A single-sided expansion nozzle based on hydrogen injection and entrainment

Abstract

The present application provides a single-sided expansion nozzle based on hydrogen injection and entrainment, belonging to the technical field of nozzles for hypersonic aircraft. It includes an entrainment channel and a main flow channel. Fixed walls, an entrainment channel wall, and an entrainment adjustment plate movably connected to the entrainment channel wall are provided on both sides of the entrainment channel. The entrainment adjustment plate is located at the front end of the entrainment channel wall along the airflow direction. On one side of the main flow channel, a converging section wall and a diverging section wall are fixedly connected, and the diverging section wall is also fixedly connected to the front end of the entrainment channel wall. On the other side of the main flow channel, a converging adjustment plate and a diverging adjustment plate are movably connected. The converging section wall and the converging adjustment plate are arranged opposite to each other to form the converging section of the main flow channel, and the diverging section wall and the diverging adjustment plate are arranged opposite to each other to form the diverging section of the main flow channel. A hydrogen injection hole is provided near the throat of the converging section, and the hydrogen injection hole is located on the converging section wall. Through the processing solution of the present application, the effect of over-expansion can be alleviated, and the performance of the single-sided expansion nozzle is improved.

Description

Technical Field

[0001] The present application relates to the technical field of hypersonic aircraft nozzles, and in particular to a unilateral expansion nozzle based on hydrogen injection and ejection. Background Art

[0002] The nozzle is the exhaust device of the aircraft engine. The high-temperature combustion gas expands and performs work in the nozzle, generating thrust.

[0003] Hypersonic vehicles have a wide flight envelope, requiring an integrated design of the vehicle, propulsion system, and tail nozzle. Single-sided expansion nozzles, which directly utilize the lower surface of the vehicle's rear body as the external expansion surface, can operate under pressure drop ratios of several hundred to several thousand, achieving an area expansion ratio of several dozen. Because of their integration with the vehicle, they can effectively reduce rear body drag, and have been verified in the US X-43 and X-51 hypersonic drones. However, single-sided expansion nozzles are severely overexpanded when not in their design point, and may even experience flow separation. This is accompanied by the interaction of complex phenomena such as shock waves, expansion waves, and interference between shock wave boundary layers, resulting in a severe performance degradation and potentially drastic changes in nozzle thrust and lift. Summary of the Invention

[0004] In view of this, an embodiment of the present application provides a single-sided expansion nozzle based on hydrogen injection, which at least partially solves the problem in the prior art that the single-sided expansion nozzle is in a serious over-expansion state when not in the design point state, resulting in a serious decline in nozzle performance.

[0005] An embodiment of the present application provides a unilateral expansion nozzle based on hydrogen injection and ejection, comprising an ejection channel and a mainstream channel. Fixed walls, ejection channel walls, and ejection adjustment plates movably connected to the ejection channel walls are provided on both sides of the ejection channel. The ejection adjustment plate is located at the front end of the ejection channel wall along the airflow direction. A fixedly connected convergent section wall and an expansion section wall are provided on one side of the mainstream channel. The expansion section wall is also fixedly connected to the front end of the ejection channel wall along the airflow direction. A movably connected convergent adjustment plate and an expansion adjustment plate are provided on the other side of the mainstream channel. The convergent section wall and the convergent adjustment plate are arranged relative to each other and constitute the convergent section of the mainstream channel. The expansion section wall and the expansion adjustment plate are arranged relative to each other and constitute the expansion section of the mainstream channel. A hydrogen injection hole for injecting hydrogen into the throat of the mainstream channel is provided near the throat of the convergent section, and the hydrogen injection hole is located on the convergent section wall.

[0006] According to a specific implementation of the embodiment of the present application, the central axis of the hydrogen injection hole is perpendicular to the horizontal plane of the wall of the convergent section.

[0007] According to a specific implementation of the embodiment of the present application, the ratio of the pressure of the hydrogen injected into the hydrogen injection hole to the ambient pressure is in the range of 1 to 2.

[0008] According to a specific implementation mode of an embodiment of the present application, the nozzle further includes a driven mechanism and a driving mechanism. The driven mechanism includes a first driven mechanism, a second driven mechanism, and a third driven mechanism. The driving mechanism includes a first driving mechanism, a second driving mechanism, and a third driving mechanism. The convergent adjustment plate is connected to the first driven mechanism through a rotating pair. The divergent adjustment plate is connected to the second driven mechanism through a rotating pair. The ejector adjustment plate is connected to the third driven mechanism through a rotating pair. The first driven mechanism is connected to the first driving mechanism through a rotating pair. The second driven mechanism is connected to the second driving mechanism through a rotating pair. The third driven mechanism is connected to the third driving mechanism through a rotating pair. The first driving mechanism, the second driving mechanism, and the third driving mechanism are respectively connected to the fixed casing of the nozzle through a sliding pair.

[0009] According to a specific implementation mode of an embodiment of the present application, the angle adjustment range of the convergent adjustment plate is 0° to 40°, the angle adjustment range of the divergent adjustment plate is 0° to 30°, and the angle adjustment range of the ejector adjustment plate is 0° to 20°.

[0010] According to a specific implementation mode of an embodiment of the present application, when the working state of the nozzle is the large area ratio state, the first driving mechanism drives the first driven mechanism to extend outwards, the second driving mechanism drives the second driven mechanism to contract inwards, and the convergent adjustment plate and the divergent adjustment plate rotate around the hinge point to reach the large area ratio state.

[0011] According to a specific implementation mode of an embodiment of the present application, when the working state of the nozzle is the small area ratio state, the first driving mechanism drives the first driven mechanism to contract inwards, the second driving mechanism drives the second driven mechanism to extend outwards, and the convergent adjustment plate and the divergent adjustment plate rotate around the hinge point to reach the small area ratio state.

[0012] According to a specific implementation mode of an embodiment of the present application, when the working state of the nozzle is the ejector open state, the third driving mechanism drives the third driven mechanism to extend outwards, and the ejector adjustment plate rotates around the hinge point to reach the ejector channel open state.

[0013] According to a specific implementation mode of an embodiment of the present application, when the working state of the nozzle is the hydrogen injection state, in the ejector open state, by increasing the flow rate of the injected hydrogen, the airflow in the mainstream channel is restricted, the pressure in the divergent section is reduced, and the secondary flow in the ejector channel is ejected through the pressure difference.

[0014] According to a specific implementation mode of an embodiment of the present application, there are multiple hydrogen injection holes, and the multiple hydrogen injection holes are evenly distributed on the convergent section wall surface along the direction perpendicular to the airflow.

[0015] Beneficial effects:

[0016] In the unilateral expansion nozzle based on hydrogen injection and entrainment in the embodiments of the present application, the entrainment function is added. The secondary flow in the entrainment channel acts as an air cushion on the main flow path, restricting the expansion of the main flow. The entrainment adjustment plate is movably connected and can be rotationally adjusted relative to the wall surface of the entrainment channel, thereby realizing the flow rate adjustment of the secondary flow in the entrainment channel. By adjusting the flow rate of the secondary flow, the flow area of the main flow path can be controlled to reach or approach complete expansion, reducing thrust loss and enabling the aircraft to have good performance within a wide range. In addition, a hydrogen injection function is added in this embodiment. The main flow is affected by hydrogen, causing the throat area to change. At the same time, the secondary flow is entrained through the pressure difference, achieving the effect of alleviating over-expansion and further improving the performance of the unilateral expansion nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 Schematic diagram of the mechanical structure of the unilateral expansion nozzle based on hydrogen injection and entrainment according to an embodiment of the present invention;

[0019] Figure 2 Schematic diagram of the fluid flow of the unilateral expansion nozzle based on hydrogen injection and entrainment according to an embodiment of the present invention;

[0020] Figure 3 Simplified diagram of the motion mechanism of the unilateral expansion nozzle based on hydrogen injection and entrainment according to an embodiment of the present invention;

[0021] Figure 4 Schematic diagram of the large area ratio state of the unilateral expansion nozzle based on hydrogen injection and entrainment according to an embodiment of the present invention, (a) is the simplified diagram of the motion mechanism, and (b) is the mechanical structure diagram;

[0022] Figure 5 Schematic diagram of the small area ratio state of the unilateral expansion nozzle based on hydrogen injection and entrainment according to an embodiment of the present invention, (a) is the simplified diagram of the motion mechanism, and (b) is the mechanical structure diagram;

[0023] Figure 6 Schematic diagram of the entrainment opening state of the unilateral expansion nozzle based on hydrogen injection and entrainment according to an embodiment of the present invention, (a) is the simplified diagram of the motion mechanism, and (b) is the mechanical structure diagram.

[0024] In the figure: 1. First driving mechanism; 2. First driven mechanism; 3. First actuating mechanism; 4. Second driving mechanism; 5. Second driven mechanism; 6. Second actuating mechanism; 7. Third driving mechanism; 8. Third driven mechanism; 9. Third actuating mechanism; 10. Ejector regulating plate; 11. Fixed wall surface; 12. Ejector channel wall surface; 13. Converging section wall surface; 14. Hydrogen injection hole; 15, Convergence regulating plate; 16. Divergence regulating plate; 17. Diverging section wall surface. Detailed implementation mode

[0025] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0026] The following uses specific specific examples to illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0027] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, this device and / or practice this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0028] It should also be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. The drawings only show the components related to the present application, rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in its actual implementation can be an arbitrary change, and the component layout type may also be more complex.

[0029] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0030] An embodiment of the present application provides a single-sided expansion nozzle based on hydrogen injection and entrainment, which will be described in detail below with reference to Figures 1 to 6 for a detailed description.

[0031] Referring to Figure 1 , an embodiment of the present application provides a single-sided expansion nozzle based on hydrogen injection and entrainment, including an entrainment channel and a main flow channel. Fixed walls 11, entrainment channel walls 12 are provided on both sides of the entrainment channel, and an entrainment adjustment plate 10 movably connected to the entrainment channel wall 12. The entrainment adjustment plate 10 is located at the front end of the entrainment channel wall 12 along the air flow direction. A converging section wall 13 and a diverging section wall 17 are fixedly connected to one side of the main flow channel. The diverging section wall 17 is also fixedly connected to the front end of the entrainment channel wall 12 along the air flow direction. A converging adjustment plate 15 and a diverging adjustment plate 16 are movably connected to the other side of the main flow channel. The converging section wall 13 and the converging adjustment plate 15 are oppositely arranged to form the converging section of the main flow channel, and the diverging section wall 17 and the diverging adjustment plate 16 are oppositely arranged to form the diverging section of the main flow channel; a hydrogen injection hole 14 for injecting hydrogen into the throat of the main flow channel is provided near the throat of the converging section, and the hydrogen injection hole 14 is located on the converging section wall 13.

[0032] Referring to Figure 2 , the single-sided expansion nozzle in this embodiment increases the entrainment function. The secondary flow in the entrainment channel acts as an air cushion on the main flow path, restricting the expansion of the main flow. The entrainment adjustment plate 10 is movably connected and can be rotationally adjusted relative to the entrainment channel wall 12, so as to realize the flow rate adjustment of the secondary flow in the entrainment channel. By adjusting the secondary flow rate, the flow area of the main flow path can be controlled to reach or approach complete expansion, reduce thrust loss, and enable the aircraft to have good performance in a wide range. In addition, a hydrogen injection function is added in this embodiment. The main flow is affected by hydrogen, resulting in a change in the throat area. At the same time, the secondary flow is entrained through the pressure difference, achieving the effect of alleviating over-expansion and further improving the performance of the single-sided expansion nozzle.

[0033] In one embodiment, the central axis of the hydrogen injection hole 14 is perpendicular to the horizontal plane of the converging section wall 13.

[0034] In one embodiment, the ratio range of the pressure of the hydrogen injected into the hydrogen injection hole 14 to the ambient pressure is 1-2.

[0035] During specific implementation, hydrogen is injected by opening a hole at the throat. The main flow is affected by hydrogen, resulting in a change in the throat area. At the same time, the secondary flow is entrained through the pressure difference, achieving the effect of alleviating over-expansion, thereby improving the performance of the nozzle.

[0036] In one embodiment, in order to adjust the physical throat area and control the opening and closing of the ejector passage, the nozzle further includes a driven mechanism and a driving mechanism. Referring to Figure 3 , the driven mechanism includes a first driven mechanism 2, a second driven mechanism 5, and a third driven mechanism 8. The driving mechanism includes a first driving mechanism 1, a second driving mechanism 4, and a third driving mechanism 7. The convergent adjustment plate 15 is connected to the first driven mechanism 2 through a revolute pair. The divergent adjustment plate 16 is connected to the second driven mechanism 5 through a revolute pair. The ejector adjustment plate 10 is connected to the third driven mechanism 8 through a revolute pair. The first driven mechanism 2 is connected to the first driving mechanism 1 through a revolute pair. The second driven mechanism 5 is connected to the second driving mechanism 4 through a revolute pair. The third driven mechanism 8 is connected to the third driving mechanism 7 through a revolute pair. The first driving mechanism 1, the second driving mechanism 4, and the third driving mechanism 7 are respectively connected to the fixed casing of the nozzle through a prismatic pair.

[0037] The kinematic mechanism diagram of the single-sided expansion nozzle in this embodiment is as shown in Figure 3 . Its overall motion mode is a planar multi-link mechanism. Among them, the first driving mechanism 1, the second driving mechanism 4, and the third driving mechanism 7 in the form of connecting rods are respectively connected to the fixed casing through a prismatic pair and perform translational telescopic motion relative to the casing. One end of the first driven mechanism 2, the second driven mechanism 5, and the third driven mechanism 8 in the form of connecting rods are respectively connected to their corresponding driving mechanisms through a revolute pair, and the other ends are respectively connected to their corresponding actuating mechanisms through a revolute pair. Among them, the actuating mechanisms include a first actuating mechanism 3, a second actuating mechanism 6, and a third actuating mechanism 9. The first actuating mechanism 3 corresponds to the convergent adjustment plate 15, the second actuating mechanism 6 corresponds to the divergent adjustment plate 16, and the third actuating mechanism 9 corresponds to the ejector adjustment plate 10. The first actuating mechanism 3, the second actuating mechanism 6, and the third actuating mechanism 9 in the form of connecting rods are respectively connected to their corresponding driven mechanisms through a revolute pair. Therefore, this kinematic mechanism includes a total of 9 connecting rods.

[0038] Each connecting rod is connected through a revolute pair, and the driving mechanism is connected to the casing through a prismatic pair. This planar multi-link mechanism has 9 revolute pairs and 3 prismatic pairs.

[0039] Through the above analysis, it can be obtained that this mechanism has 9 connecting rods and 12 lower pairs (including 9 revolute pairs and 3 prismatic pairs). Therefore, the degree of freedom F of this mechanism is:

[0040] F = 3n - 2PL = 3 * 9 - 2 * 12 = 3,

[0041] where n is the number of connecting rods and PL is the number of lower pairs.

[0042] Therefore, the degree of freedom of the planar linkage mechanism being 3 means that the mechanism requires 3 driving mechanisms to achieve a definite motion form, which is consistent with the number of 3 linkages of the first driving mechanism 1, the second driving mechanism 4, and the third driving mechanism 7 determined during the design, indicating that the mechanism is reasonably designed and reliable.

[0043] In one embodiment, the physical throat area is adjusted by an adjusting mechanism. The angle adjustment range of the convergent adjusting plate 15 is 0° to 40°, and the angle adjustment range of the divergent adjusting plate 16 is 0° to 30°. The ejector adjusting plate 10 controls the opening and closing of the ejector passage, and the angle adjustment range of the ejector adjusting plate 10 is 0° to 20°.

[0044] The following describes in detail different working modes of the single-sided expansion nozzle based on hydrogen injection and ejection.

[0045] In one embodiment, referring to Figure 4 in (a) and (b) thereof, when the nozzle working state is in the large area ratio state, the first driving mechanism 1 drives the first driven mechanism 2 to extend outwards, the second driving mechanism 4 drives the second driven mechanism 5 to contract inwards, and the convergent adjusting plate 15 and the divergent adjusting plate 16 rotate around the hinge point to reach the large area ratio state.

[0046] In one embodiment, referring to Figure 5 in (a) and (b) thereof, when the nozzle working state is in the small area ratio state, the first driving mechanism 1 drives the first driven mechanism 2 to contract inwards, the second driving mechanism 4 drives the second driven mechanism 5 to extend outwards, and the convergent adjusting plate 15 and the divergent adjusting plate 16 rotate around the hinge point to reach the small area ratio state.

[0047] In one embodiment, referring to Figure 6 in (a) and (b) thereof, when the nozzle working state is in the ejection opening state, the third driving mechanism 7 drives the third driven mechanism 8 to extend outwards, and the ejector adjusting plate 10 rotates around the hinge point to reach the ejector passage opening state.

[0048] In one embodiment, when the nozzle working state is in the hydrogen injection state, in the ejection opening state, by increasing the flow rate of the injected hydrogen, the airflow in the main flow passage is restricted, the pressure in the divergent section is reduced, and the secondary flow in the ejector passage is ejected through the pressure difference.

[0049] In one embodiment, there are multiple hydrogen injection holes 14, and the multiple hydrogen injection holes 14 are evenly distributed on the convergent section wall surface 13 in a direction perpendicular to the airflow.

[0050] The embodiments provided by the present invention add an ejector function. The secondary flow in the ejector channel acts as an air cushion on the main flow path, restricting the expansion of the main flow. The ejector adjustment plate 10 is movably connected and can be rotationally adjusted relative to the wall surface 12 of the ejector channel, thereby realizing the flow rate adjustment of the secondary flow in the ejector channel. By adjusting the secondary flow rate, the flow area of the main flow path can be controlled to reach or approach complete expansion, reducing thrust loss and enabling the aircraft to have good performance within a wide range. In addition, a hydrogen injection function is also added in this embodiment. The main flow is affected by hydrogen, resulting in a change in the throat area. At the same time, the secondary flow is ejected through the pressure difference to achieve the effect of alleviating over-expansion and further improving the performance of the single-sided expansion nozzle.

[0051] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A unilateral expansion nozzle based on hydrogen injection, characterized in that: The invention comprises an ejection channel and a main flow channel, wherein fixed walls (11), ejection channel walls (12) and ejection adjustment plates (10) movably connected to the ejection channel walls (12) are provided on both sides of the ejection channel, the ejection adjustment plates (10) being located at the front end of the ejection channel walls (12) along the airflow direction, a fixedly connected convergent section wall (13) and an expansion section wall (17) are provided on one side of the main flow channel, the expansion section wall (17) being also fixedly connected to the front end of the ejection channel walls (12) along the airflow direction, and a movably connected convergent adjustment plate (15) and an expansion adjustment plate (16) are provided on the other side of the main flow channel. The convergent section wall (13) and the convergent regulating plate (15) are arranged relative to each other and constitute the convergent section of the mainstream channel, and the expansion section wall (17) and the expansion regulating plate (16) are arranged relative to each other and constitute the expansion section of the mainstream channel; a hydrogen injection hole (14) for injecting hydrogen into the throat of the mainstream channel is provided near the throat of the convergent section, and the hydrogen injection hole (14) is located on the convergent section wall (13), and the central axis of the hydrogen injection hole (14) is perpendicular to the horizontal plane of the convergent section wall (13). The mainstream is affected by hydrogen to change the throat area, and at the same time, the secondary flow in the injection channel is ejected by the pressure difference to alleviate over-expansion.

2. The unilateral expansion nozzle based on hydrogen injection and entrainment according to claim 1, characterized in that, The ratio of the pressure of the hydrogen gas injected into the hydrogen injection hole (14) to the ambient pressure is in the range of 1 to 2.

3. The unilateral expansion nozzle based on hydrogen injection and entrainment according to claim 1, characterized in that, The nozzle further comprises a driven mechanism and a driving mechanism, wherein the driven mechanism comprises a first driven mechanism (2), a second driven mechanism (5) and a third driven mechanism (8), and the driving mechanism comprises a first driving mechanism (1), a second driving mechanism (4) and a third driving mechanism (7). The convergence adjustment plate (15) is connected to the first driven mechanism (2) through a rotating pair, the expansion adjustment plate (16) is connected to the second driven mechanism (5) through a rotating pair, and the ejection adjustment plate (10) is connected to the third driven mechanism (8) through a rotating pair. The first driven mechanism (2) is connected to the first driving mechanism (1) through a rotating pair, the second driven mechanism (5) is connected to the second driving mechanism (4) through a rotating pair, and the third driven mechanism (8) is connected to the third driving mechanism (7) through a rotating pair. The first driving mechanism (1), the second driving mechanism (4) and the third driving mechanism (7) are respectively connected to the fixed casing of the nozzle through a moving pair.

4. The unilateral expansion nozzle based on hydrogen injection and entrainment according to claim 3, characterized in that The angle adjustment range of the convergence adjustment plate (15) is 0°~40°, the angle adjustment range of the expansion adjustment plate (16) is 0°~30°, and the angle adjustment range of the ejection adjustment plate (10) is 0°~20°.

5. The unilateral expansion nozzle based on hydrogen injection and entrainment according to claim 3, characterized in that, When the nozzle is in a large area ratio state, the first drive mechanism (1) drives the first driven mechanism (2) to extend outward, the second drive mechanism (4) drives the second driven mechanism (5) to retract inward, and the convergence adjustment plate (15) and the expansion adjustment plate (16) rotate around the hinge point to achieve a large area ratio state.

6. The unilateral expansion nozzle based on hydrogen injection and entrainment according to claim 3, characterized in that When the nozzle is in a small area ratio state, the first drive mechanism (1) drives the first driven mechanism (2) to retract inward, the second drive mechanism (4) drives the second driven mechanism (5) to extend outward, and the convergence adjustment plate (15) and the expansion adjustment plate (16) rotate around the hinge point to achieve a small area ratio state.

7. The single-sided expansion nozzle based on hydrogen injection and entrainment according to claim 3, wherein When the nozzle is in the ejection opening state, the third driving mechanism (7) drives the third driven mechanism (8) to extend outward, and the ejection adjustment plate (10) rotates around the hinge point to achieve the ejection channel opening state.

8. The unilateral expansion nozzle based on hydrogen injection and entrainment according to claim 7, characterized in that, When the nozzle is in the hydrogen injection state, in the ejection open state, the flow of injected hydrogen is increased to limit the airflow in the mainstream channel, reduce the expansion section pressure, and eject the secondary flow in the ejection channel through the pressure difference.

9. The unilateral expansion nozzle based on hydrogen injection and ejector according to any one of claims 1-8, characterized in that A plurality of hydrogen injection holes (14) are provided, and the plurality of hydrogen injection holes (14) are evenly distributed on the convergent section wall surface (13) along a direction perpendicular to the airflow.

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