A parallel combined air intake with mode switching and its control method

Abstract

This invention discloses a novel parallel-connected air intake with a novel mode-switching mechanism and its control method. The air intake includes an adjustable lip cover, an outer cylinder, and a drive system, all coaxially arranged. Inside the outer cylinder are a central cone, a central cone support, a tail cone sleeve, and a flow channel partition plate, arranged sequentially from front to back, all coaxial with the outer cylinder. The central cone and the central cone support are slidable relative to each other. The tail cone sleeve is fitted onto the tail of the central cone support and can slide along the support to move closer to or further away from the front end of the flow channel partition plate. The outer cylinder also contains a cylindrical fish-scale-shaped array. The drive system can adjust the angle between the fish-scale-shaped array and the air intake axis to move the other end of the fish-scale-shaped array closer to or further away from the front end of the flow channel partition plate. This invention achieves mode switching of the air intake through the cooperation of the tail cone sleeve and the fish-scale-shaped array, solving the problem of difficult mode switching in wide-range air intakes. This allows the air intake to operate over a wider flight speed and airspace range, and the mode-switching control method is simple.

Description

Technical Field

[0001] This invention relates to the field of aircraft design technology, and in particular to an internal parallel combined air intake with a mode switching method and a control method thereof. Background Technology

[0002] As the power plant for hypersonic vehicles, the operating characteristics of air-breathing combined cycle engines directly determine the flight speed range, airspace, and mission capabilities of hypersonic vehicles. Common types include turbine-based combined cycle (TBCC) engines, rocket-based combined cycle (RBCC) engines, and air-turbo rocket (ATR) engines. Although combined cycle engines come in various forms, they are essentially air-breathing propulsion systems, thus requiring an upstream air intake to capture and compress the incoming airflow with high quality. However, because the air intake must simultaneously face the extremely wide speed and airspace range of the upstream incoming airflow (Mach number 0–6+, altitude 0–30 km), as well as multiple operating channels and modes of the downstream engine (≥2 operating channels, ≥3 operating modes), its complexity far exceeds that of traditional aircraft air intakes (Mach number 0–2, altitude 0–20 km; single channel, single mode). Axisymmetric adjustable inlets are a commonly used type of wide-range inlet design, with mature engineering application technology. However, mode switching technology for axisymmetric inlets remains a challenge. Therefore, a novel inlet design is needed for wide-range axisymmetric adjustable inlets to simultaneously meet the requirements of mode switching and wide-range geometric adjustment of the inlet. Summary of the Invention

[0003] Purpose of the invention: To address the shortcomings of existing axisymmetric air intakes in terms of difficulty in mode switching, this invention provides an internal parallel combined air intake with a mode switching method and a control method.

[0004] Technical Solution: To solve the above problems, the present invention adopts an internal parallel combined air intake with a mode switching method, including an adjustable lip cover, an air intake outer cylinder, and a drive system arranged coaxially. The adjustable lip cover is fitted onto the front end of the air intake outer cylinder and can slide along the outer wall of the air intake outer cylinder. The inner side of the air intake outer cylinder is provided with a central cone, a central cone support, a tail cone sleeve, and a flow channel partition plate arranged coaxially with the air intake outer cylinder and from front to back. There is a certain gap between the air intake outer cylinder and the central cone, central cone support, tail cone sleeve, and flow channel partition plate. One end of the central cone is located inside the air intake outer cylinder and connected to the central cone support, and the other end of the central cone extends out of the adjustable lip cover. The central cone and the central cone support can slide relative to each other. The tail cone sleeve is fitted onto the tail of the central cone support and can slide along the central cone support to approach or move away from the front end of the flow channel partition plate.

[0005] The outer cylinder of the air intake is also equipped with a cylindrical fish scale assembly, which is composed of several fish scales. One end of each fish scale is hinged to the inner wall of the outer cylinder of the air intake. The drive system adjusts the angle between the fish scale and the axis of the air intake so that the other end of the fish scale moves closer to or further away from the front end of the flow channel partition plate. The drive system is also used to control the movement of the center cone, the adjustable lip, and the tail cone sleeve. The inner wall of the flow channel partition plate forms a stamping channel, and the outer wall of the flow channel partition plate and the inner wall of the outer cylinder of the air intake form a turbine channel. When the tail cone sleeve is in contact with the front end of the flow channel partition plate, the stamping channel is closed. When the fish scale assembly is in contact with the front end of the flow channel partition plate, the turbine channel is closed.

[0006] Furthermore, the length of the fish scale is equal to the shortest distance between the hinge point of the fish scale on the outer cylinder of the air intake and the front end of the flow channel partition plate.

[0007] Furthermore, the tail cone sleeve includes a connecting section that contacts the central cone support and a conical section that is close to the flow channel partition plate. The connecting section slides on the outer wall of the central cone support to allow the conical section to move closer to or further away from the flow channel partition plate. When the conical section moves to the position furthest from the central cone support, the tail cone sleeve fits against the front end of the flow channel partition plate.

[0008] Furthermore, the adjustable lip cover is cylindrical, and the outermost front end of the adjustable lip cover has a transition surface with a gradually increasing outer diameter.

[0009] Furthermore, the central cone support is fixed in position, and the central cone support is fixedly connected to the outer cylinder of the air intake through several bleed support plates.

[0010] Furthermore, the flow channel partition plate includes three curved panels that are smoothly connected from front to back. The inner diameters of the three curved panels are all equal and remain unchanged. The outer diameter of the first curved panel remains unchanged, the outer diameter of the second curved panel gradually increases, and the outer diameter of the third curved panel remains unchanged.

[0011] Furthermore, the movement direction of the central cone, adjustable lip cover, and tail cone sleeve is translation along the axial direction.

[0012] Furthermore, the drive system includes a first motor and a second motor installed inside the central cone support, and a third motor and a fourth motor installed on the outer wall of the intake manifold outer cylinder; the output shaft of the first motor is connected to the central cone, the output shaft of the second motor is connected to the tail cone sleeve, the third motor is connected to the adjustable lip cover via a connecting rod, and the output shaft of the fourth motor is connected to the fish scale assembly via a hinge.

[0013] The present invention also provides a control method for the aforementioned internal parallel combined air intake. When the aircraft speed is lower than a preset Mach number, the drive system controls the fish scale assembly to move away from the front end of the flow channel partition and controls the tail cone sleeve to fit against the front end of the flow channel partition, closing the ram air passage and opening the turbine passage. The drive system controls the central cone to move forward to increase the throat area of ​​the air intake to reduce the internal contraction ratio of the air intake, so that the air intake meets the start-up requirements. When the flight Mach number gradually increases, the drive system controls the central cone to move backward to reduce the throat area of ​​the air intake to increase the internal contraction ratio of the air intake. At the same time, the adjustable lip mask is controlled to move in conjunction with the compression cone shock wave to meet the air intake flow capture requirements. When the aircraft speed reaches a preset mode switching Mach number, the drive system controls the fish scale assembly to fit against the front end of the flow channel partition and controls the tail cone sleeve to move away from the front end of the flow channel partition, closing the turbine passage and opening the ram air passage.

[0014] Furthermore, the control of the adjustable lip cover in conjunction with the movement of the compression cone shock wave specifically involves: when the required flow coefficient of the intake duct is large, the adjustable lip cover is moved forward to get closer to the compression cone shock wave; when the required flow coefficient of the intake duct is small, the adjustable lip cover is moved backward to get away from the compression cone shock wave.

[0015] Beneficial effects: Compared with the prior art, the significant advantage of this invention is that it achieves mode switching of the air intake through the cooperation of the tail cone sleeve and the fish scale assembly, which solves the problem of difficult mode switching of the wide-range air intake, enabling the air intake to work in a wider flight speed range and airspace, and the mode switching control method is simple. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the air intake duct of the present invention;

[0017] Figure 2 This is a schematic diagram of the overall structure of the intake duct removal drive system of the present invention;

[0018] Figure 3 This is a schematic diagram of the various structures inside the outer cylinder of the air intake duct of the present invention;

[0019] Figure 4 This is a schematic diagram of the internal structure of the air intake outer cylinder of the fish scale removal assembly of the present invention;

[0020] Figure 5 This is a state diagram of the air intake duct of the present invention in the turbine operating mode;

[0021] Figure 6 This is a state diagram of the air intake duct of the present invention in the stamping working mode;

[0022] Figure 7 This is a schlieren image of the air intake duct of the present invention under wind tunnel test at Mach number 2.5;

[0023] Figure 8This is a schlieren image of the air intake duct of the present invention under wind tunnel test at Mach 3.8;

[0024] Figure 9 This is a schlieren image of the air intake duct of the present invention under wind tunnel test at Mach 6. Detailed Implementation

[0025] like Figures 1 to 4 As shown, this embodiment of an internal parallel combined air intake with a mode switching method includes a central cone 1, an adjustable lip cover 2, an air intake outer cylinder 3, a bleed support plate 4, a central cone support 5, a fish scale assembly 61, a tail cone sleeve 62, a flow channel partition plate 7, and a drive system. The drive system includes a first motor 11 and a second motor 65 installed in the central cone support 5, and a third motor 23 and a fourth motor 63 installed on the outer wall of the air intake outer cylinder 3. The adjustable lip cover 2 and the air intake outer cylinder 3 are coaxially arranged, with the adjustable lip cover 2 fitted onto the front end of the air intake outer cylinder 3. The third motor 23 is installed in a motor support 22 and connected to the adjustable lip cover 2 via a connecting rod 21, driving the adjustable lip cover 2 to slide along the outer wall of the air intake outer cylinder 3. The adjustable lip cover 2 is cylindrical, and the outermost front end of the outer wall of the adjustable lip cover 2 has a transition surface with a gradually increasing outer diameter.

[0026] The inner side of the intake duct outer cylinder 3 is provided with a central cone 1, a central cone support 5, a tail cone sleeve 62, and a flow channel partition plate 7, which are coaxial with the intake duct outer cylinder 3 and arranged sequentially from front to back. A gap is left between the adjustable lip cover 2 and the intake duct outer cylinder 3 on the outer side and the central cone 1, central cone support 5, tail cone sleeve 62, and flow channel partition plate 7 on the inner side to allow airflow to pass through. One end of the central cone 1 is located inside the intake duct outer cylinder 3 and connected to the central cone support 5, while the other end of the central cone 1 extends out of the adjustable lip cover 2. The central cone support 5 is fixedly connected to the intake duct outer cylinder 3 by four venting support plates 4. The venting support plates 4 are used to discharge the low-energy flow released from the central cone vent slot to the outside, acting as a drainage channel. The central cone support 5 is fixed in position and cannot be moved. The tail section of the central cone 1 is sleeved on the front end of the central cone support 5. The output shaft of the first motor 11 is connected to the central cone 1 to drive the central cone 1 to slide relative to the central cone support 5. The tail cone sleeve 62 includes a connecting section fitted onto the tail section of the central cone support 5 and a conical section near the flow channel partition plate 7. The output shaft of the second motor 65 is connected to the conical section, and the second motor 65 drives the tail cone sleeve 62 to move. The connecting section slides on the outer wall of the central cone support 5 to move the conical section closer to or further away from the flow channel partition plate 7. The central cone 1, the adjustable lip 2, and the tail cone sleeve 62 all move in a translational direction along the axial direction.

[0027] The outer cylinder 3 of the air intake also contains a cylindrical fish scale assembly 61, which is composed of several fish scales. These fish scales are interconnected to achieve synchronized movement. One end of each fish scale is hinged to the inner wall of the outer cylinder 3. The output shaft of the fourth motor 63 is connected to the fish scale assembly 61 via a hinge 64. The connection point of the hinge 64 on the fish scale is a certain distance from the other end of the fish scale. The length of the fish scale is equal to the shortest distance between the hinge point of the fish scale on the outer cylinder 3 and the front end of the flow channel partition plate 7. The fourth motor 63 is used to adjust the angle between the fish scale and the axis of the air intake so that the other end of the fish scale moves closer to or further away from the front end of the flow channel partition plate 7.

[0028] The flow channel partition 7 comprises three curved panels smoothly connected from front to back. The inner diameters of the three curved panels are all equal and remain constant. The outer diameter of the first curved panel remains constant, the outer diameter of the second curved panel gradually increases, and the outer diameter of the third curved panel remains constant. The inner wall of the flow channel partition 7 forms a stamping channel 9, and the outer wall of the flow channel partition 7 and the inner wall of the intake manifold outer cylinder 3 form a turbine channel 8. When the tail cone sleeve 62 is in contact with the front end of the flow channel partition 7, the stamping channel 9 is in a closed state. When the fish scale assembly 61 is in contact with the front end of the flow channel partition 7, the turbine channel 8 is in a closed state.

[0029] The intake manifold control method in this embodiment is as follows: Figure 5 As shown, when the aircraft speed is lower than the preset Mach number, the fourth motor 63 controls the scale plate group 61 to move away from the front end of the flow channel partition plate 7 and controls the tail cone sleeve 62 to fit against the front end of the flow channel partition plate 7, closing the ram air passage 9 and opening the turbine passage 8. The first motor 11 controls the central cone 1 to move forward, increasing the throat area of ​​the air intake to reduce the internal contraction ratio of the air intake, so that the air intake meets the starting requirements. As the flight Mach number gradually increases, the first motor 11 controls the central cone 1 to move backward, reducing the throat area of ​​the air intake to increase the internal contraction ratio of the air intake. At the same time, the third motor 23 controls the adjustable lip 2 to move in coordination with the compression cone shock wave to meet the air intake flow capture requirements. Specifically, when the required flow coefficient of the air intake is large, the adjustable lip 2 is moved forward to get closer to the compression cone shock wave; when the required flow coefficient of the air intake is small, the adjustable lip 2 is moved backward to move away from the compression cone shock wave. Figure 6 As shown, when the aircraft speed reaches the preset mode switching Mach number, the fourth motor 63 controls the fish scale assembly 61 to adhere to the front end of the flow channel partition plate 7 and controls the tail cone sleeve 62 to move away from the front end of the flow channel partition plate 7, closing the turbine channel 8 and opening the ramjet channel 9. When the flight Mach number is greater than the mode switching Mach number, the turbine channel 8 remains closed.

[0030] like Figures 7 to 9The figure shows the schlieren images of the air intake in this embodiment at Mach numbers 2.5, 3.8, and 6. If the air intake is in a non-operational state, separation packets will appear on both sides of the central cone and induce separation shock waves. The separation shock waves intersect with the cone shock waves generated by the central cone, which will significantly reduce the capture flow rate of the air intake. As can be seen from the figure, at each Mach number, clear shock wave systems can be observed on both sides of the central cone, and no separation shock waves are generated, indicating that the air intake is in normal working condition and has good capture flow rate performance.

Claims

1. An internal parallel combined air intake with a mode switching method, characterized in that, The system includes an adjustable lip cover (2) coaxially arranged, an air intake outer cylinder (3), and a drive system. The adjustable lip cover (2) is fitted onto the front end of the air intake outer cylinder (3) and can slide along the outer wall of the air intake outer cylinder (3). The inner side of the air intake outer cylinder (3) is provided with a central cone (1), a central cone support (5), a tail cone sleeve (62), and a flow channel partition plate (7) arranged coaxially with the air intake outer cylinder (3) and from front to back. There is a certain gap between the support (5), the tail cone sleeve (62) and the flow channel partition plate (7); one end of the central cone (1) is located inside the outer cylinder (3) of the air intake and is connected to the central cone support (5), and the other end of the central cone (1) extends out of the adjustable lip cover (2). The central cone (1) and the central cone support (5) can slide relative to each other; the tail cone sleeve (62) is sleeved on the tail of the central cone support (5) and can slide along the central cone support (5) to approach or move away from the front end of the flow channel partition plate (7); The outer cylinder (3) of the air intake is also provided with a cylindrical fish scale assembly (61), which is composed of several fish scales. One end of the fish scale is hinged to the inner wall of the outer cylinder (3) of the air intake. The drive system adjusts the angle between the fish scale and the axis of the air intake so that the other end of the fish scale is close to or away from the front end of the flow channel partition plate (7). The drive system is also used to control the movement of the center cone (1), the adjustable lip cover (2) and the tail cone sleeve (62). The inner wall of the flow channel partition plate (7) forms a stamping channel (9), and the outer wall of the flow channel partition plate (7) and the inner wall of the outer cylinder (3) of the air intake form a turbine channel (8). When the tail cone sleeve (62) is in contact with the front end of the flow channel partition plate (7), the stamping channel (9) is in a closed state. When the fish scale assembly (61) is in contact with the front end of the flow channel partition plate (7), the turbine channel (8) is in a closed state.

2. The internal parallel combined air intake as described in claim 1, characterized in that, The length of the fish scale is equal to the shortest distance between the hinge point of the fish scale on the outer cylinder (3) of the air intake and the front end of the flow channel partition plate (7).

3. The internal parallel combined air intake as described in claim 2, characterized in that, The tail cone sleeve (62) includes a connecting section that contacts the central cone support (5) and a conical section that is close to the flow channel partition plate (7). The connecting section slides on the outer wall of the central cone support (5) to allow the conical section to move closer to or further away from the flow channel partition plate (7). When the conical section moves to the position furthest from the central cone support (5), the tail cone sleeve (62) fits against the front end of the flow channel partition plate (7).

4. The internal parallel combined air intake as described in claim 1, characterized in that, The adjustable lip cover (2) is cylindrical, and the outermost front end of the adjustable lip cover (2) has a transition surface with a gradually increasing outer diameter.

5. The internal parallel combined air intake as described in claim 1, characterized in that, The central cone support (5) is fixed in position, and the central cone support (5) is fixedly connected to the outer cylinder of the air intake duct (3) through several bleed support plates (4).

6. The internal parallel combined air intake as described in claim 1, characterized in that, The flow channel partition plate (7) includes three curved panels that are smoothly connected from front to back. The inner diameters of the three curved panels are all equal and remain unchanged. The outer diameter of the first curved panel remains unchanged. The outer diameter of the second curved panel gradually increases. The outer diameter of the third curved panel remains unchanged.

7. The internal parallel combined air intake as described in claim 1, characterized in that, The central cone (1), adjustable lip cover (2), and tail cone sleeve (62) all move in the direction of translation along the axial direction.

8. The internal parallel combined air intake as described in claim 1, characterized in that, The drive system includes a first motor (11) and a second motor (65) installed in the central cone support (5), a third motor (23) and a fourth motor (63) installed on the outer wall of the air intake outer cylinder (3); the output shaft of the first motor (11) is connected to the central cone (1), the output shaft of the second motor (65) is connected to the tail cone sleeve (62), the third motor (23) is connected to the adjustable lip cover (2) through the connecting rod (21), and the output shaft of the fourth motor (63) is connected to the fish scale assembly (61) through the hinge (64).

9. A control method for an internal parallel combined intake duct as described in any one of claims 1-8, characterized in that, When the aircraft speed is lower than the preset Mach number, the drive system controls the fish scale group (61) to move away from the front end of the flow channel partition plate (7) and controls the tail cone sleeve (62) to fit with the front end of the flow channel partition plate (7), closing the ram air passage (9) and opening the turbine passage (8); the drive system controls the central cone (1) to move forward to increase the throat area of ​​the air intake to reduce the internal contraction ratio of the air intake, so that the air intake meets the start-up requirements. When the flight Mach number gradually increases, the drive system controls the central cone (1) to move backward to reduce the throat area of ​​the air intake to increase the internal contraction ratio of the air intake, while controlling the adjustable lip (2) to cooperate with the movement of the compression cone shock wave to meet the air intake flow capture requirements; when the aircraft speed reaches the preset mode switching Mach number, the drive system controls the fish scale group (61) to fit with the front end of the flow channel partition plate (7) and controls the tail cone sleeve (62) to move away from the front end of the flow channel partition plate (7), closing the turbine passage (8) and opening the ram air passage (9).

10. The control method for the internal parallel combined intake duct as described in claim 9, characterized in that, The controllable lip cover (2) is used in conjunction with the movement of the compression cone shock wave as follows: when the required flow coefficient of the intake is large, the adjustable lip cover (2) is moved forward to get closer to the compression cone shock wave; when the required flow coefficient of the intake is small, the adjustable lip cover (2) is moved backward to get away from the compression cone shock wave.

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