Ramjet inlet self-adapting spill device and method

Abstract

The present application relates to ramjet engine technical field, and proposes a kind of ramjet engine inlet duct self-adapting overflow device and method, including inlet duct inner wall, lip cover and discharge component, inlet duct inner wall is equipped with discharge cavity and exhaust port, the discharge cavity is located at inlet duct not starting flow field detached shock wave, the exhaust port is located in discharge cavity, for forming discharge passage;Lip cover is fixed on inlet duct inner wall;Discharge component is arranged in discharge cavity, and it includes movable baffle and blocking slide, movable baffle is hinged on inlet duct inner wall, for blocking the opening side of discharge cavity.This ramjet engine inlet duct self-adapting overflow device and method can start overflow regulation when inlet duct is in not starting state, and does not need to rely on other energy and its control mechanism, greatly reduce energy consumption and manufacturing cost, reduce overflow device space area.

Description

Technical Field

[0001] This invention relates to the field of ramjet engine technology, and in particular to an adaptive overflow device and method for the intake duct of a ramjet engine. Background Technology

[0002] A ramjet engine is a type of air-breathing jet engine that utilizes the incoming airflow to slow it down and increase its static pressure. Ramjet engines do not have a compressor (and therefore do not require a gas turbine), so they are also called compressorless air-breathing jet engines. They typically consist of four parts: an air intake (also called a diffuser), an isolator, a combustion chamber, and a nozzle. The air intake is one of the important aerodynamic components of a supersonic air-breathing aircraft propulsion system. Its main function is to slow down and pressurize the air captured by the aircraft, providing the engine combustion chamber with an airflow that meets certain requirements for pressure, speed, and uniformity.

[0003] The starting characteristics of the air intake are one of the key factors affecting the stable operation of an aircraft. When the air intake is not running, on the one hand, the engine thrust will be reduced or even unable to work, and on the other hand, the drag of the aircraft will be increased, affecting the stability of the flight attitude.

[0004] The main method to improve the starting capability of the inlet is to use various flow control methods to improve the flow capacity and the matching of the incoming flow within the inlet. Flow control is a common method to improve the starting performance of the ramjet engine inlet. Currently, flow control includes active control methods and passive control methods. Active control methods include plasma control and magnetohydrodynamic control, jet injection control, overflow port adjustment control, etc. These control methods all rely on complex control programs, which are difficult to implement in practice and have low reliability. For example, a plasma phase change control inlet and control method is disclosed in CN104314690A. Passive control methods include boundary layer suction and eddy current generators. These methods are relatively easy to implement in engineering, but because their structure is fixed and cannot be adjusted, they cannot effectively adjust the air overflow according to the changes in the engine inlet's operating state, making it difficult to adapt to the wide operating range of ramjet engines. For example, a supersonic inlet boundary layer control device is disclosed in CN106225606B. Summary of the Invention

[0005] In view of this, the present invention proposes an adaptive overflow device and method for the intake duct of a ramjet engine.

[0006] The technical solution of this invention is implemented as follows:

[0007] On one hand, the present invention provides an adaptive overflow device for the intake duct of a ramjet engine, including an inner wall of the intake duct, a lip cover, and a bleed assembly, wherein,

[0008] An exhaust cavity and an exhaust port are provided on the inner wall of the air intake duct. The exhaust cavity is located at the point in the air intake duct where the flow field does not detach from the shock wave, and the exhaust port is located inside the exhaust cavity to form an exhaust channel.

[0009] The lip cover is installed inside the air intake and fixed to the inner wall of the air intake.

[0010] The venting assembly is disposed within the venting cavity, and includes a movable baffle and a blocking slider, wherein...

[0011] The movable baffle is hinged to the inner wall of the air intake duct and is used to block the opening side of the venting chamber;

[0012] The blocking slider is movably disposed in the venting chamber and is connected to the movable baffle in a transmission manner. The blocking slider selectively blocks the exhaust port.

[0013] When the ramjet engine intake is not in operation, the movable baffle rotates and opens towards the inside of the venting chamber, and drives the sealing slider away from the exhaust port, so that the venting chamber and the exhaust port are connected to form a venting channel.

[0014] Based on the above technical solutions, preferably, a groove is provided in the venting cavity, the sealing slider is slidably disposed in the groove, and the exhaust port is connected to the venting cavity through the groove.

[0015] Based on the above technical solutions, preferably, the venting assembly further includes a connecting rod assembly, which is disposed in the venting cavity and is connected to the movable baffle and the blocking slider in a transmission manner, so that the movable baffle and the blocking slider can move synchronously.

[0016] More preferably, the linkage assembly includes a first linkage, a second linkage, and a third linkage, wherein,

[0017] One end of the first connecting rod is hinged inside the venting cavity;

[0018] The two ends of the second link are respectively hinged to the movable baffle and the other end of the first link;

[0019] One end of the third link is hinged to the connection between the first and second links, and the other end is hinged to the sealing slider.

[0020] Based on the above technical solutions, preferably, an overflow cavity is also provided on the inner wall of the air intake duct. The overflow cavity is located on the side of the venting cavity away from the lip cover and is connected to the venting cavity.

[0021] More preferably, the inner wall of the air intake is provided with several overflow ports, which are connected to the overflow chamber to balance the internal and external air pressure of the overflow chamber.

[0022] More preferably, it also includes a built-in partition, which is fixed inside the venting cavity, and the first connecting rod is hinged to the built-in partition.

[0023] Based on the above technical solutions, preferably, it also includes an elastic element, which is disposed in the venting cavity and connected to the sealing slider, and is used to apply a thrust to the sealing slider so that it tends to seal the exhaust port.

[0024] More preferably, the elastic element is a spring.

[0025] On the other hand, the present invention provides an adaptive overflow method for the intake duct of a ramjet engine, which is based on the above-mentioned adaptive overflow device, wherein the intake duct of the ramjet engine has a non-starting state and a starting state.

[0026] When the ramjet engine intake is not in operation, a detached shock wave is formed on the outer side of the lip cover. The static pressure of the airflow in front of the detached shock wave is p1, and the static pressure of the airflow behind it is p3. The overflow chamber is connected to the front of the detached shock wave through the venting chamber. The static pressure in the overflow chamber is p2, and p3>p2. The movable baffle rotates into the overflow chamber under the action of the pressure difference on both sides, and drives the sealing slider to slide open the exhaust port, so that the overflow chamber and the exhaust port are connected to form an overflow channel. At the same time, the size of the overflow channel is changed according to the pressure difference p4=p3-p1.

[0027] When the ramjet engine intake is in the starting state, p2 = p3. The movable baffle closes the opening side of the venting chamber, and the blocking slider closes the exhaust port to reduce the overflow of the intake.

[0028] The adaptive overflow device and method for the intake duct of a ramjet engine of the present invention have the following advantages over the prior art:

[0029] (1) By setting up the bleed component, the overflow adjustment process of the intake duct relies entirely on its own mechanical structure. It can start the overflow adjustment when the intake duct is in a non-starting state and restore the overflow structure after the intake duct is restarted. It does not require the use of other energy sources and their control mechanisms, which greatly reduces energy consumption and manufacturing costs and reduces the space area of ​​the overflow device. Setting up the bleed component can make full use of the aerodynamic principle of the intake duct. That is, when the intake duct is in a non-starting state, there is a certain pressure difference before and after the detached shock wave. When the intake duct is in a starting state, the pressure inside and outside the bleed chamber is equal. This intake duct has a strong self-adaptive capability, which improves its starting characteristics and reflects the flexibility of flow adjustment. In addition, the boundary layer bleed component reduces the intake duct overflow during the process from the non-starting state to the starting state of the intake duct. Compared with the fixed boundary layer suction overflow device, it significantly improves the flow characteristics of the intake duct.

[0030] (2) By setting the linkage assembly, the movable baffle and the blocking slider can be synchronized, so that when the movable baffle rotates toward the venting cavity, the blocking slider can move toward the left. When the blocking slider is at the rightmost end of the slide, the exhaust port is closed. During the rotation of the movable baffle and the movement of the blocking slider to the left, the venting speed of the venting channel will gradually increase, thereby adaptively adjusting the venting speed of the venting channel. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the inactive state of the intake manifold of the adaptive overflow device for the ramjet engine intake manifold of the present invention.

[0033] Figure 2 for Figure 1 Enlarged schematic diagram of the structure at point A in the diagram;

[0034] Figure 3 This is a schematic diagram of the intake manifold start-up state bleed-out component of the adaptive overflow device for the ramjet engine intake manifold of the present invention.

[0035] Figure 4-7 This is a schematic diagram showing the change from the starting state to the non-starting state of the adaptive overflow device for the ramjet engine intake duct of the present invention. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] like Figure 1-7 As shown, the adaptive overflow device for the ramjet engine intake of the present invention utilizes the boundary layer suction flow control principle to separate low-energy fluid by opening an adaptive venting device on the wall surface at the root of the detached shock wave outside the intake lip. The device can adaptively control the size of the air overflow flow according to the severity of the intake's inability to start. That is, the overflow device of the present invention can automatically adjust the size of the venting channel according to the position of the detached shock wave and the air pressure before and after it, thereby improving the starting characteristics of the intake over a wide operating range. The device specifically includes an inner wall of the intake duct 1, a lip 2, and a venting assembly 3.

[0038] An exhaust cavity 101 and an exhaust port 102 are provided on the inner wall 1 of the intake duct. The exhaust cavity 101 is located at the point where the flow field in the intake duct does not detach from the shock wave. The exhaust port 102 is located inside the exhaust cavity 101 and is used to form an exhaust channel. The other end of the exhaust port 102 is connected to the outside, that is, the exhaust channel can discharge the airflow entering the exhaust cavity 101 into the outside atmosphere. Specifically, the inner wall 1 of the intake duct is composed of an external pressure section and the lower wall surface of the internal pressure section.

[0039] The lip cover 2 is fixed on the inner wall 1 of the air intake. When the air intake is not moving, a detached shock wave will be formed in front of the lip cover 2. That is, the venting cavity 101 is located in front of and below the lip cover 2. The lip cover 2 is composed of an outer cover wall and an inner pressure section upper wall. In this embodiment, it also includes an inner flow channel, which is the flow channel formed between the inner wall 1 of the air intake and the lip cover 2.

[0040] The venting assembly 3 is installed in the venting chamber 101. When the air intake is not started, the venting assembly 3 adjusts the airflow of the venting channel by controlling the opening amplitude according to the pressure difference, thereby achieving venting.

[0041] Specifically, the venting assembly 3 includes a movable baffle 31 and a blocking slider 32. The movable baffle 31 is hinged to the inner wall 1 of the intake duct and is used to block the opening side of the venting cavity 101. The blocking slider 32 is movably disposed in the venting cavity 101 and is connected to the movable baffle 31 in a transmission manner. The blocking slider 32 selectively blocks the exhaust port 102.

[0042] When the ramjet engine intake is in the starting state, the detached shock wave cannot be formed, so that the pressure difference inside and outside the vent chamber 101 is the same. The movable baffle 31 closes the opening side of the vent chamber 101, and at the same time the blocking slider 32 closes the exhaust port 102, so that the vent cannot be discharged, thereby reducing the overflow of the intake.

[0043] When the ramjet engine intake is not in operation, a detached shock wave is formed. This detached shock wave is... Figure 1 As shown by the dotted line, after the detached shock wave is formed, the air pressure behind the detached shock wave increases, which will push the movable baffle 31 to rotate and open towards the inside of the venting cavity 101. At the same time, since the movable baffle 31 is connected to the blocking slider 32, it can drive the blocking slider 32 away from the exhaust port 102, so that the venting cavity 101 and the exhaust port 102 are connected to form a venting channel. The opening degree of the movable baffle 31 is also different according to the different air pressure outside the detached shock wave, thereby changing the size of the venting channel according to different air pressure differences.

[0044] In a preferred embodiment, a groove 103 is provided in the venting cavity 101, and the blocking slider 32 is slidably disposed in the groove 103. The exhaust port 102 is connected to the venting cavity 101 through the groove 103. The groove 103 is located at the end of the exhaust port 102. The groove 103 can restrict the sliding direction of the blocking slider 32. In addition to guiding the blocking slider 32, it can also limit the range of motion of the blocking slider 32. Thus, through the transmission structure, the rotation range of the movable baffle 31 is limited, avoiding excessive rotation or the movable baffle 31 rotating towards the outside of the venting cavity 101.

[0045] In this embodiment, an elastic element 5 is also provided. The elastic element 5 is disposed in the venting cavity 101 and connected to the blocking slider 32. It is used to apply a thrust to the blocking slider 32, so that it tends to block the exhaust port 102. That is, when there is no pressure difference on both sides of the movable baffle 31, the elastic element 5 will push the blocking slider 32 to slide in the position when the air intake is in the starting state. At the same time, the movable baffle 31 gradually blocks the venting cavity 101, and the elastic element 5 stores energy through elastic deformation. It should be noted that when the movable baffle 31 is opened, the force applied to the movable baffle 31 by the pressure difference must be greater than the deformation threshold of the elastic element 5 in order to push the movable baffle 31 to rotate. This can prevent the movable baffle 31 from opening when the pressure difference is small. In this embodiment, the elastic element 5 can be selected as a spring, which stores energy through the elastic deformation of the spring. More preferably, the elastic element 5 is disposed in the slide groove 103 and is arranged along the movement direction of the blocking slider 32. One end of the elastic element 5 is fixed in the slide groove 103 and the other end is fixed to the blocking slider 32.

[0046] To achieve linkage between the blocking slider 32 and the movable baffle 31, the venting assembly 3 also includes a connecting rod assembly 33. The connecting rod assembly 33 is disposed in the venting cavity 101 and is connected to the movable baffle 31 and the blocking slider 32 in a transmission manner, so that the movable baffle 31 and the blocking slider 32 can move synchronously. Through the connecting rod assembly 33, when the movable baffle 31 rotates toward the venting cavity 101, the blocking slider 32 can move toward the left. When the blocking slider 32 is at the rightmost end of the slide groove 103, it closes the exhaust port 102. During the rotation of the movable baffle 31 and the movement of the blocking slider 32 to the left, the venting speed of the venting channel will gradually increase.

[0047] Specifically, the linkage assembly 33 includes a first linkage 331, a second linkage 332, and a third linkage 333. One end of the first linkage 331 is hinged to the venting cavity 101. Both ends of the second linkage 332 are respectively hinged to the movable baffle 31 and the other end of the first linkage 331. One end of the third linkage 333 is hinged to the connection between the first linkage 331 and the second linkage 332, and the other end is hinged to the blocking slider 32. When the movable baffle 31 rotates toward the venting cavity 101, it will press the second linkage 332. The second linkage 332 pushes the first linkage 331 to rotate downward in the venting cavity 101, causing the third linkage 333 to rotate and push the blocking slider 32 to move. It should be noted that in this embodiment, the included angles between the first linkage 331, the second linkage 332, and the third linkage 333 are all acute angles.

[0048] In order to allow the air in the overflow chamber 104 to be discharged outward and for the movable baffle 31 to be rotated, an overflow chamber 104 is also provided on the inner wall 1 of the air intake. The overflow chamber 104 is located on the side of the vent chamber 101 away from the lip cover 2 and is connected to the vent chamber 101. When the movable baffle 31 moves, the air in the vent chamber 101 can enter the overflow chamber 104, so as to avoid the air pressure in the vent chamber 101 from hindering the opening of the movable baffle 31.

[0049] Specifically, the inner wall 1 of the air intake is provided with several overflow ports 105. The overflow ports 105 are connected to the overflow chamber 104 and are used to balance the internal and external air pressure of the overflow chamber 104. The overflow ports 105 are set before the detachment shock wave of the air intake so that the air inside the overflow chamber 104 can overflow outward for the movable baffle 31 to open.

[0050] In this embodiment, an internal partition 4 is also provided. The internal partition 4 is fixed inside the discharge cavity 101. The first connecting rod 331 is hinged to the internal partition 4. The internal partition 4 can separate the overflow cavity 104 from the discharge cavity 101, and at the same time, the end of the first connecting rod 331 is hinged to the internal partition 4.

[0051] like Figure 4-7 As shown, the adaptive overflow method for the ramjet engine intake duct of the present invention is based on the above-mentioned adaptive overflow device, wherein the ramjet engine intake duct has an inactive state and an active state.

[0052] When the ramjet engine intake is not in operation, a detached shock wave is formed on the outer side of the lip cover 2. The static pressure on the front side of the detached shock wave is p1, the static pressure on the rear side is p3, and the static pressure in the overflow chamber 104 is p2. Since p3>p1 and p1=p2, p3>p2. Under the action of the pressure difference on both sides, the movable baffle 31 rotates into the overflow chamber 104 and drives the sealing slider 32 to slide open the exhaust port 102, so that the overflow chamber 104 and the exhaust port 102 are connected to form an overflow channel. At the same time, the size of the overflow channel is changed according to the pressure difference p4=p3-p1.

[0053] When the ramjet engine intake manifold changes from the off state to the on state, p2 = p3, the elastic element 5 will push the sealing slider 32 to perform a reset action, causing the movable baffle 31 to move. The movable baffle 31 will close the opening side of the venting chamber 101, and the sealing slider 32 will close the exhaust port 102 to reduce the overflow of the intake manifold.

[0054] In this embodiment, Figure 4-7 Corresponding to numbers 1)-4), where Figure 4 When the air intake is not activated, during the initial stage of shock wave formation, the movable baffle 31 has not yet activated. Figure 5-6 When the intake manifold is not in operation, p3 increases, and the movable baffle 31 gradually opens under the action of the pressure difference, while the overflow channel widens. Figure 7 When the intake duct is in the starting state, the detached shock wave disappears, and at this time p2 = p3, causing the movable baffle 31 to return to its original position.

[0055] The above description is only a preferred embodiment of the present invention and is 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 within the protection scope of the present invention.

Claims

1. An adaptive overflow device for the intake duct of a ramjet engine, characterized in that: Includes the inner wall of the intake duct (1), the lip cover (2), and the venting assembly (3), wherein, An exhaust cavity (101) and an exhaust port (102) are provided on the inner wall (1) of the air intake duct. The exhaust cavity (101) is located at the point where the air intake duct does not generate a shock wave from the detached flow field. The exhaust port (102) is located inside the exhaust cavity (101) and is used to form an exhaust channel. The lip cover (2) is set inside the air intake and fixed to the inner wall (1) of the air intake; The venting assembly (3) is disposed within the venting cavity (101), and includes a movable baffle (31) and a blocking slider (32), wherein, The movable baffle (31) is hinged to the inner wall (1) of the air intake duct and is used to block the opening side of the venting chamber (101); The blocking slider (32) is movably disposed in the venting chamber (101) and is connected to the movable baffle (31) in a transmission manner. The blocking slider (32) selectively blocks the exhaust port (102). When the ramjet engine intake is not in operation, the movable baffle (31) rotates and opens towards the inside of the venting chamber (101), and drives the blocking slider (32) away from the exhaust port (102), so that the venting chamber (101) and the exhaust port (102) are connected to form a venting channel; The venting cavity (101) is provided with a sliding groove (103), the blocking slider (32) is slidably disposed in the sliding groove (103), and the exhaust port (102) is connected to the venting cavity (101) through the sliding groove (103); The venting assembly (3) also includes a connecting rod assembly (33), which is disposed in the venting cavity (101) and is connected to the movable baffle (31) and the blocking slider (32) in a transmission manner, so that the movable baffle (31) and the blocking slider (32) can move synchronously; The linkage assembly (33) includes a first link (331), a second link (332), and a third link (333), wherein, One end of the first connecting rod (331) is hinged to the venting chamber (101); The two ends of the second link (332) are respectively hinged to the movable baffle (31) and the other end of the first link (331); One end of the third link (333) is hinged to the connection between the first link (331) and the second link (332), and the other end is hinged to the blocking slider (32).

2. The adaptive overflow device for the ramjet engine intake as described in claim 1, characterized in that: An overflow cavity (104) is also provided on the inner wall (1) of the air intake. The overflow cavity (104) is located on the side of the vent cavity (101) away from the lip cover (2) and is connected to the vent cavity (101).

3. The adaptive overflow device for the ramjet engine intake as described in claim 2, characterized in that: The inner wall (1) of the air intake is also provided with several overflow ports (105), which are connected to the overflow chamber (104) to balance the internal and external air pressure of the overflow chamber (104).

4. The adaptive overflow device for the ramjet engine intake as described in claim 1, characterized in that: It also includes a built-in partition (4), which is fixed inside the venting cavity (101), and the first connecting rod (331) is hinged to the built-in partition (4).

5. The adaptive overflow device for the ramjet engine intake as described in claim 1, characterized in that: It also includes an elastic element (5), which is disposed in the venting cavity (101) and connected to the blocking slider (32) for applying a thrust to the blocking slider (32) so that it tends to block the exhaust port (102).

6. The adaptive overflow device for the ramjet engine intake as described in claim 5, characterized in that: The elastic element (5) is a spring.

7. An adaptive overflow method for the intake duct of a ramjet engine, characterized in that: Based on the adaptive overflow device according to any one of claims 1-6, the ramjet engine intake has a non-starting state and a starting state; When the ramjet engine intake is not in operation, a detached shock wave is formed on the outside of the lip cover (2). The static pressure of the airflow in front of the detached shock wave is p1, and the static pressure of the airflow behind it is p3. The overflow chamber (104) is connected to the front of the detached shock wave through the vent chamber (101). The static pressure in the overflow chamber (104) is p2, and p3>p2. The movable baffle (31) rotates into the overflow chamber (104) under the action of the pressure difference on both sides, and drives the sealing slider (32) to slide open the exhaust port (102), so that the overflow chamber (104) and the exhaust port (102) are connected to form an overflow channel. At the same time, the size of the overflow channel is changed according to the pressure difference p4=p3-p1. When the ramjet engine intake is in the starting state, p2=p3, the movable baffle (31) closes the opening side of the venting chamber (101), and the blocking slider (32) closes the exhaust port (102) to reduce the overflow of the intake.

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