A variable isolation section device for an axisymmetric air intake

Abstract

The present invention relates to a variable isolation section device for an axisymmetric air intake duct, comprising: an air intake duct outer cover, a central cone, a cylindrical inner tube and a variable isolation section; the air intake duct outer cover is a hollow cylindrical body; the central cone, the cylindrical inner tube and the variable isolation section are all arranged in the hollow part of the air intake duct outer cover; wherein the central cone and the cylindrical inner tube are arranged in front of the cylindrical inner tube with an interval; the hollow part of the cylindrical inner tube constitutes a cylindrical combustion chamber, and the hollow part between the cylindrical inner tube and the air intake duct outer cover constitutes an annular combustion chamber; the variable isolation section is arranged at the front end of the cylindrical inner tube; the variable isolation section and the cylindrical inner tube can move together in the axial direction, and the combustion chamber inlets of the cylindrical combustion chamber and the annular combustion chamber are switched on and off.

Description

Technical Field

[0001] The invention relates to the field of aerospace science and technology, and in particular to a variable isolation section device for an axisymmetric air inlet. Background Art

[0002] As the demand for power systems to operate over a wide speed range and large airspace continues to increase, combined power that integrates the performance advantages of different types of engines has become a key research direction for various countries.

[0003] Engines used in different airspeed ranges sometimes have different inherent geometric configurations, such as cylindrical and annular. When combined power uses engines with different combustion chamber configurations as engines in different airspeed ranges, matching the inlet duct with different combustion chambers becomes a problem that must be solved.

[0004] In a typical supersonic axisymmetric inlet translation variable geometry scheme, the center cone moves forward and backward as a whole, changing the geometry of the inlet, and then changing the aerodynamic performance of the inlet, so as to meet the air intake demand in a wide speed range. The throat section is arranged in the turning section of the lip cover to the axis. When the mode conversion process is carried out, the position of the throat changes through the forward movement of the center cone, and the throat area becomes larger, and the flow performance of the inlet increases, so as to achieve the purpose of efficiently adjusting the performance of the inlet. When the inlet is started, the incoming flow Mach number will move the center cone backward to obtain the maximum flow capture, thereby increasing the compression of the inlet. In the TBCC combined propulsion inlet translation variable geometry scheme, other researchers realize the switching of turbine and ramjet modes by translating the top, middle and bottom of the binary inlet. For the axisymmetric inlet, the inlet mode is switched on and off through an umbrella-like structure. However, the current combustion chambers are cylindrical and annular, respectively, with significant differences in configuration. The existing axisymmetric variable inlet solution can adjust the aerodynamic performance of the inlet by moving the center cone, but it cannot switch between a cylindrical combustion chamber and an annular combustion chamber. The umbrella-mounted variable geometry inlet, although it can switch between cylindrical and annular combustion chambers, has a narrow adjustment range for the geometric performance of the inlet, and a complex structure. The three-dimensional characteristics of the umbrella structure can easily affect the performance of the inlet. The existing extended outer casing solution can realize the switching of the turbine combustion chamber (cylindrical) and flow regulation. However, the outer annular flow channel cannot be switched, and its geometric surface cannot be accurately designed. As the flow channel for high-speed airflow, the outer annular flow channel has a very large impact on the performance of the ramjet combustion chamber due to its surface design. The ideal performance cannot be achieved using a simple extended outer casing. Summary of the invention

[0005] The object of the present invention is to provide a variable isolation section device for an axisymmetric air inlet.

[0006] To achieve the above-mentioned object of the invention, the present invention provides a variable isolation section device for an axisymmetric air inlet, comprising: an air inlet cover, a central cone, a cylindrical inner tube and a variable isolation section;

[0007] The air inlet cover is a hollow cylindrical body;

[0008] The central cone, the cylindrical inner tube and the variable isolation section are all arranged in the hollow part of the air inlet cover; wherein the central cone is arranged in front of the cylindrical inner tube with a gap between the central cone and the cylindrical inner tube;

[0009] The hollow portion of the cylindrical inner tube constitutes a cylindrical combustion chamber, and the hollow portion between the cylindrical inner tube and the air inlet duct outer cover constitutes an annular combustion chamber;

[0010] The variable isolation section is arranged at the front end of the cylindrical inner tube;

[0011] The variable isolation section and the cylindrical inner tube can move together in the axial direction, and control the opening and closing of the combustion chamber inlets of the cylindrical combustion chamber and the annular combustion chamber.

[0012] According to one aspect of the present invention, the variable isolation segment comprises: a first isolation segment portion, a second isolation segment portion and a telescopic structure;

[0013] The first isolation segment part and the second isolation segment part are coaxially sleeved on the outside of the second isolation segment part, and the first isolation segment part and the second isolation segment part are slidably connected to each other;

[0014] The telescopic structure is connected to the first isolation segment portion and the second isolation segment portion respectively, and is used to control the relative position of the first isolation segment portion and the second isolation segment portion;

[0015] The first isolation section is coaxially fixedly connected to the cylindrical inner tube.

[0016] According to one aspect of the present invention, the first isolation segment portion includes: a first cylindrical portion and a first switch portion;

[0017] The first switch part is a cylindrical structure with a large opening at one end and a small opening at the other end; wherein the small diameter end of the first switch part is fixedly connected to one end of the first cylindrical part, and the other end of the first cylindrical part is coaxially fixedly connected to the front end of the cylindrical inner tube;

[0018] The maximum diameter of the large-diameter end of the first switch portion is greater than or equal to the maximum diameter of the combustion chamber inlet of the annular combustion chamber.

[0019] According to one aspect of the present invention, the second isolation segment portion comprises: a second cylindrical portion and a second switch portion;

[0020] The second switch part is a cylindrical structure with a large opening at one end and a small opening at the other end; wherein the small diameter end of the second switch part is fixedly connected to one end of the second cylindrical part, and the other end of the second cylindrical part is coaxially slidably connected to the first cylindrical part;

[0021] The maximum diameter of the large-diameter end of the second switch portion is greater than or equal to the maximum diameter of the large-diameter end of the first switch portion.

[0022] According to one aspect of the present invention, when the large diameter end of the second switch part abuts against the large diameter end of the first switch part, a mounting cavity is formed between the second switch part and the first switch part, and the telescopic structure is located in the mounting cavity and is respectively connected to the opposite sides of the second switch part and the first switch part.

[0023] According to one aspect of the present invention, the large diameter end of the second switch portion is provided with an annular skirt;

[0024] One end of the annular skirt is fixedly connected to the edge of the large-diameter end of the second switch portion, and the other end thereof is inclinedly extended toward a direction close to the small-diameter end of the second switch portion.

[0025] According to one aspect of the present invention, a plurality of pressure relief holes / slits penetrating the body of the annular skirt are arranged at intervals on the annular skirt along the circumference of the annular skirt.

[0026] According to one aspect of the present invention, along the direction from the large diameter end to the small diameter end of the second switch portion, the size and shape of the outer surface of the annular skirt are matched with the size and shape of the inner side wall of the first switch portion.

[0027] According to one aspect of the present invention, the central cone is movable in the axial direction and / or telescopically deformable.

[0028] According to one solution of the present invention, the shape of the combustion chamber connected with the air inlet can be changed by the common translation of the isolation section and the cylindrical inner tube, thereby solving the use requirements of matching the engine with the air inlet in different modes from low speed to high speed working stage, so as to meet the use requirements of the aircraft in a wide range of flight airspeed range.

[0029] According to one solution of the present invention, the present invention aims at switching between annular and axisymmetric inlet profiles, and achieves matching of two different combustion chamber inlets, annular and circular, by moving the isolating section and the cylindrical inner tube together forward and backward, thereby achieving conversion of two different flight states. At the same time, a leakage ring / leakage hole can be generated by setting a telescopic device on the isolating section, and a flow regulation channel is provided for possible inlet failure. In order to achieve the best performance of the combined propulsion device under high and low speed conditions.

[0030] According to one solution of the present invention, the present invention realizes the mode conversion of the annular combustion chamber and the cylindrical combustion chamber, which is beneficial for the engines using the two configurations of combustion chambers to work in parallel.

[0031] According to one solution of the present invention, the present invention can accurately adjust the moving distance of the variable isolation section. When the variable isolation section abuts against the central cone, the air inlet works in a high Mach number mode, and the isolation section moves a short distance away from the central cone, which can provide a pressure relief annular gap for a large area separation flow, thereby improving the applicability of the air inlet in a wide Mach number range.

[0032] According to one solution of the present invention, by adding a skirt at the end of the second switch portion, the pressure relief position and the pressure relief flow can be accurately set, and the circumferential discharge flow can be arranged more accurately, further improving the control accuracy and low-speed starting performance of the present solution during low-speed starting.

[0033] According to one solution of the present invention, a plurality of pressure relief holes / slits penetrating the body of the annular skirt are arranged at intervals along the circumference of the annular skirt, and the pressure relief holes / slits are arranged to better enhance the low-speed starting performance of the air intake duct and to adjust the non-starting of the air intake duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a structural diagram schematically showing an opening mode of an annular combustion chamber in a variable isolation section device according to an embodiment of the present invention;

[0035] Figure 2 is a structural diagram schematically showing an opening mode of a cylindrical combustion chamber in a variable isolation section device according to an embodiment of the present invention;

[0036] Figure 3 is a partial structural diagram schematically showing an opening leakage ring of a variable isolation section device according to an embodiment of the present invention;

[0037] Figure 4 is a schematic structural diagram showing a variable isolation section device opening a leakage hole according to an embodiment of the present invention;

[0038] Figure 5 It is a partial structural diagram schematically showing an opening leakage hole of a variable isolation section device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] 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 are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] When describing the embodiments of the present invention, the orientation or positional relationship expressed by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the relevant drawings and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0041] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not therefore limited to the following embodiments.

[0042] Combination Figure 1 , Figure 2 As shown, according to one embodiment of the present invention, a variable isolation section device for an axisymmetric air inlet of the present invention comprises: an air inlet cover 1, a central cone 2, a cylindrical inner tube 3 and a variable isolation section 4. In this embodiment, the air inlet cover 1 is a hollow cylindrical body. Among them, the central cone 2, the cylindrical inner tube 3 and the variable isolation section 4 are all arranged in the hollow part of the air inlet cover 1; wherein the central cone 2 and the cylindrical inner tube 3 are arranged in front of the cylindrical inner tube 3 with an interval. In this embodiment, the hollow part of the air inlet cover 1 comprises: a first hollow section, a second hollow section and a third hollow section arranged in sequence; the inner diameter of the first hollow section is greater than the inner diameter of the third hollow section, and the second hollow section is a transition section and has a conical structure.

[0043] In this embodiment, the central cone 2 and the hollow part of the cylindrical inner tube 3 form an air inlet; the hollow part of the cylindrical inner tube 3 forms a cylindrical combustion chamber 31, and the hollow part between the cylindrical inner tube 3 and the air inlet cover 1 forms an annular combustion chamber 11; the variable isolation section 4 is arranged at the front end of the cylindrical inner tube 3. In this embodiment, the variable isolation section 4 and the cylindrical inner tube 3 can move together in the axial direction, and the combustion chamber inlets of the cylindrical combustion chamber 31 and the annular combustion chamber 11 are switched on and off.

[0044] Combination Figure 1 , Figure 2As shown, according to one embodiment of the present invention, the variable isolation segment 4 includes: a first isolation segment portion 41, a second isolation segment portion 42 and a telescopic structure 43. In this embodiment, the first isolation segment portion 41 and the second isolation segment portion 42 are coaxially sleeved on the outside of the second isolation segment portion 42, and the first isolation segment portion 41 and the second isolation segment portion 42 are slidably connected to each other. In this embodiment, the telescopic structure 43 is respectively connected to the first isolation segment portion 41 and the second isolation segment portion 42, and is used to control the relative position of the first isolation segment portion 41 and the second isolation segment portion 42. In this embodiment, the first isolation segment portion 41 is coaxially fixedly connected to the cylindrical inner tube 3.

[0045] Combination Figure 1 , Figure 2 As shown, according to an embodiment of the present invention, the first isolation section part 41 includes: a first cylindrical part 411 and a first switch part 412. In this embodiment, the first switch part 412 is a cylindrical structure with a large opening at one end and a small opening at the other end; wherein, the small diameter end of the first switch part 412 is fixedly connected to one end of the first cylindrical part 411, and the other end of the first cylindrical part 411 is coaxially fixedly connected to the front end of the cylindrical inner tube 3. In this embodiment, the maximum diameter of the large diameter end of the first switch part 412 is greater than or equal to the maximum diameter of the combustion chamber entrance of the annular combustion chamber 11. In this embodiment, the outer diameter size (outer profile) of the first switch part 412 corresponds to the high-speed mode of the annular combustion chamber 11, and the high-speed airflow still has a high flow rate after deceleration and supercharging through the intake duct. The intake duct and the annular combustion chamber 11 are matched through the isolation section channel formed by the outer cover 1 and the outer side wall of the first switch part 412, so that the total pressure and flow loss of the airflow in the isolation section are minimized.

[0046] Combination Figure 1 , Figure 2 As shown, according to an embodiment of the present invention, the second isolation section 42 includes: a second cylindrical portion 421 and a second switch portion 422. In this embodiment, the second switch portion 422 is a cylindrical structure with a large opening at one end and a small opening at the other end; wherein the small diameter end of the second switch portion 422 is fixedly connected to one end of the second cylindrical portion 421, and the other end of the second cylindrical portion 421 is coaxially slidably connected to the first cylindrical portion 411. In this embodiment, the maximum diameter of the large diameter end of the second switch portion 422 is greater than or equal to the maximum diameter of the large diameter end of the first switch portion 412.

[0047] In this embodiment, the inner diameter size (inner profile) of the second switch portion 422 corresponds to the low-speed mode of the cylindrical combustion chamber 31, and the isolation section channel formed by the central cone 2 of the intake duct and the inner wall of the second switch portion 422 is connected to the cylindrical combustion chamber, so that the combustion chamber can obtain sufficient gas flow in the low-speed mode, and the total pressure and flow loss are minimized.

[0048] Combination Figure 1 , Figure 2 As shown, according to one embodiment of the present invention, when the large diameter end of the second switch portion 422 abuts against the large diameter end of the first switch portion 412, a mounting cavity is formed between the second switch portion 422 and the first switch portion 412, and the telescopic structure 43 is located in the mounting cavity and is respectively connected to the second switch portion 422 and the first switch portion 412 on opposite sides.

[0049] According to the present invention, by configuring the variable isolation section 4 to be two coaxially sleeved parts and arranging a telescopic device between the two parts, a pressure relief annular gap can be provided for the first isolation section part 41 through the action of the telescopic device. Figure 3 As shown, the first isolation section 41 matches the annular combustion chamber 11. When the intake duct works at a non-design point, the intake duct and the isolation section are prone to local boundary layer separation due to the adverse pressure gradient, and then the telescopic device is extended, so that a certain gap is generated between the first isolation section 41 and the second isolation section 42 at the large diameter end, and the gap can be used as a pressure relief ring of the isolation section. This can effectively enhance the starting performance of the intake duct and help the intake duct achieve low-speed starting.

[0050] Combination Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, according to another embodiment of the present invention, the large diameter end of the second switch portion 422 is provided with an annular skirt 422a. In this embodiment, one end of the annular skirt 422a is fixedly connected to the edge of the large diameter end of the second switch portion 422, and the other end extends obliquely toward the direction close to the small diameter end of the second switch portion 422. In this embodiment, when the large diameter end of the second switch portion 422 abuts against the large diameter end of the first switch portion 412, the annular skirt 422a is just accommodated in the installation cavity formed between the second switch portion 422 and the first switch portion 412. When the telescopic device separates the first isolation section 41 and the second isolation section 42, an annular pressure relief ring can also be formed between the annular skirt 422a and the large diameter end of the first isolation section 41, which can effectively enhance the starting performance of the air intake duct and help the air intake duct achieve low-speed starting.

[0051] Combination Figure 1 , Figure 2 , Figure 4 and Figure 5As shown, according to an embodiment of the present invention, along the circumference of the annular skirt 422a, a plurality of pressure relief holes / slits 422a1 are arranged at intervals on the annular skirt 422a and penetrate the body thereof. When the telescopic device separates the first isolation section 41 from the second isolation section 42, an annular pressure relief ring and the pressure relief holes arranged at intervals can be formed between the annular skirt 422a and the large diameter end of the first isolation section 41, further effectively enhancing the starting performance of the air intake duct and helping the air intake duct to achieve low-speed starting.

[0052] like Figure 5 As shown, according to an embodiment of the present invention, along the direction from the large diameter end to the small diameter end of the second switch portion 422, the size and shape of the outer surface of the annular skirt 422a are matched with the size and shape of the inner wall of the first switch portion 412, so that when the ends of the second switch portion 422 and the first switch portion 412 are against each other, the outer surface of the annular skirt 422a can be attached to the inner wall of the first switch portion 412, ensuring the airtightness during connection. The thickness of the annular skirt 422a is set according to the performance requirements of the pressure relief hole. In this embodiment, the size, configuration, arrangement and hole density of the pressure relief hole 422a on the annular skirt 422a are set according to the flight mission and the location of the boundary layer separation of the axisymmetric inlet. In order to better enhance the low-speed starting performance of the air inlet and adjust the non-starting of the air inlet.

[0053] According to the present invention, when it is necessary to close the combustion chamber inlet of the annular combustion chamber 11, the variable isolation section 4 and the cylindrical inner tube 3 are driven by a hydraulic mechanism or an electric mechanism to move in a direction away from the central cone 2 until the large diameter end of the first switch portion 412 in the variable isolation section 4 abuts against the end of the third hollow section of the hollow portion of the intake duct outer cover 1, thereby achieving the shutoff of the annular combustion chamber 11, and the corresponding intake duct is in a low-speed mode at this time; when it is necessary to close the cylindrical combustion chamber 31, the variable isolation section 4 and the cylindrical inner tube 3 are driven by a hydraulic mechanism or an electric mechanism to move in a direction close to the central cone 2 until the large diameter end of the first switch portion 412 in the variable isolation section 4 abuts against the end of the central cone 2, thereby achieving the shutoff of the cylindrical combustion chamber 31, and the corresponding intake duct is in a high-speed mode at this time.

[0054] According to one embodiment of the present invention, the central cone 2 can move and / or deform in the axial direction. Through the above arrangement, the central cone 2 can move and / or deform in the axial direction to make the air inlet meet the air inlet requirements under different flow conditions. In addition, through the coordinated work of the front and rear translation of the central cone and the variable isolation section, the air inlet can be well matched with the cylindrical combustion chamber (turbine engine) and the annular combustion chamber from low speed to high speed.

[0055] The above contents are merely examples of specific solutions of the present invention. For devices and structures not described in detail therein, it should be understood that they can be implemented by adopting general devices and general methods available in the art.

[0056] The above is only one solution of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A variable isolation section device for an axisymmetric air inlet, characterized in that: include: An air inlet cover (1), a central cone (2), a cylindrical inner tube (3) and a variable isolation section (4); The air inlet cover (1) is a hollow cylindrical body; The central cone (2), the cylindrical inner tube (3) and the variable isolation section (4) are all arranged in the hollow part of the air inlet cover (1); wherein the central cone (2) is arranged in front of the cylindrical inner tube (3) with a gap between the central cone (2) and the cylindrical inner tube (3); The hollow portion of the cylindrical inner tube (3) forms a cylindrical combustion chamber (31), and the hollow portion between the cylindrical inner tube (3) and the air inlet duct outer cover (1) forms an annular combustion chamber (11); The variable isolation section (4) is arranged at the front end of the cylindrical inner tube (3); The variable isolation section (4) and the cylindrical inner tube (3) can move together in the axial direction, and control the opening and closing of the combustion chamber inlets of the cylindrical combustion chamber (31) and the annular combustion chamber (11).

2. The variable isolation section device according to claim 1, characterized in that: The variable isolation segment (4) comprises: a first isolation segment portion (41), a second isolation segment portion (42) and a telescopic structure (43); The first isolating segment portion (41) and the second isolating segment portion (42) are coaxially sleeved on the outside of the second isolating segment portion (42), and the first isolating segment portion (41) and the second isolating segment portion (42) are slidably connected to each other; The telescopic structure (43) is connected to the first isolation segment portion (41) and the second isolation segment portion (42) respectively, and is used to control the relative position of the first isolation segment portion (41) and the second isolation segment portion (42); The first isolation section (41) is coaxially fixedly connected to the cylindrical inner tube (3).

3. The variable isolation section device according to claim 2, characterized in that: The first isolation section (41) comprises: a first cylindrical portion (411) and a first switch portion (412); The first switch portion (412) is in a cylindrical structure with a larger opening at one end and a smaller opening at the other end; wherein the small-diameter end of the first switch portion (412) is fixedly connected to one end of the first cylindrical portion (411), and the other end of the first cylindrical portion (411) is coaxially fixedly connected to the front end of the cylindrical inner tube (3); The maximum diameter of the large-diameter end of the first switch portion (412) is greater than or equal to the maximum diameter of the combustion chamber inlet of the annular combustion chamber (11).

4. The variable isolation section device according to claim 3, characterized in that: The second isolation section (42) comprises: a second cylindrical portion (421) and a second switch portion (422); The second switch part (422) is in a cylindrical structure with a larger opening at one end and a smaller opening at the other end; wherein the small diameter end of the second switch part (422) is fixedly connected to one end of the second cylindrical part (421), and the other end of the second cylindrical part (421) is coaxially slidably connected to the first cylindrical part (411); The maximum diameter of the large diameter end of the second switch portion (422) is greater than or equal to the maximum diameter of the large diameter end of the first switch portion (412).

5. The variable isolation section device according to claim 4, characterized in that: When the large diameter end of the second switch part (422) abuts against the large diameter end of the first switch part (412), a mounting cavity is formed between the second switch part (422) and the first switch part (412), and the telescopic structure (43) is located in the mounting cavity and is respectively connected to the second switch part (422) and the first switch part (412) on opposite sides.

6. The variable isolation section device according to claim 5, characterized in that: The large diameter end of the second switch portion (422) is provided with an annular skirt (422a); One end of the annular skirt (422a) is fixedly connected to the edge of the large diameter end of the second switch portion (422), and the other end extends obliquely toward the direction close to the small diameter end of the second switch portion (422).

7. The variable isolation section device according to claim 6, characterized in that: Along the circumference of the annular skirt (422a), a plurality of pressure relief holes / slits (422a1) penetrating the body of the annular skirt (422a) are arranged at intervals on the annular skirt (422a).

8. The variable isolation section device according to claim 7, characterized in that: Along the direction from the large diameter end to the small diameter end of the second switch portion (422), the size and shape of the outer surface of the annular skirt (422a) are arranged to match the size and shape of the inner side wall of the first switch portion (412).

9. The variable isolation section device according to claim 8, characterized in that: The central cone (2) can move in the axial direction and / or deform in a telescopic manner.

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