Geometric throat for RBCC engine

Abstract

The geometric throat used for the RBCC engine comprises a flow channel shell which is of a shell structure with openings in the left side and the right side, and the cross section of the flow channel shell is square or rectangular; the front actuating plate and the rear actuating plate are both located in an inner cavity of the flow channel shell and are arranged close to the bottom of the flow channel shell; the driving oil cylinder is vertically arranged, the piston end of the driving oil cylinder extends upwards, penetrates through the bottom of the runner shell and is hinged to the rear end of the front actuating plate and the front end of the rear actuating plate, the driving oil cylinder is used for pushing the rear end of the front actuating plate and the front end of the rear actuating plate to move upwards, and then the front actuating plate inclines upwards from front to back; the rear actuating plate is inclined downwards from front to back, and the upper wall surfaces of the front actuating plate and the rear actuating plate and the top of the runner shell form a geometric throat; the geometric throat is simple in structure, easy to machine and very easy to seal, can be matched with an adjustable air inlet channel to achieve wide-range change of the expansion ratio of the combustion chamber, and meets the requirement for the expansion ratio of the combustion chamber under different incoming flow Mach numbers.

Description

Technical Field

[0001] The invention belongs to the field of rocket-based combined power cycle engines, and in particular relates to a geometric throat for a RBCC engine. Background Art

[0002] The RBCC engine can realize the aircraft from static takeoff to hypersonic flight, and is an ideal propulsion system for future reusable space transportation and near-space aircraft. The combustion chamber and tail nozzle are key components in the RBCC engine. For air-breathing engines, the combustion chamber must use high-speed airflow to complete the injection, atomization, evaporation, mixing and combustion of fuel within a limited space and time, convert chemical energy into heat energy to the maximum extent, and convert heat energy into kinetic energy to the maximum extent through the tail nozzle to generate thrust.

[0003] In the scramjet mode, in order to meet the requirements of supersonic combustion, the combustion chamber flow path needs to maintain an expansion structure; while in the jet and sub-combustion modes, the combustion chamber flow path can adopt a convergent-expansion structure to achieve efficient combustion. As the flight Mach number increases, the heating ratio in the combustion chamber gradually decreases, and the expansion ratio of the combustion chamber also needs to be reduced accordingly to meet the high performance requirements at different Mach numbers. Under the premise that multiple modes share a flow path, engine variable structure technology is one of the effective ways to ensure its optimal working performance throughout the entire process.

[0004] At present, the application of variable structure combustion chamber is mainly concentrated on dual-mode ramjet engines. For RBCC engines, variable structure solutions are mainly applied to intake and exhaust components, that is, adjustable intake ducts have been widely recognized and applied to maintain intake duct performance under wide working conditions. In order to make the RBCC engine work stably in a wide range and improve its performance, the present invention adjusts the performance of the RBCC engine under a wide range of working conditions by changing the geometric throat height. Summary of the invention

[0005] The object of the present invention is to provide a geometric throat for a RBCC engine to meet the requirements of efficient operation within the range of Ma2-6 and improve the performance of the RBCC engine.

[0006] The present invention adopts the following technical solution: a geometric throat for an RBCC engine, comprising:

[0007] The flow channel housing is a housing structure with left and right openings, and its cross section is square or rectangular;

[0008] The front actuating plate and the rear actuating plate are both located in the inner cavity of the flow channel housing and are arranged close to the bottom of the flow channel housing;

[0009] The driving cylinder is vertically arranged, and its piston end extends upward and passes through the bottom of the flow channel housing, and is respectively hinged to the rear end of the front actuating plate and the front end of the rear actuating plate. The driving cylinder is used to push the rear end of the front actuating plate and the front end of the rear actuating plate to move upward, thereby causing the front actuating plate to tilt upward from front to rear, and the rear actuating plate to tilt downward from front to rear, and causing the upper wall surfaces of the front actuating plate and the rear actuating plate to form a geometric throat with the top of the flow channel housing.

[0010] Furthermore, it also includes: a connecting rod, which is "Y"-shaped and consists of two support rods located on the upper side and a fixed rod located on the lower side, the upper ends of the two support rods are respectively hinged to the lower wall surfaces of the rear end of the front actuating plate and the front end of the rear actuating plate, and their lower ends are hinged to the upper end of the fixed rod, and the lower end of the fixed rod is fixedly connected to the piston end of the driving cylinder.

[0011] Furthermore, it also includes: two slide rails, arranged in a front-to-rear direction, and respectively fixed to the left bottom and the right bottom of the flow channel housing;

[0012] The front end of the front actuating plate and the rear end of the rear actuating plate are fixedly connected to rollers on the left and right sides, and the rollers are used to slide on the slide rails, so that when the rear end of the front actuating plate and the front end of the rear actuating plate move upward, the front end of the front actuating plate and the rear end of the rear actuating plate slide on the slide rails on the left and right sides.

[0013] Furthermore, at Ma2, the included angle between the planes where the lower walls of the front actuating plate and the rear actuating plate are located is 140°; and the included angle between the two support rods is 100°.

[0014] Furthermore, at Ma4, the included angle between the planes where the lower walls of the front actuating plate and the rear actuating plate are located is 87.2°; and the included angle between the two support rods is 68.4°.

[0015] Furthermore, at Ma6, the included angle between the planes where the lower walls of the front actuating plate and the rear actuating plate are located is 68°; and the included angle between the two support rods is 54.2°.

[0016] The beneficial effects of the present invention are:

[0017] In the present invention, as the Mach number increases, the driving cylinder drives the front actuating plate and the rear actuating plate to move upward through the connecting rod, so that the rear end of the front actuating plate and the front end of the rear actuating plate are constantly close to the top of the flow channel shell, thereby gradually reducing the height of the geometric throat, thereby meeting the requirement of the combustion chamber for the throat height under high Mach number;

[0018] The invention changes the height of the geometric throat of the RBCC engine by driving the oil cylinder to drive the connecting rod up and down, thereby changing the expansion ratio of the combustion chamber to achieve geometric congestion, and can realize free adjustment of the throat height from 60mm to 160mm, meeting the requirements of different incoming flow Mach numbers within the range of Ma2-6;

[0019] The geometric throat of the present invention has a simple structure, is easy to process, and is very easy to seal. It can cooperate with the adjustable air inlet to achieve a wide range of changes in the combustion chamber expansion ratio and meet the requirements of the combustion chamber expansion ratio under different incoming flow Mach numbers. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 It is a perspective view of the flow channel housing of the present invention.

[0022] Among them: 1. flow channel housing; 2. rear actuating plate; 3. driving cylinder; 4. connecting rod; 5. front actuating plate; 7. slide rail. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. The "direction" in the present invention is based on the position of the present invention in a certain direction. Figure 1 Description of the trend in the state.

[0025] The present invention discloses a geometric throat for a RBCC engine, such as Figure 1 As shown, it includes: a flow channel housing 1, a front actuating plate 5 and a rear actuating plate 2, and a driving cylinder 3.

[0026] The flow channel housing 1 is a housing structure with left and right openings, and the cross section of the flow channel housing 1 is square or rectangular; the front actuating plate 5 and the rear actuating plate 2 are both located in the inner cavity of the flow channel housing 1 and are arranged close to the bottom of the flow channel housing 1.

[0027] The driving cylinder 3 is vertically arranged, and the piston end of the driving cylinder 3 extends upward and passes through the bottom of the flow channel housing 1, and is hinged to the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 respectively. The driving cylinder 3 is used to push the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 to move upward, thereby making the front actuating plate 5 tilt upward from front to rear, and the rear actuating plate 2 tilt downward from front to rear, and making the upper wall surfaces of the front actuating plate 5 and the rear actuating plate 2 form a geometric throat with the top of the flow channel housing 1.

[0028] The present invention also includes: a connecting rod 4, which is "Y"-shaped, and is composed of two support rods located on the upper side and a fixed rod located on the lower side. The upper ends of the two support rods are respectively hinged to the rear end of the front actuating plate 5 and the lower wall surface of the front end of the rear actuating plate 2, and the lower ends of the two support rods are hinged to the upper end of the fixed rod, and the lower end of the fixed rod is fixedly connected to the piston end of the driving cylinder 3.

[0029] like Figure 2 As shown, the present invention further includes: two slide rails 7, both of which are arranged in a front-to-back direction, and the two slide rails 7 are respectively fixed to the left bottom and the right bottom of the flow channel housing 1; therefore, the left and right sides of the front end of the front actuating plate 5 and the rear end of the rear actuating plate 2 are fixedly connected with rollers, and the rollers are used to slide on the slide rails 7, so that when the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 move upward, the left and right sides of the front end of the front actuating plate 5 and the rear end of the rear actuating plate 2 slide on the slide rails 7.

[0030] Preferably, at Ma2, the included angle between the planes where the lower walls of the front actuating plate 5 and the rear actuating plate 2 are located is 140°; and the included angle between the two supporting rods is 100°.

[0031] Preferably, at Ma4, the included angle between the planes where the lower walls of the front actuating plate 5 and the rear actuating plate 2 are located is 87.2°; and the included angle between the two supporting rods is 68.4°.

[0032] Preferably, at Ma6, the included angle between the planes where the lower walls of the front actuating plate 5 and the rear actuating plate 2 are located is 68°; and the included angle between the two supporting rods is 54.2°.

[0033] In the present invention, when the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 move upward, the angle between the two support rods also changes accordingly, so that the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 are always in contact with each other and in a sealed state, thereby preventing the high-temperature gas in the geometric throat from leaking from the gap between the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2.

[0034] Example 1

[0035] The size of the geometric throat of this embodiment is based on the intake duct capture area of ​​0.04m 2The engine is designed based on the engine size. When the engine size changes, it is only necessary to reduce the geometric throat ratio. The specific parameters are as follows:

[0036] When the incoming flow Mach number is 2, the inlet height of the isolation section is 50 mm. In order to meet the requirements of the combustion chamber expansion ratio, the height of the geometric throat is 160 mm. At this time, the front actuating plate 5 and the rear actuating plate 2 are in the initial position, that is, the angle between the planes where the lower walls of the front actuating plate 5 and the rear actuating plate 2 are located is 140°.

[0037] When the incoming flow Mach number is 4, the entrance height of the isolation section becomes 38.5 mm. In order to meet the requirements of the combustion chamber expansion ratio, the driving cylinder 3 is used to drive the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 to move upward until the distance between the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 and the top of the flow channel housing 1 is 84.7 mm, that is, the height of the geometric throat is 84.7 mm. At this time, the angle between the planes where the lower walls of the front actuating plate 5 and the rear actuating plate 2 are located is 87.2°.

[0038] When the incoming flow Mach number is 6, the entrance height of the isolation section is still 38.5 mm. In order to meet the requirements of the combustion chamber expansion ratio, the driving cylinder 3 is used to continue to drive the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 to move upward until the distance between the rear end of the front actuating plate 5 and the front end of the rear actuating plate 2 and the top of the flow channel housing 1 is 61.6 mm, that is, the height of the geometric throat is 61.6 mm. At this time, the angle between the planes where the lower walls of the front actuating plate 5 and the rear actuating plate 2 are located is 68°.

[0039] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A geometric throat for an RBCC engine, characterized in that: include: The flow channel housing (1) is a housing structure with left and right openings, and its cross section is square or rectangular; The front actuating plate (5) and the rear actuating plate (2) are both located in the inner cavity of the flow channel housing (1) and are arranged close to the bottom of the flow channel housing (1); The driving cylinder (3) is arranged vertically, and its piston end extends upward and passes through the bottom of the flow channel housing (1), and is respectively hinged to the rear end of the front actuating plate (5) and the front end of the rear actuating plate (2). The driving cylinder (3) is used to push the rear end of the front actuating plate (5) and the front end of the rear actuating plate (2) to move upward, thereby causing the front actuating plate (5) to tilt upward from front to rear, and the rear actuating plate (2) to tilt downward from front to rear, and causing the upper wall surfaces of the front actuating plate (5) and the rear actuating plate (2) to form a geometric throat with the top of the flow channel housing (1).

2. A geometric throat for a RBCC engine according to claim 1, characterized in that: Also includes: The connecting rod (4) is in a "Y" shape and consists of two support rods located on the upper side and a fixed rod located on the lower side. The upper ends of the two support rods are respectively hinged to the rear end of the front actuating plate (5) and the lower wall surface of the front end of the rear actuating plate (2), and the lower ends thereof are hinged to the upper end of the fixed rod. The lower end of the fixed rod is fixedly connected to the piston end of the driving cylinder (3).

3. A geometric throat for a RBCC engine according to claim 1, characterized in that: Also includes: Two slide rails (7) are arranged in a front-to-rear direction and are respectively fixed to the left bottom and the right bottom of the flow channel housing (1); The front end of the front actuating plate (5) and the rear end of the rear actuating plate (2) are fixedly connected to rollers on the left and right sides, and the rollers are used to slide on the slide rails (7), so that when the rear end of the front actuating plate (5) and the front end of the rear actuating plate (2) move upward, the front end of the front actuating plate (5) and the rear end of the rear actuating plate (2) slide on the slide rails (7).

4. A geometric throat for a RBCC engine according to claim 2, characterized in that: At Ma2, the included angle between the planes where the lower walls of the front actuating plate (5) and the rear actuating plate (2) are located is 140°; and the included angle between the two support rods is 100°.

5. A geometric throat for a RBCC engine according to claim 2, characterized in that: At Ma4, the included angle between the planes where the lower walls of the front actuating plate (5) and the rear actuating plate (2) are located is 87.2°; and the included angle between the two support rods is 68.4°.

6. A geometric throat for a RBCC engine according to claim 2, characterized in that: At Ma6, the included angle between the planes where the lower walls of the front actuating plate (5) and the rear actuating plate (2) are located is 68°; and the included angle between the two support rods is 54.2°.

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