turning inlet. In addition, by changing the flow discharge direction, the occupation of the internal space of the forebody by the flow discharge groove can be reduced, which is beneficial to improving the utilization rate of the internal space of the forebody. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, this patent aims to provide an integrated flow control method for the projectile inlet to improve the utilization rate of the internal space. While maintaining the advantages of the three-dimensional internal turning inlet, it adopts the lateral flow discharge method to realize the displacement of the boundary layer in the inlet. While broadening the working Mach number range of the three-dimensional internal turning inlet, it reduces the occupation of the internal space of the airframe by the flow discharge groove and avoids the interference of the low-speed airflow displaced in the three-dimensional internal turning inlet to the inside of the airframe.

[0006] The present invention is realized through the following technical solutions.

[0007] A method for integrated flow control of a projectile inlet to improve the utilization rate of internal space, the structure of which includes a curved cone projectile, a three-dimensional inward-turning inlet shroud, an isentropic compression profile of the three-dimensional inward-turning inlet, a three-dimensional inward-turning inlet isolation section, an array of bleed holes and a bleed slot device. Each component of the three-dimensional inward-turning inlet is a geometric profile with a certain thickness. In addition, the wall thickness does not cause improper limitation to the functions of the present invention, etc. This patent only shows the key parts of the inner surface and the outer surface of the three-dimensional inward-turning inlet to more clearly understand the design method and functions of this patent. The curved cone projectile is a surface obtained by rotating a multi-curve as the generatrix of the curved cone projectile around the central axis of the cone; the three-dimensional inward-turning inlet includes an isentropic compression profile of the three-dimensional inward-turning inlet and a three-dimensional inward-turning inlet isolation section, and the isentropic compression profile of the three-dimensional inward-turning inlet and the three-dimensional inward-turning inlet isolation section are connected by a shoulder profile of the three-dimensional inward-turning inlet; the three-dimensional inward-turning inlet shroud is connected to the curved cone projectile through a connection line of the three-dimensional inward-turning inlet shroud, and the three-dimensional inward-turning inlet shroud places the three-dimensional inward-turning inlet between the three-dimensional inward-turning inlet shroud and the curved cone projectile to realize the integrated design of the curved cone projectile and the three-dimensional inward-turning inlet.

[0008] The array of bleed holes and the bleed slot part include a bleed hole inlet of the array, bleed holes of the array, a bleed hole outlet of the array, a bleed slot and a bleed slot outlet. Select the symmetric meridian plane of the curved cone projectile and the three-dimensional inward-turning inlet, and design a meridian plane array bleed hole profile downstream of the intersection line of the isentropic compression profile in the symmetric meridian plane, which is an array of circles with equal radii and equal center distances. The projected area of the array of circles on the meridian plane of the isentropic compression profile of the three-dimensional inward-turning inlet is higher than 2% to achieve the effect of displacing the low-speed air flow in the inlet. The projected profile of the array of circles along the two directions perpendicular to the meridian plane on the inner surface of the isentropic compression profile of the three-dimensional inward-turning inlet is the bleed hole inlet of the array; the bleed holes of the array continue to extend along the stretching direction to the outer surface of the isentropic compression profile of the three-dimensional inward-turning inlet to form an array of pore structures; this pore structure is the bleed holes of the array, and the intersection line of the bleed holes of the array and the outer surface of the isentropic compression profile of the three-dimensional inward-turning inlet is the bleed hole outlet of the array. On the outer edge of the bleed hole outlets on both sides, a closed curved quadrilateral is designed on the outer surface of the isentropic compression profile of the three-dimensional inward-turning inlet, and this curved quadrilateral is stretched along the extending direction of the bleed holes of the array to intersect with the three-dimensional inward-turning inlet shroud, and the formed intersection line is the bleed slot outlet part. The bleed slot sizes on both sides of the meridian plane are the same to ensure the symmetry of the entire device.

[0009] During the isentropic compression process of hypersonic airflow at the isentropic compression surface of a three-dimensional internal compression inlet, a large amount of high-pressure and low-speed airflow will be generated, and part of it will adhere to the inner wall surface of the three-dimensional internal compression inlet, forming a boundary layer. The generation of the boundary layer will occupy the throat space of the three-dimensional internal compression inlet, inhibit the flow of hypersonic airflow, and easily cause blockage of the three-dimensional internal compression inlet in severe cases. The design of the array of bleed holes and bleed slots is based on the static pressure difference between the inside and outside of the inlet. By utilizing the pressure difference distribution, the low-speed airflow inside the three-dimensional internal compression inlet can be displaced to the outside, thereby reducing the content of low-speed airflow inside the three-dimensional internal compression inlet, decreasing the boundary layer thickness at the isentropic compression surface wall of the three-dimensional internal compression inlet, and broadening the working Mach number range of the three-dimensional internal compression inlet. By adopting the method of lateral bleeding through the array of bleed holes, the mutual interference between the shock wave and the low-energy flow at the bleed inlet can be weakened while ensuring the normal displacement of the low-speed airflow inside the three-dimensional internal compression inlet, reducing the turbulence degree of the internal flow field of the three-dimensional internal compression inlet; in addition, the quality of the internal flow field of the three-dimensional internal compression inlet is improved, the utilization rate of the internal space of the curved surface cone projectile is increased, and when realizing the integrated layout of the airframe / inlet under the chin type, the internal space of the airframe is increased.

[0010] A method for integrated flow control of a projectile inlet to improve the utilization rate of internal space, comprising the following steps:

[0011] (1). Design a curved surface cone projectile and a three-dimensional internal compression inlet;

[0012] (2). According to the curved surface cone projectile and the three-dimensional internal compression inlet designed in step (1), complete the design of the outer cover of the three-dimensional internal compression inlet;

[0013] (3). Intercept the symmetric meridian plane of the curved surface cone projectile / three-dimensional internal compression inlet, and design the profile line of the array of bleed holes in the meridian plane;

[0014] (4). According to the meridian plane array of bleed hole profile lines obtained in step (3), design the bleed slot inlet on the outer wall surface of the three-dimensional internal compression inlet and generate the bleed slot structure to complete the design of the three-dimensional internal compression inlet with adaptive lateral bleeding.

[0015] In the above step (1), the curved surface cone projectile is obtained by rotating the generatrix of the curved surface cone projectile 360° around the axis of the projectile; the generatrix of the curved surface cone projectile is a multi-curve spline with a gradually decreasing slope; according to the external shape characteristics of the curved surface cone projectile, a three-dimensional internal contraction basic flow field is designed at the chin of the curved surface cone projectile, and the isentropic compression surface of the three-dimensional internal compression inlet is obtained by using the streamline tracking technology in the three-dimensional internal contraction basic flow field. The tail end of the isentropic compression surface of the three-dimensional internal compression inlet is stretched in the flow direction to obtain a pipe system structure, and the isolation section of the three-dimensional internal compression inlet is obtained by the method of geometric modification. The wall surface of this three-dimensional internal compression inlet is a geometric body with a certain thickness, and only the key parts of the inner surface and the outer surface of the three-dimensional internal compression inlet are shown in the figure.

[0016] In the step (2), the outer cover of the three-dimensional inward-turning inlet is obtained by stretching the inlet profile of the three-dimensional inward-turning inlet along the hypersonic airflow compression direction; the hypersonic airflow compression direction is based on between the stretching direction of the isolator and the slope direction of the curved conical projectile abdomen, so that the three-dimensional inward-turning inlet is integrally arranged inside the outer cover of the three-dimensional inward-turning inlet; the outer cover of the three-dimensional inward-turning inlet is connected to the curved conical projectile through the connecting line of the outer cover of the three-dimensional inward-turning inlet, forming a closed body with the curved conical projectile.

[0017] In the step (3), before selecting the shoulder profile of the three-dimensional inward-turning inlet, the high-pressure area of the airflow after the inlet profile of the three-dimensional inward-turning inlet is used as the design point for the inlet of the array bleed holes of the three-dimensional inward-turning inlet. This design position is located in the upper and middle part of the isentropic compression profile of the three-dimensional inward-turning inlet near the shoulder profile; the design principle adopted is to utilize the distribution characteristics of the large pressure difference between the isentropic compression zone of the three-dimensional inner contraction basic flow field and the external airflow, which helps to realize the displacement of the low-energy flow inside the three-dimensional inward-turning inlet; in addition, research shows that: the accumulation of low-energy flow is the most serious at this position, and the displacement benefit of the low-energy flow inside the inlet can be maximized by adopting the bleed method at this position. The symmetric meridian plane of the curved conical projectile / three-dimensional inward-turning inlet integrated structure is intercepted, and the meridian plane array bleed hole profile is designed in the plane. The meridian plane array bleed hole profile is composed of several array circles with equal radii, and the center distances between the array circles in the same direction are equal; the size of the meridian plane array bleed hole profile depends on the projected area of the isentropic compression profile of the three-dimensional inward-turning inlet on the meridian plane, ensuring that the ratio of the size of a single meridian plane array bleed hole profile to the projected area of the isentropic compression profile of the three-dimensional inward-turning inlet on the meridian plane is higher than 2%. The position of the meridian plane array bleed hole profile is located upstream of the isentropic compression zone of the three-dimensional inner contraction basic flow field and near the shoulder profile of the three-dimensional inward-turning inlet, ensuring that the meridian plane array bleed hole profile can be completely projected onto the inner surface of the isentropic compression profile of the three-dimensional inward-turning inlet along the direction perpendicular to the meridian plane.

[0018] In the said step (4), by projecting the meridional plane array bleed hole profile obtained in step (3) onto the inner surface of the isentropic compression profile of the three-dimensional inward-turning intake duct in a direction perpendicular to the meridional plane, the obtained projection curve is the inlet of the array bleed hole; the inlet of the array bleed hole is stretched on both sides in a direction perpendicular to the meridional plane, and the geometric body overlapping with the wall surface of the three-dimensional inward-turning intake duct is subtracted to obtain the structure of the array bleed hole; the stretching direction of the array bleed hole is the same as the direction of the central axis of the array circle, and the stretching distance is equal to the wall thickness of the isentropic compression profile of the three-dimensional inward-turning intake duct. Taking the bleed hole on the inner surface of the isentropic compression profile of the three-dimensional inward-turning intake duct as the starting stage of stretching, it is the inlet of the array bleed hole; taking the outer surface of the three-dimensional inward-turning intake duct as the ending stage of stretching, it is the outlet of the array bleed hole; the internal space of stretching is the array bleed hole of the three-dimensional inward-turning intake duct. The positions and lengths of the array bleed holes corresponding to both sides of the isentropic compression profile of the three-dimensional inward-turning intake duct are equal to ensure the symmetry of the structure of the three-dimensional inward-turning intake duct. A bleed slot inlet profile is designed for the peripheral part of the array bleed hole outlet, and its geometric shape is a curved quadrilateral. The bleed slot inlet profile is located on the outer surface of the three-dimensional inward-turning intake duct, at the leading edge part of the shoulder profile of the three-dimensional inward-turning intake duct, behind the isentropic compression profile of the three-dimensional inward-turning intake duct, and this curved quadrilateral completely surrounds all the array bleed hole outlets; the bleed slot is obtained by stretching the bleed slot inlet profile along the extension direction of the array bleed hole inlet; the bleed slot is bounded by the bleed slot inlet profile and the bleed slot outlet profile, and the bleed slot outlet profile is the intersection line of the bleed slot and the outer cover of the three-dimensional inward-turning intake duct; the positions and sizes of the bleed slots on both sides of the isentropic compression profile of the three-dimensional inward-turning intake duct are the same to ensure the symmetry of the structure of the three-dimensional inward-turning intake duct. The low-speed air flow displaced by the intake duct flows out to the bleed slot through the array bleed hole outlet and is displaced to the outside through the bleed slot outlet. The boundary layer mainly accumulates in the upper and middle reaches of the isentropic compression profile of the three-dimensional inward-turning intake duct, near the shoulder profile of the three-dimensional inward-turning intake duct. Designing the array bleed hole at this position is more conducive to the displacement of the boundary layer and can maximize the displacement benefit of the low-energy flow. Adopting the layout method of lateral bleeding at the inlet of the array bleed hole is beneficial to avoiding the shock wave in the flow field hitting the inner wall surface of the bleed hole and interfering with the displaced low-speed air flow, resulting in more complex flow. The three-dimensional inward-turning intake duct is usually integrated with the airframe in a submandibular layout. Adopting the design method of lateral array bleed holes completely avoids the bleed slot structure extending into the airframe internal space and occupying part of the airframe internal space. To a certain extent, it reduces the occupancy rate of the bleed slot in the internal space of the curved cone projectile and improves the airframe internal space.

[0019] Compared with the prior art, the advantages of the present invention are as follows: An adaptive lateral bleeding three-dimensional internal turning inlet generated by using the present design method can first mainly broaden the working range of the three-dimensional internal turning inlet; through the pressure difference between the inside and outside of the three-dimensional internal turning inlet, the high-pressure and low-speed air flow at the isentropic compression profile of the three-dimensional internal turning inlet is discharged to the outside along the bleeding holes and bleeding grooves, so as to achieve the boundary layer control in the isentropic compression zone of the three-dimensional internal contraction basic flow field. The method of lateral bleeding can weaken the mutual interference between the shock wave in the inlet and the high-pressure and low-speed air flow in the bleeding groove, avoid the complexity of the internal flow field in the three-dimensional internal turning inlet, and suppress the flow separation in the three-dimensional internal turning inlet; in addition, by using the method of lateral bleeding with an array of bleeding holes, the starting performance of the three-dimensional internal turning inlet can be greatly improved with a small flow loss, and the flow field quality in the high-pressure area after the reflected shock wave of the three-dimensional internal contraction basic flow field can be improved, ensuring the thrust requirement of the entire three-dimensional internal turning inlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain and illustrate the invention and do not constitute an improper limitation to the present invention.

[0021] Figure 1 It is a schematic diagram of a curved surface cone projectile;

[0022] Figure 2 It is a schematic diagram of designing a three-dimensional internal contraction basic flow field;

[0023] Figure 3 It is a schematic diagram of streamline tracing of a three-dimensional internal contraction basic flow field;

[0024] Figure 4 It is a generated diagram of a three-dimensional internal turning inlet;

[0025] Figure 5 It is a schematic diagram of the integrated structure of a curved surface cone projectile / three-dimensional internal turning inlet;

[0026] Figure 6 It is a schematic diagram of the integrated working principle of a curved surface cone projectile / three-dimensional internal turning inlet;

[0027] Figure 7 It is a schematic diagram of the meridian plane of the integrated structure of a curved surface cone projectile / three-dimensional internal turning inlet;

[0028] Figure 8 It is a sectional view of the integrated structure of an adaptive lateral bleeding three-dimensional internal turning inlet for improving the internal space of the fuselage;

[0029] Figure 9 It is the front view of the overall structure of a lateral bleeding three-dimensional internal turning inlet and its outer cover;

[0030] Figure 10It is the top view of the overall structure of the three-dimensional inward-turning inlet with lateral bleeding and its outer cover;

[0031] Figure 11 It is the schematic diagram of the working principle of the three-dimensional inward-turning inlet with lateral bleeding;

[0032] Figure 12 It is the schematic diagram of the overall structure of the three-dimensional inward-turning inlet with lateral bleeding;

[0033] Figure 13 It is the schematic diagram of the overall appearance of an adaptive three-dimensional inward-turning inlet with lateral bleeding for enhancing the internal space of the airframe;

[0034] Figure 14 It is the front view of the overall appearance of an adaptive three-dimensional inward-turning inlet with lateral bleeding for enhancing the internal space of the airframe;

[0035] Annotation of the attached figure: 1 represents the curved cone projectile, 2 represents the central rotation axis of the cone, 3 represents the generatrix of the curved cone projectile, 4 represents the uniform area of the incident shock wave front in the three-dimensional internal contraction basic flow field, 5 represents the incident shock wave in the three-dimensional internal contraction basic flow field, 6 represents the reflected shock wave in the three-dimensional internal contraction basic flow field, 7 represents the high-pressure area behind the reflected shock wave in the three-dimensional internal contraction basic flow field, 8 represents the axis of rotation in the three-dimensional internal contraction basic flow field, 9 represents the hypersonic airflow, 10 represents the isentropic compression area in the three-dimensional internal contraction basic flow field, 11 represents the generatrix of rotation in the three-dimensional internal contraction basic flow field, 12 represents the streamline for generating the three-dimensional inward-turning inlet, 13 represents the isentropic compression profile of the three-dimensional inward-turning inlet, 14 represents the inlet profile of the three-dimensional inward-turning inlet, 15 represents the shoulder profile of the three-dimensional inward-turning inlet, 16 represents the isolation section of the three-dimensional inward-turning inlet, 17 represents the outlet profile of the isolation section of the three-dimensional inward-turning inlet, 18 represents the outer cover of the three-dimensional inward-turning inlet, 19 represents the connection line of the outer cover of the three-dimensional inward-turning inlet, 20 represents the boundary layer, 21 represents the hypersonic compressed airflow, 22 represents the meridian intersection line of the curved cone projectile, 23 represents the meridian intersection line of the isentropic compression profile of the three-dimensional inward-turning inlet, 24 represents the profile of the meridian array bleeding holes, 25 represents the meridian intersection line of the outer cover of the three-dimensional inward-turning inlet, 26 represents the meridian intersection line of the isolation section of the three-dimensional inward-turning inlet, 27 represents the inlet of the array bleeding holes, 28 represents the outlet profile of the bleeding groove, 29 represents the bleeding groove, 30 represents the outer surface of the three-dimensional inward-turning inlet, 31 represents the array bleeding holes, 32 represents the inlet profile of the bleeding groove, 33 represents the outlet of the array bleeding holes. Specific implementation manners

[0036] The following will detail the implementation manners of the present invention in conjunction with the attached drawings and embodiments, so as to fully understand how the present invention applies technical means to solve technical problems and achieve the realization process of technical effects and implement accordingly. However, it is not a limitation of the present invention.

[0037] As Figures 1 to 14 shown:

[0038] In the described step (1), the curved surface cone projectile 1 is obtained by rotating the generatrix 3 of the curved surface cone projectile 360° around the axis of the projectile; the generatrix 3 of the curved surface cone projectile is a multi-curve spline with a gradually decreasing slope; according to the external shape characteristics of the curved surface cone projectile 1, a three-dimensional internal contraction basic flow field is designed at the lower jaw of the curved surface cone projectile 1, and an isentropic compression profile 13 of the three-dimensional internal turning inlet is obtained by using the streamline tracing technology in the three-dimensional internal contraction basic flow field. The tail end of the isentropic compression profile 13 of the three-dimensional internal turning inlet is stretched in the flow direction to obtain a pipe system structure, and the isolation section 16 of the three-dimensional internal turning inlet is obtained by means of geometric modification. The wall surface of the three-dimensional internal turning inlet is a geometric body with a certain thickness, and only the key parts of the inner surface and the outer surface 30 of the three-dimensional internal turning inlet are shown in the figure.

[0039] In the described step (2), the outer cover 18 of the three-dimensional internal turning inlet is obtained by stretching the inlet profile 14 of the three-dimensional internal turning inlet along the compression direction of the hypersonic compression air flow 21; the compression direction of the hypersonic compression air flow 21 is between the stretching direction of the isolation section and the slope direction of the abdomen of the curved surface cone projectile 1, so that the three-dimensional internal turning inlet is integrally arranged inside the outer cover 18 of the three-dimensional internal turning inlet; the outer cover 18 of the three-dimensional internal turning inlet is connected to the curved surface cone projectile 1 through the connecting line 19 of the outer cover of the three-dimensional internal turning inlet, forming a closed closed shape with the curved surface cone projectile 1.

[0040] In the described step (3), before selecting the shoulder profile 15 of the three-dimensional internal turning inlet, the high-pressure area of the air flow after the inlet profile 14 of the three-dimensional internal turning inlet is used as the design point of the inlet 27 of the three-dimensional internal turning inlet array bleed hole, and the design position is in the upper and middle part of the isentropic compression profile 13 of the three-dimensional internal turning inlet near the shoulder profile; the design principle adopted is to utilize the distribution characteristics of the large pressure difference between the isentropic compression zone of the three-dimensional internal contraction basic flow field and the external air flow, which helps to realize the displacement of the low-energy flow inside the three-dimensional internal turning inlet; in addition, research shows that the low-energy flow accumulates most seriously at this position, and the displacement benefit of the low-energy flow inside the inlet can be maximized by adopting the bleed method at this position. The symmetric meridian plane of the integrated structure of the curved surface cone projectile 1 / three-dimensional internal turning inlet is intercepted, and the meridian plane array bleed hole profile 24 is designed in the plane. The meridian plane array bleed hole profile 24 is a number of array circles with equal radii, and the center distance between the array circles in the same direction is equal; the size of the meridian plane array bleed hole profile 24 depends on the projected area of the isentropic compression profile 13 of the three-dimensional internal turning inlet on the meridian plane, ensuring that the ratio of the size of a single meridian plane array bleed hole profile 24 to the projected area of the isentropic compression profile 13 of the three-dimensional internal turning inlet on the meridian plane is higher than 2%. The position of the meridian plane array bleed hole profile 24 is upstream of the isentropic compression zone of the three-dimensional internal contraction basic flow field and near the shoulder profile 15 of the three-dimensional internal turning inlet, ensuring that the meridian plane array bleed hole profile 24 can be completely projected onto the inner surface of the isentropic compression profile of the three-dimensional internal turning inlet along the direction perpendicular to the meridian plane.

[0041] In step (4), the projected curve obtained by projecting the meridional plane array bleed hole profile line 24 obtained in step (3) onto the inner surface of the isentropic compression profile of the three-dimensional inward-turning intake passage in a direction perpendicular to the meridional plane is the inlet 27 of the array bleed hole; the inlet 27 of the array bleed hole is stretched on both sides in a direction perpendicular to the meridional plane, and the overlapping part of the geometry with the wall surface of the three-dimensional inward-turning intake passage is subtracted to obtain the structure of the array bleed hole 31; the stretching direction of the array bleed hole 31 is the same as the direction of the central axis of the array circle, and the stretching distance is equal to the wall thickness of the isentropic compression profile 13 of the three-dimensional inward-turning intake passage. Taking the bleed hole on the inner surface of the isentropic compression profile of the three-dimensional inward-turning intake passage as the starting stage of stretching, it is the inlet 27 of the array bleed hole; taking the outer surface 30 of the three-dimensional inward-turning intake passage as the ending stage of stretching, it is the outlet 33 of the array bleed hole; the internal space of stretching is the array bleed hole 31 of the three-dimensional inward-turning intake passage, and the positions and lengths of the array bleed holes 31 corresponding to both sides of the isentropic compression profile 13 of the three-dimensional inward-turning intake passage are equal to ensure the symmetry of the structure of the three-dimensional inward-turning intake passage. A bleed slot inlet profile line 32 is designed for the peripheral part of the array bleed hole outlet 33, and its geometric shape is a curved quadrilateral. The bleed slot inlet profile line 32 is located on the outer surface 30 of the three-dimensional inward-turning intake passage, at the leading edge part of the shoulder profile line 15 of the three-dimensional inward-turning intake passage, behind the isentropic compression profile 13 of the three-dimensional inward-turning intake passage, and this curved quadrilateral completely encloses all the array bleed hole outlets 33; the bleed slot 29 is obtained by stretching the bleed slot inlet profile line 32 in the extending direction of the array bleed hole inlet 27; the bleed slot 29 is bounded by the bleed slot inlet profile line 32 and the bleed slot outlet profile line 28, and the bleed slot outlet profile line 28 is the intersection line of the bleed slot 29 and the outer cover 18 of the three-dimensional inward-turning intake passage; the positions and sizes of the bleed slots 29 on both sides of the isentropic compression profile 13 of the three-dimensional inward-turning intake passage are the same to ensure the symmetry of the structure of the three-dimensional inward-turning intake passage. The low-speed air flow displaced by the intake passage flows out to the bleed slot 29 through the array bleed hole outlet 33 and is displaced to the outside from the outlet of the bleed slot 29. The boundary layer 20 mainly accumulates in the upper and middle reaches of the isentropic compression profile 13 of the three-dimensional inward-turning intake passage, near the shoulder profile line 15 of the three-dimensional inward-turning intake passage. Designing the array bleed hole 31 at this position is more conducive to the displacement of the boundary layer 20 and can maximize the displacement benefit of the low-energy flow. Adopting the layout method of lateral bleeding at the inlet 27 of the array bleed hole is beneficial to avoiding the shock wave in the flow field hitting the inner wall surface of the bleed hole and interfering with the displaced low-speed air flow, resulting in more complex flow. The three-dimensional inward-turning intake passage is usually integrated with the airframe in a submandibular layout. Adopting the design method of the lateral array bleed hole 31 completely avoids the extension of the bleed slot 29 structure into the airframe internal space and occupies part of the airframe internal space. To a certain extent, it reduces the occupancy rate of the bleed slot 29 in the internal space of the curved cone projectile 1 and improves the airframe internal space.

[0042] Compared with the prior art, the advantages of the present invention are as follows: An adaptive laterally bleeding three-dimensional inward-turning inlet generated by using the present design method can primarily broaden the working range of the three-dimensional inward-turning inlet; through the pressure difference inside and outside the three-dimensional inward-turning inlet, the high-pressure and low-speed airflow at the isentropic compression profile of the three-dimensional inward-turning inlet is displaced to the outside along the bleeding holes and bleeding grooves, thereby realizing the boundary layer flow control in the isentropic compression zone of the three-dimensional internal contraction basic flow field. The method of lateral bleeding can weaken the mutual interference between the shock wave in the inlet and the high-pressure and low-speed airflow in the bleeding groove, avoid the complexity of the internal flow field in the three-dimensional inward-turning inlet, and suppress the flow separation in the three-dimensional inward-turning inlet; in addition, by using the method of lateral bleeding with array bleeding holes, the starting performance of the three-dimensional inward-turning inlet can be greatly improved with a small flow loss, and the flow field quality in the high-pressure area after the reflected shock wave of the three-dimensional internal contraction basic flow field is improved, ensuring the thrust requirement of the entire three-dimensional inward-turning inlet. The beneficial effects of the present invention are as follows: An adaptive laterally bleeding three-dimensional inward-turning inlet generated by using the present design method can primarily broaden the working range of the three-dimensional inward-turning inlet; through the pressure difference inside and outside the three-dimensional inward-turning inlet, the high-pressure and low-speed airflow at the isentropic compression profile of the three-dimensional inward-turning inlet is displaced to the outside along the bleeding holes and bleeding grooves, thereby realizing the boundary layer control in the isentropic compression zone of the three-dimensional internal contraction basic flow field. The method of lateral bleeding can weaken the mutual interference between the shock wave in the inlet and the high-pressure and low-speed airflow in the bleeding groove, avoid the complexity of the internal flow field in the three-dimensional inward-turning inlet, and suppress the flow separation in the three-dimensional inward-turning inlet; in addition, by using the method of lateral bleeding with array bleeding holes, the starting performance of the three-dimensional inward-turning inlet can be greatly improved with a small flow loss, and the flow field quality in the high-pressure area after the reflected shock wave of the three-dimensional internal contraction basic flow field is improved, ensuring the aerodynamic performance of the entire three-dimensional inward-turning inlet.

[0043] The above is only an illustration of the best embodiment of the present invention, but it should not be construed as a limitation to the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to vary. All changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

[0044] The above description is only a preferred embodiment of the present invention, and does not therefore limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be able to realize that all equivalent substitutions and obvious changes made by using the description and illustration content of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated flow control method for a projectile inlet that improves the utilization rate of internal space, characterized in that It includes the following steps: (1) Design a curved surface cone projectile and a three-dimensional internal turning inlet; the curved surface cone projectile is obtained by rotating the generatrix of the curved surface cone projectile 360° around the axis of the projectile; the generatrix of the curved surface cone projectile is a multi-curve spline with a gradually decreasing slope; according to the shape characteristics of the curved surface cone projectile, design a three-dimensional internal contraction basic flow field at the lower jaw of the curved surface cone projectile, and obtain the isentropic compression profile of the three-dimensional internal turning inlet by using the streamline tracing technique in the three-dimensional internal contraction basic flow field; The tail end of the isentropic compression profile of the three-dimensional internal turning inlet is stretched along the flow direction to obtain a pipe system structure, and the isolation section of the three-dimensional internal turning inlet is obtained by means of geometric modification; (2) According to the curved surface cone projectile and the three-dimensional internal turning inlet designed in step (1), complete the design of the outer cover of the three-dimensional internal turning inlet; the outer cover of the three-dimensional internal turning inlet is obtained by stretching the inlet profile of the three-dimensional internal turning inlet along the direction of hypersonic airflow compression; the direction of hypersonic airflow compression is based on the stretching direction of the isolation section and the slope direction of the abdomen of the curved surface cone projectile, so that the three-dimensional internal turning inlet is integrally arranged inside the outer cover of the three-dimensional internal turning inlet; the outer cover of the three-dimensional internal turning inlet is connected to the curved surface cone projectile through the connecting line of the outer cover of the three-dimensional internal turning inlet, and forms a closed and sealed body with the curved surface cone projectile; (3) Intercept the symmetric meridian plane of the curved surface cone projectile / three-dimensional internal turning inlet, and design the profile of the array of bleed holes in the meridian plane; select the high-pressure area of the airflow before the shoulder profile of the three-dimensional internal turning inlet and after the inlet profile of the three-dimensional internal turning inlet as the design point of the inlet of the array of bleed holes of the three-dimensional internal turning inlet, and the design position is in the upper and middle part of the isentropic compression profile of the three-dimensional internal turning inlet near the shoulder profile; the design principle adopted is to utilize the distribution characteristics of the large pressure difference between the isentropic compression zone of the three-dimensional internal contraction basic flow field and the external airflow, which helps to realize the displacement of the low-energy flow inside the three-dimensional internal turning inlet; intercept the symmetric meridian plane of the integrated structure of the curved surface cone projectile / three-dimensional internal turning inlet, and design the profile of the meridian plane array of bleed holes in the meridian plane; the profile of the meridian plane array of bleed holes is a number of array circles with equal radii, and the center distances between the array circles in the same direction are equal; the size of the profile of the meridian plane array of bleed holes depends on the projected area of the isentropic compression profile of the three-dimensional internal turning inlet on the meridian plane, and ensure that the ratio of the size of a single profile of the meridian plane array of bleed holes to the projected area of the isentropic compression profile of the three-dimensional internal turning inlet on the meridian plane is higher than 2%; the position of the profile of the meridian plane array of bleed holes is upstream of the isentropic compression zone of the three-dimensional internal contraction basic flow field and near the shoulder profile of the three-dimensional internal turning inlet, and ensure that the profile of the meridian plane array of bleed holes can be completely projected onto the inner surface of the isentropic compression profile of the three-dimensional internal turning inlet along the direction perpendicular to the meridian plane; (4) Based on the meridian plane array bleed hole profile obtained in step (3), design the bleed slot inlet on the outer wall surface of the three-dimensional inward-turning intake duct and generate the bleed slot structure to complete the design of the three-dimensional inward-turning intake duct with adaptive lateral bleeding; by projecting the meridian plane array bleed hole profile obtained in step (3) onto the inner surface of the isentropic compression profile of the three-dimensional inward-turning intake duct in a direction perpendicular to the meridian plane, the obtained projection curve is the inlet of the array bleed hole; the inlet of the array bleed hole is stretched on both sides in a direction perpendicular to the meridian plane, and the overlapping part of the geometry with the wall surface of the three-dimensional inward-turning intake duct is subtracted to obtain the structure of the array bleed hole; the stretching direction of the array bleed hole is the same as the direction of the central axis of the array circle, and the stretching distance is equal to the wall thickness of the isentropic compression profile of the three-dimensional inward-turning intake duct; taking the bleed hole on the inner surface of the isentropic compression profile of the three-dimensional inward-turning intake duct as the starting stage of stretching as the inlet of the array bleed hole; taking the outer surface of the three-dimensional inward-turning intake duct as the ending stage of stretching as the outlet of the array bleed hole; the internal space of stretching is the array bleed hole of the three-dimensional inward-turning intake duct, and the positions and lengths of the array bleed holes corresponding to both sides of the isentropic compression profile of the three-dimensional inward-turning intake duct are equal to ensure the symmetry of the structure of the three-dimensional inward-turning intake duct; design the profile of the bleed slot inlet for the peripheral part of the outlet of the array bleed hole, and its geometric shape is a curved quadrilateral; the profile of the bleed slot inlet is located on the outer surface of the three-dimensional inward-turning intake duct, in the front part of the shoulder profile of the three-dimensional inward-turning intake duct, and behind the isentropic compression profile of the three-dimensional inward-turning intake duct, and this curved quadrilateral completely surrounds all the outlets of the array bleed holes; the bleed slot is obtained by stretching the profile of the bleed slot inlet along the extension direction of the inlet of the array bleed hole; the bleed slot is bounded by the profile of the bleed slot inlet and the profile of the bleed slot outlet, and the profile of the bleed slot outlet is the intersection line of the bleed slot and the outer cover of the three-dimensional inward-turning intake duct; the positions and sizes of the bleed slots on both sides of the isentropic compression profile of the three-dimensional inward-turning intake duct are the same to ensure the symmetry of the structure of the three-dimensional inward-turning intake duct; the low-speed air flow displaced by the intake duct flows out to the bleed slot through the outlet of the array bleed hole and is displaced to the outside through the outlet of the bleed slot; the boundary layer mainly accumulates in the upper and middle reaches of the isentropic compression profile of the three-dimensional inward-turning intake duct and near the shoulder profile of the three-dimensional inward-turning intake duct.

2. The integrated flow control method for the projectile inlet to improve the internal space utilization rate according to claim 1, wherein The designed structure includes a curved cone projectile, an outer cover of the three-dimensional inward-turning intake duct, the three-dimensional inward-turning intake duct, and a bleed slot device; The curved cone projectile is a curved surface obtained by rotating a multi-curve as the generatrix of the curved cone projectile around the central axis of the cone; The three-dimensional inward-turning intake duct includes an isentropic compression profile of the three-dimensional inward-turning intake duct and an isolation section of the three-dimensional inward-turning intake duct, and the isentropic compression profile of the three-dimensional inward-turning intake duct and the isolation section of the three-dimensional inward-turning intake duct are connected by the shoulder profile of the three-dimensional inward-turning intake duct; the outer cover of the three-dimensional inward-turning intake duct is connected to the curved cone projectile by the connecting line of the outer cover of the three-dimensional inward-turning intake duct, and the outer cover of the three-dimensional inward-turning intake duct places the three-dimensional inward-turning intake duct between the outer cover of the three-dimensional inward-turning intake duct and the curved cone projectile to realize the integrated design of the curved cone projectile and the three-dimensional inward-turning intake duct; The flow discharge groove device includes an array of flow discharge hole inlets, an array of flow discharge holes, an array of flow discharge hole outlets, a flow discharge groove, and a flow discharge groove outlet; the symmetrical meridian plane of the curved surface cone projectile and the three-dimensional internal turning inlet passage is selected, and the meridian plane array of flow discharge hole profiles is designed in the downstream part of the intersection line of the isentropic compression profile of the symmetrical meridian plane, which is an array of circles with equal radii and equal center distances. The projected area of the array of circles on the meridian plane of the isentropic compression profile of the three-dimensional internal turning inlet passage is higher than 2% to achieve the effect of displacing the low-speed air flow in the inlet passage; the projected profile of the array of circles on the inner surface of the isentropic compression profile of the three-dimensional internal turning inlet passage in the direction perpendicular to both sides of the meridian plane is the array of flow discharge hole inlets; the array of flow discharge holes extends along the stretching direction to the outer surface of the isentropic compression profile of the three-dimensional internal turning inlet passage to form an array of pore structures; this pore structure is the array of flow discharge holes, and the intersection line of the array of flow discharge holes and the outer surface of the isentropic compression profile of the three-dimensional internal turning inlet passage is the array of flow discharge hole outlets; on the outer edge of the array of flow discharge hole outlets on both sides, a closed curved surface quadrilateral is designed on the outer surface of the isentropic compression profile of the three-dimensional internal turning inlet passage, and the curved surface quadrilateral is stretched along the extending direction of the array of flow discharge holes to intersect with the outer shroud of the three-dimensional internal turning inlet passage, and the formed intersection line is the outlet part of the flow discharge groove; the flow discharge grooves on both sides of the meridian plane have the same size to ensure the symmetry of the entire device.

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