Duct switching device suitable for serial TBCC mode conversion and control method thereof

Abstract

The embodiment of the invention provides a duct switching device suitable for serial TBCC mode conversion and a control method of the duct switching device, and relates to the technical field of pneumatic engines. The duct switching device comprises an outer casing, an inner casing and an inner casing, the sealing cover is communicated with an air outlet of the air inlet channel; the center body is arranged in the air inlet channel; the central body comprises a central cone and a straight-wall cylinder body, and the central cone is connected with the straight-wall cylinder body; an annular channel formed between the straight wall cylinder and the outer casing is an air inlet channel throat. According to the duct switching device suitable for serial TBCC mode conversion and the control method of the duct switching device, the variable geometry lobes and the translation center sleeve are adopted to synchronously adjust the channel flow distribution proportion in the mode conversion process, and the mode conversion function is achieved; continuous adjustment of the air flow can be achieved in the conventional through-flow state and the mode switching process, and the problem that thrust suddenly changes during mode switching of a traditional TBCC is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air-driven engine, in particular to a duct switching device suitable for serial TBCC mode conversion and a control method thereof. BACKGROUND

[0002] The rapid, low-cost and long-distance rapid strike of space carriers to targets around the world makes the demand for long-range, high-speed aircraft by countries around the world grow rapidly, and the key to achieving high-speed long-distance flight is the propulsion system. The hypersonic aircraft can adopt multiple combined power forms such as turbine engines, rocket engines and ramjet engines, among which the turbine-based combined cycle engine (TBCC) that meets the requirements of high specific impulse in the full speed range, uses carbon-hydrogen fuel, and is reusable, has become a popular direction in the current domestic engine research field. The aircraft using TBCC engine has high-speed performance and the operating advantages of conventional aircraft, can realize horizontal take-off and landing, and has high durability, reusability and large thrust characteristics. Compared with other power forms, TBCC has higher specific impulse at low speed, lower operating cost, and excellent safety and stability, making it an ideal power choice for future hypersonic flight. Therefore, in-depth research on TBCC propulsion system has important strategic significance. In this system, smooth conversion between turbine mode and ram mode is a key technical difficulty that needs to be broken through in the development of TBCC.

[0003] The mode conversion system of the serial TBCC engine is a key transition section connecting the inlet and the engine, which must use a short-distance, low-loss variable geometry structure design to meet the flow demand of different engines in operation, and to study the flow characteristics of the mode conversion process. When the turbine mode and the ram mode are converted to each other, not only does the inlet need to provide sufficient airflow of good quality to the turbine / ram engine, but also the flow and thrust of the propulsion system need to be smoothly transitioned. In order to make the TBCC engine work efficiently in a wide range of conditions, it is necessary to develop a variable geometry inlet and a low-loss mode conversion system that matches the TBCC engine. In the serial layout, the ramjet engine and the turbofan engine share the inlet, the afterburner / ramjet combustion chamber and the nozzle, and the mode conversion process is adjusted and controlled by mode selection valves and other flow dividing devices. Although it has the advantages of compact structure and small frontal area brought by turbine / ram combined power, it also faces the challenges of complex control and difficult development. According to the working state of the turbine passage in the conversion process, the mode conversion system can be divided into two typical modes of "turbine windmill state" and "turbine passage closed".

[0004] The mainstream design scheme of the current series TBCC mode conversion device mainly adopts the "mode selection valve + movable center cone" configuration, but this configuration has significant technical bottlenecks: the profile design is difficult to effectively isolate the separation vortex generated by the main flow and the back of the lobe, resulting in serious flow field distortion, obvious flow separation and high aerodynamic loss level; secondly, the movable center cone needs to move forward and backward as a whole, not only occupies a large space due to the installation of the actuator at the rear of the center cone (the front end of the turbine engine), affecting the layout of the turbine engine, but also has the problem of poor design point performance, which is difficult to meet the stealth requirements of the turbine engine and cannot realize high-performance mode conversion. These limitations make the TBCC mode conversion device face the problem of flow field optimization under the design point working condition of the pure turbine channel, the pure ramjet channel and the intermediate transition state of the non-design point working condition. SUMMARY

[0005] In order to solve the technical problem that the existing series TBCC mode conversion device faces the problem of flow field optimization under the design point working condition of the pure turbine channel, the pure ramjet channel and the intermediate transition state of the non-design point working condition, the embodiments of the present application provide a duct switching device suitable for series TBCC mode conversion and a control method thereof. The technical scheme is as follows:

[0006] The present application provides a duct switching device suitable for series TBCC mode conversion, comprising:

[0007] An outer casing in the shape of a cylinder, the outer casing having an air inlet;

[0008] A sealing cover in communication with the air outlet of the air inlet;

[0009] A center body arranged in the air inlet; the center body comprises a center cone and a straight wall cylinder, the center cone being connected with the straight wall cylinder; an annular passage formed between the straight wall cylinder and the outer casing is an air inlet throat;

[0010] A translation center sleeve arranged in the sealing cover; the translation center sleeve is supported to move in the axial direction of the sealing cover; the translation center sleeve comprises a connecting straight section and a contraction section, the connecting straight section being connected with the contraction section; the connecting straight section is slidably sleeved on the straight wall cylinder;

[0011] An intermediate casing in the shape of a cylinder; the intermediate casing separates the annular passage between the sealing cover and the translation center sleeve into an inner duct and an outer duct;

[0012] A plurality of variable geometry lobes arranged around the air outlet of the air inlet; the first end of the variable geometry lobe is rotationally connected with the air outlet of the air inlet in the axial direction of the outer casing;

[0013] When the two ends of the connecting straight section are connected with the intermediate casing and the straight wall cylinder respectively, and the variable geometry vane rotates to the side away from the intermediate casing, an annular channel between the variable geometry vane and the connecting straight section, the inlet passage throat and the outer duct form a ramjet channel, and the duct switching device is in a ramjet mode.

[0014] When the maximum diameter port of the convergent section is connected with the straight wall cylinder, and the variable geometry vane rotates to be connected with the intermediate casing, an annular channel between the variable geometry vane and the convergent section, the inlet passage throat and the inner duct form a turbine channel, and the duct switching device is in a turbine mode.

[0015] Optionally, the duct switching device further comprises an angle adjusting device; the variable geometry vane adjusts the rotation angle through the angle adjusting device.

[0016] The angle adjusting device comprises an actuating device, a synchronous ring and a transmission mechanism.

[0017] The actuating device and the synchronous ring are both arranged outside the outer casing; the actuating device drives the synchronous ring to move along the axis direction of the outer casing.

[0018] The synchronous ring transmits the driving force to the variable geometry vane through the transmission mechanism, and the variable geometry vane rotates around the axis direction of the outer casing under the action of the driving force.

[0019] Optionally, the transmission mechanism comprises a sliding rod, a connecting rod and a hinge mechanism.

[0020] The first end of the connecting rod is connected with the second end of the variable geometry vane through the hinge mechanism; the first end of the sliding rod is fixedly connected with the synchronous ring, and the second end of the sliding rod is connected with the second end of the connecting rod through the hinge mechanism and through the movable hole on the sealing cover.

[0021] Optionally, a sealing cover is sleeved on the sliding rod, and the sealing cover is used for sealing the movable hole.

[0022] Optionally, the rotation angle range of the variable geometry vane is 0°-44°.

[0023] Optionally, the duct switching device further comprises a plurality of vane support plates; the vane support plates are arranged around the air outlet of the inlet passage, the two ends of the vane support plates are fixedly connected with the outer casing and the intermediate casing respectively; one variable geometry vane is arranged between any two adjacent vane support plates, and the two sides of the variable geometry vane are connected with the adjacent vane support plates respectively.

[0024] Optionally, the width of the wave lobe branch plate gradually increases from the center of the cross section of the outer casing.

[0025] Optionally, the variable geometry wave lobe comprises a plane section and an arc section; the arc section is connected with the plane section, and the plane section is rotationally connected with the outer casing; the radius of the arc section is greater than or equal to 200 mm.

[0026] Optionally, the bypass switching device further comprises a hydraulic actuator;

[0027] The inner wall of the conical surface of the center cone, the inner wall of the straight wall sleeve and the inner wall of the translation center sleeve surround to form a cavity;

[0028] The hydraulic actuator is arranged in the cavity; the fixed end of the hydraulic actuator is fixed to the inner wall of the conical surface of the center cone, and the driving end of the hydraulic actuator is connected to the inner wall of the translation center sleeve; the translation center sleeve is driven by the hydraulic actuator.

[0029] The embodiment of the application further provides a control method of the bypass switching device suitable for serial TBCC mode conversion, which utilizes the bypass switching device suitable for serial TBCC mode conversion, and the control method comprises the following steps:

[0030] Turbine mode to ram mode conversion: rotating the variable geometry wave lobe to the side away from the intermediate casing, opening the ram channel, connecting the two ends of the straight section with the intermediate casing and the straight wall cylinder respectively, closing the turbine channel, and the bypass switching device is in the ram mode;

[0031] Ram mode to turbine mode conversion: connecting the maximum diameter port of the contraction section with the straight wall cylinder, opening the turbine channel, rotating the variable geometry wave lobe to be connected with the intermediate casing, closing the ram channel, and the bypass switching device is in the turbine mode.

[0032] The technical scheme provided by the embodiment of the application has at least the following beneficial effects:

[0033] The duct switching device suitable for serial TBCC mode conversion and the control method thereof provided by the embodiment of the present application, through the intermediate casing, the airflow channel is divided into the ram outer duct and the turbine inner duct, and through the coordinated action of the forward and backward movement of the translation center sleeve and the upward and downward deflection of the variable geometry sector, the continuous adjustment of the duct ratio is realized, so that the smooth transition of the engine thrust between the turbine mode and the ram mode is completed, and the thrust fluctuation caused by airflow mutation is avoided; when the translation center sleeve moves backward to the limit position and completely connects with the intermediate casing, the turbine channel can be completely closed, and when the variable geometry sector is deflected downward to completely connect with the intermediate casing, the ram channel is completely closed; the device uses the variable geometry sector and the translation center sleeve to synchronously adjust the channel flow distribution ratio in the mode conversion process, realizes the mode conversion function, and can realize the continuous adjustment of the airflow in the through-flow state of the pure turbine channel, the pure ram channel and the intermediate transition state of the mode switching, optimizes the flow field, avoids the serious flow field distortion and the flow separation phenomenon, reduces the aerodynamic loss, and solves the thrust mutation problem existing in the traditional TBCC mode switching. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0035] Figure 1 is a structural schematic diagram of a duct switching device suitable for serial TBCC mode conversion provided by the embodiment of the present application;

[0036] Figure 2 is a local structural schematic diagram of a duct switching device suitable for serial TBCC mode conversion provided by the embodiment of the present application;

[0037] Figure 3 is a structural schematic diagram of the variable geometry sector in the zero opening state and the translation center sleeve in the fully open state;

[0038] Figure 4 is a structural schematic diagram of the variable geometry sector in the maximum opening state and the translation center sleeve in the fully open state;

[0039] Figure 5 is a structural schematic diagram of the variable geometry sector in the maximum opening state and the translation center sleeve in the fully closed state.

[0040] Reference signs:

[0041] 1-outer casing 1; 11-inlet air duct; 2-sealing cover;

[0042] 3 - central body; 31 - central cone; 32 - straight wall cylinder;

[0043] 4 - translation center sleeve; 41 - connecting straight section; 42 - contraction section;

[0044] 5 - intermediate casing;

[0045] 6 - variable geometry lobe; 61 - planar section; 62 - cambered section;

[0046] 7 - lobe support plate;

[0047] 8 - angle adjustment device; 81 - synchronization ring; 82 - sliding rod; 83 - connecting rod; 84 - hinge mechanism; 85 - sealing cover;

[0048] 9 - hydraulic actuator; 10 - cavity; 12 - central cone support plate

[0049] 101 - inlet passage throat; 102 - variable geometry passage; 103 - inner bypass passage; 104 - outer bypass passage. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0051] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the usual meaning understood by those of ordinary skill in the art to which the present application belongs. The terms "first", "second" and similar words used in the present application do not represent any order, number or importance, but are only used to distinguish different components. Similarly, the terms "one", "an" or "the" and similar words do not represent a quantity limitation, but represent the existence of at least one. The terms "include" or "contain" and similar words mean that the elements or objects before the words cover the elements or objects listed after the words and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0052] It should be noted that "up", "down", "left", "right", "front" and "back" and the like used in the present application are only used to represent relative positional relationships, and when the absolute position of the described object changes, the relative positional relationships may also change accordingly.

[0053] Figure 1 is a structural schematic diagram of a duct switching device suitable for serial TBCC modal conversion provided by an embodiment of the present application; Figure 2 is a partial structural schematic diagram of a duct switching device suitable for serial TBCC modal conversion provided by an embodiment of the present application.

[0054] Referring to Figure 1 and Figure 2 , the duct switching device suitable for serial TBCC modal conversion provided by an embodiment of the present application comprises: an outer casing 1, a sealing cover 2, a central body 3, a translation central sleeve 4, an intermediate casing 5 and a variable-geometry lobe 6; the outer casing 1 is in a cylindrical shape and has an air inlet 11; the sealing cover 2 is in communication with an air outlet of the air inlet 11; the central body 3 is arranged in the air inlet 11; the central body 3 comprises: a central cone 31 and a straight-wall cylinder 32, and the central cone 31 is connected with the straight-wall cylinder 32; an annular passage formed between the straight-wall cylinder 32 and the outer casing 1 is an air inlet throat 101; the translation central sleeve 4 is arranged in the sealing cover 2; the translation central sleeve 4 is supported to move along an axial direction of the sealing cover 2; the translation central sleeve 4 comprises: a connecting straight section 41 and a contraction section 42, and the connecting straight section 41 is connected with the contraction section 42; the connecting straight section 41 is slidingly sleeved on the straight-wall cylinder 32; the intermediate casing 5 is in a cylindrical shape; the intermediate casing 5 separates an annular passage between the sealing cover 2 and the translation central sleeve 4 into an inner duct 103 and an outer duct 104; a plurality of variable-geometry lobes 6 are arranged around the air outlet of the air inlet 11; a first end of the variable-geometry lobe 6 is rotationally connected with the air outlet of the air inlet 11 in an axial direction of the outer casing 1; when two ends of the connecting straight section 41 are connected with the intermediate casing 5 and the straight-wall cylinder 32 respectively, and the variable-geometry lobe 6 is rotated to a side away from the intermediate casing 5, an annular passage between the variable-geometry lobe 6 and the connecting straight section 41, the air inlet throat 101 and the outer duct 104 form a ramjet passage, and the duct switching device is in a ramjet mode; when a maximum-diameter port of the contraction section 42 is connected with the straight-wall cylinder 32, and the variable-geometry lobe 6 is rotated to be connected with the intermediate casing 5, an annular passage between the variable-geometry lobe 6 and the contraction section 42, the air inlet throat 101 and the inner duct 103 form a turbine passage, and the duct switching device is in a turbine mode.

[0055] An annular passage formed between the variable-geometry lobe 6 and the connecting straight section 41 or the contraction section 42 of the translation central sleeve 4 is a variable-geometry passage 102; the air inlet throat 101, the variable-geometry passage 102 and the inner duct 103 are in communication to form a turbine passage; the air inlet throat 101, the variable-geometry passage 102 and the outer duct 104 are in communication to form a ramjet passage; when the translation central sleeve 4 moves to a state that two ends of the connecting straight section 41 are connected with the intermediate casing 5 and the straight-wall cylinder 32 respectively, the turbine passage is closed, and the duct switching device is in the ramjet mode; when a second end of the variable-geometry lobe 6 is rotated to be connected with the intermediate casing 5, the ramjet passage is closed, and the duct switching device is in the turbine mode.

[0056] In the present embodiment, the translation center sleeve 4 is movable along the axis direction of the outer casing 1, the connecting straight section 41 is cylindrical, and is sleeved on the outer wall of the straight wall cylinder 32 of the center body 3 to realize relative sliding under the action of external driving force; the contraction section 42 is designed in the shape of a truncated cone, one end connected with the connecting straight section 41 has a larger diameter, and the other end gradually contracts, and the conical surface is curved, which makes the turbine passage form a low-flow-loss "S" curved passage. Through the curved surface design of the contraction section 42 and the "S" curved passage structure, the flow loss of the airflow in the mode switching process is effectively reduced, and the propulsion efficiency is improved.

[0057] The annular variable-geometry passage 102 surrounded by the connecting straight section 41 or the contraction section 42 and the variable-geometry lobe 6 dynamically changes with the movement of the sleeve: when the translation center sleeve 4 moves forward along the axis direction of the outer casing 1, the volume of the variable-geometry passage 102 increases, the airflow entering the turbine passage increases, and vice versa, the volume of the variable-geometry passage 102 decreases, the airflow decreases, thereby realizing continuous flow regulation of the turbine passage; when the translation center sleeve 4 moves backward along the axis direction of the outer casing 1 to the limit position, the connecting straight section 41 is completely connected with the straight wall cylinder 32 and the intermediate casing 5, respectively, and the turbine passage is completely closed, at this time, the sleeve reaches the maximum backward stroke, and the system switches to the ram mode.

[0058] The variable-geometry lobe 6 can rotate around the airflow direction through a hinge structure, the first end is hinged with the outer casing 1, and the second end can be deflected up and down under the driving of external force, the number of lobes can be designed according to actual needs, and the shape can be a plate or sheet structure, and the present application does not limit the specific shape. In some embodiments, the variable-geometry lobe 6 is composed of a flat section 61 and an arc section 62, and the radius of the arc section 62 is ≥200mm. The variable-geometry lobe adopts the combined configuration of the flat section 61 and the arc section 62, wherein the flat section 61 is used to guide the smooth transition of the airflow, and the arc section 62 is matched with the "S" shaped low-loss flow passage of the turbine passage; by increasing the radius (R≥200mm) of the arc section 62, the local airflow velocity gradient of the leading edge of the intermediate casing 5 in the pure turbine mode can be effectively reduced, and the flow velocity distribution is more uniform; when the variable-geometry lobe 6 rotates to the closed position, the end of the arc section 62 is tightly matched with the annular surface of the intermediate casing 5 to realize zero-gap sealing and completely block the leakage of the ram passage airflow, and the contour of the arc section 62 can also avoid the flow separation phenomenon caused by the traditional right-angle sealing structure.

[0059] In other embodiments, the rotation angle range of the variable-geometry lobe 6 is 0°~ 44°.

[0060] When the variable geometry wave lobe 6 is deflected upward, the variable geometry channel 102 volume increases, the air flow into the ram channel increases, and vice versa, the channel volume decreases, the air flow decreases, thereby realizing the flow regulation of the ram channel. When the variable geometry wave lobe 6 is deflected downward to completely engage with the intermediate casing 5, the ram channel is completely closed, and the variable geometry wave lobe 6 reaches the maximum downward deflection angle.

[0061] The variable geometry wave lobe 6 can adjust the two-channel split ratio according to the combined power engine mode conversion requirements, on the basis of improving the aerodynamic performance of each channel state, maximally limiting the fluid transverse migration in the mode conversion process, reducing the spanwise flow loss, and improving the channel flow distribution efficiency. While obtaining rapid flow regulation, maintaining a high total pressure recovery coefficient, thereby ensuring the power output of the ram channel high-speed internal flow.

[0062] It should be noted that the center body 3 can be fixedly installed inside the outer casing 1 by at least three circumferentially uniformly distributed center cone support plates 12.

[0063] Figure 3 is a structural schematic view of the variable geometry wave lobe of the present application in a zero opening state and a full opening state of the translation center sleeve; Figure 4 is a structural schematic view of the variable geometry wave lobe of the present application in a maximum opening state and a full opening state of the translation center sleeve; Figure 5 is a structural schematic view of the variable geometry wave lobe of the present application in a maximum opening state and a full closing state of the translation center sleeve. The mode switching process is realized through the coordinated action of the translation center sleeve 4 and the variable geometry wave lobe 6, refer to Figures 3-5 , the specific coordination process is as follows: when the translation center sleeve 4 is moved forward to the maximum diameter end of the contraction section 42 and is in abutment with the straight wall cylinder 32, and the variable geometry wave lobe 6 is deflected downward to completely engage with the intermediate casing 5, the ram channel is completely closed, and the airflow enters the inner channel 103 through the connecting straight section 41 and the contraction section 42. The system is switched to the turbine mode; on the contrary, when the translation center sleeve 4 is moved backward to the connecting straight section 41 and is in abutment with the intermediate casing 5, and the variable geometry wave lobe 6 is deflected upward to the maximum angle, the turbine channel is completely blocked, and the airflow enters the outer channel 104 through the connecting straight section 41, and the system is switched to the ram mode.

[0064] The duct switching device suitable for the series TBCC mode conversion of the embodiment of the present application separates the airflow channel into the ram outer duct 104 and the turbine inner duct 103 through the intermediate casing 5, and utilizes the forward and backward movement of the translation center sleeve 4 and the up and down deflection of the variable geometry sector 6 to realize the continuous adjustment of the duct ratio, so as to complete the smooth transition of the engine thrust between the turbine mode and the ram mode, and avoid the thrust fluctuation caused by the airflow mutation; when the translation center sleeve 4 moves backward to the limit position and is completely connected with the intermediate casing 5, the turbine channel can be completely closed, and when the variable geometry sector 6 is deflected downward to be completely connected with the intermediate casing 5, the ram channel is completely closed; the device uses the variable geometry sector 6 and the translation center sleeve 4 to synchronously adjust the channel flow distribution ratio in the mode conversion process, realizes the mode conversion function, and can realize the continuous adjustment of the airflow in the through-flow state of the pure turbine channel, the pure ram channel and the intermediate transition state of the mode switching, optimizes the flow field, avoids the serious flow field distortion and the flow separation phenomenon, reduces the aerodynamic loss, and solves the thrust mutation problem existing in the traditional TBCC mode switching.

[0065] In some embodiments, referring to Figure 1 and Figure 2 the duct switching device further comprises: an angle adjusting device 8; the variable geometry sector 6 adjusts the rotation angle through the angle adjusting device 8; the angle adjusting device 8 comprises: an actuating device, a synchronous ring 81 and a transmission mechanism; the actuating device and the synchronous ring 81 are both arranged outside the outer casing 1; the actuating device drives the synchronous ring 81 to move along the axial direction of the outer casing 1; the synchronous ring 81 transmits the driving force to the variable geometry sector 6 through the transmission mechanism, and the variable geometry sector 6 rotates around the axial direction of the outer casing under the action of the driving force.

[0066] The actuating device can adopt a linear motor direct drive or a hydraulic actuating system to drive the synchronous ring 81 to do linear reciprocating motion, and each variable geometry sector 6 is connected with the synchronous ring 81 through an independent transmission mechanism, wherein the transmission mechanism adopts a connecting rod 83 structure or a gear mechanism to convert the linear motion of the synchronous ring 81 into the up and down deflection motion of the variable geometry sector 6; when the linear motor or the hydraulic cylinder pushes the synchronous ring 81 to move axially, the synchronous ring 81 drives each sector to rotate synchronously around the hinged shaft through the hinged swing of the connecting rod 83 or the meshing transmission of the gear and rack, so as to realize the angle coordinated control of the sector group.

[0067] The synchronous ring 81 is in the form of a circular ring and is sleeved outside the outer wall of the outer casing 1, and the synchronous ring 81 can move along the axial direction of the outer casing 1 outside the outer casing 1. The synchronous ring 81 can make all the variable geometry sectors 6 deflect synchronously according to the predetermined trajectory, and reliably adjust the flow volume of the annular channel between the variable geometry sector 6 and the translation center sleeve 4.

[0068] Specifically, in some embodiments, the transmission mechanism can include a sliding rod 82, a connecting rod 83, and a hinge mechanism 84; the first end of the connecting rod 83 is connected to the second end of the variable-geometry petal 6 through the hinge mechanism 84; the first end of the sliding rod 82 is fixedly connected to the synchronous ring 81, and the second end of the sliding rod 82 is connected to the second end of the connecting rod 83 through the hinge mechanism 84 and the movable hole on the seal cover 2.

[0069] The transmission mechanism adopts a sliding rod 82-connecting rod 83 linkage design. When the actuator drives the synchronous ring 81 to move linearly, the sliding rod 82 is driven to move axially, the connecting rod 83 is driven to swing in a plane through the hinge mechanism 84, and the variable-geometry petal 6 is further driven to rotate around the fixed hinge at the first end thereof. This design converts the linear motion of the synchronous ring 81 into the precise angular deflection of the variable-geometry petal 6 through the double hinge mechanism 84, and the movable hole provides a guide function for the sliding rod 82, which can still reliably transmit the actuating force in a high-pressure airflow environment.

[0070] In some embodiments, a sealing cover 85 is sleeved on the sliding rod 82, and the sealing cover 85 is used to seal the movable hole. The transmission mechanism is provided with a sealing structure at the cooperation position of the sliding rod 82 and the seal cover 2, and the sealing cover 85 is sleeved on the sliding rod 82 and forms a dynamic sealing cooperation with the movable hole on the seal cover 2. When the synchronous ring 81 drives the sliding rod 82 to move linearly, the sealing cover 85 sleeved on the sliding rod 82 always covers the movable hole, allowing the sliding rod 82 to move axially freely and effectively preventing high-pressure airflow from leaking through the movable hole. The sealing cover 85 can be made of flexible graphite or a metal bellows, which is a high-temperature-resistant sealing material, and can enable the transmission mechanism to operate reliably in a high-temperature and high-pressure environment of an engine.

[0071] In some embodiments, referring to Figure 1 and Figure 2 The duct switching device further includes a plurality of petal support plates 7; the petal support plates 7 are arranged around the air outlet of the intake duct 11, and the two ends of each petal support plate 7 are fixedly connected to the outer casing 1 and the intermediate casing 5, respectively; one variable-geometry petal 6 is arranged between any two adjacent petal support plates 7, and the two sides of the variable-geometry petal 6 are connected to the adjacent petal support plates 7, respectively.

[0072] The lobe support plate 7 of the invention adopts a variable configuration design gradually increasing in width along the radial direction of the cross-section center of the outer casing 1, and the front profile is formed by the space trajectory lines formed by the two side edges when the variable geometry lobe 6 rotates around the hinge, ensuring that the lobe always matches the support plate in the rotation range of 0°-44°, and completely eliminating the lateral overflow; the rear profile of the lobe support plate 7 is optimized according to the gradual change rule of the passage cross-sectional area, effectively inhibiting the lateral migration and flow separation of the main flow. In specific implementation, the variable geometry lobe 6 and the lobe support plate 7 adopt a circumferential staggered arrangement, and the lobe support plate 7 is rigidly fixed between the outer casing 1 and the intermediate casing 5 to form a support framework, and the variable geometry lobe 6 rotates and slides between adjacent support plates. This structure design can not only match the front profile of the lobe movement trajectory to realize dynamic sealing, but also can constrain the sliding fit structure in the circumferential direction to force the main flow to move in the flow direction, finally realizing the precise aerodynamic control of the variable geometry lobe 6 in the whole working condition rotation process without lateral leakage and horizontal flow, and reducing the flow loss in the duct switching process.

[0073] In some embodiments, referring to Figure 1 and Figure 2 The duct switching device further comprises: a hydraulic actuator 9; the inner wall of the conical surface of the center cone 31, the inner wall of the straight wall sleeve, and the inner wall of the translation center sleeve 4 form a cavity 10; the hydraulic actuator 9 is arranged in the cavity 10; the fixed end of the hydraulic actuator 9 is fixed to the inner wall of the conical surface of the center cone 31, and the driving end of the hydraulic actuator 9 is connected to the inner wall of the translation center sleeve 4; the translation center sleeve 4 is driven by the hydraulic actuator 9.

[0074] The hydraulic actuator 9 is installed in the cavity 10 formed by the inner wall of the center cone 31, the inner wall of the straight wall sleeve, and the inner wall of the translation center sleeve 4, fully utilizing the original structure space of the engine center body 3, and avoiding the flow passage blockage caused by the external additional actuator. The driving end of the hydraulic actuator 9 is a piston rod structure, and the end thereof can be designed in a hollow shape. The high-pressure hydraulic oil pushes the actuator piston rod to extend and retract, directly driving the translation center sleeve 4 to move forward and backward along the flow direction. When the translation center sleeve 4 moves, the inner wall thereof slides along the outer surface of the straight wall sleeve, and the hydraulic actuator 9 is always in the closed cavity 10, avoiding the hydraulic oil leakage to pollute the airflow. When switching the turbine mode, the variable geometry lobe 6 closes the ram passage, the hydraulic actuator 9 retracts, pulls the translation center sleeve 4 to move forward, and makes the contraction section 42 butt against the straight wall cylinder 32; when switching the ram mode, the variable geometry lobe 6 opens the ram passage, the hydraulic actuator 9 extends, pushes the sleeve to move backward, and makes the connection straight section 41 butt against the intermediate casing 5, and the turbine passage is closed.

[0075] The hydraulic actuating cylinder 9 is arranged in the closed cavity 10 formed by the inner wall of the central cone 31, the inner wall of the straight wall sleeve and the inner wall of the translation center sleeve 4, fully utilizing the internal space of the engine center body 3, avoiding the interference of the external actuating mechanism to the airflow channel, and realizing the compact layout; the driving end of the actuating cylinder is provided with a hollow designed piston rod structure, which is directly driven to move the translation center sleeve 4 in the axial direction under the driving of high-pressure hydraulic oil, and the inner wall of the translation center sleeve 4 is in sliding fit with the outer surface of the straight wall sleeve, so that the hydraulic actuating cylinder 9 is always in the closed cavity 10 during the actuating process, effectively preventing the oil leakage from polluting the airflow. The specific working process is as follows: when switching to the turbine mode, the variable geometry wave lobes 6 first close the ram channel, and at the same time, the hydraulic actuating cylinder 9 is retracted to pull the translation center sleeve 4 to move forward, so that the contraction section 42 is in butt joint with the straight wall cylinder 32; when switching to the ram mode, the variable geometry wave lobes 6 open the ram channel, the hydraulic actuating cylinder 9 is extended to push the sleeve to move backward, until the connecting straight section 41 is completely connected with the intermediate nacelle 5, and the reliable closing of the turbine channel is realized; the integrated hydraulic actuating system optimizes the space utilization and sealing design, ensures the large thrust actuating capacity, and solves the problems of flow channel blockage and medium pollution existing in the traditional external actuating mechanism.

[0076] The application also provides an internal flow regulation method of the axial symmetric wave lobe duct switching device for serial TBCC mode conversion.

[0077] S1: turbine mode to ram mode conversion: rotate the variable geometry wave lobes 6 to the side away from the intermediate nacelle 5, open the ram channel, connect the two ends of the connecting straight section 41 to the intermediate nacelle 5 and the straight wall cylinder 32 respectively, and close the turbine channel, so that the duct switching device is in the ram mode;

[0078] S2: ram mode to turbine mode conversion: connect the contraction section 42 with the largest diameter port to the straight wall cylinder 32, open the turbine channel, rotate the variable geometry wave lobes 6 to connect with the intermediate nacelle 5, and close the ram channel, so that the duct switching device is in the turbine mode.

[0079] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A duct switching device suitable for series TBCC mode switching, characterized in that, include: The outer casing is cylindrical and has an air intake duct. A sealing cover is connected to the air outlet of the air inlet; A central body is disposed within the air intake duct; the central body includes a central cone and a straight-walled cylinder, the central cone being connected to the straight-walled cylinder; the annular channel formed between the straight-walled cylinder and the outer casing is the air intake throat; A translation center sleeve is disposed inside the sealing cover; the translation center sleeve supports movement along the axial direction of the sealing cover; the translation center sleeve includes: a connecting straight section and a contraction section, the connecting straight section being connected to the contraction section; the connecting straight section is slidably sleeved on the straight wall cylinder; The intermediate casing is cylindrical; the intermediate casing divides the annular channel between the sealing cover and the translational center sleeve into an inner channel and an outer channel; Multiple variable geometry lobes are arranged around the air outlet of the air intake duct; the first end of each variable geometry lobe is rotatably connected to the air outlet of the air intake duct about the axis of the outer casing. When the two ends of the connecting straight section are respectively connected to the intermediate casing and the straight wall cylinder, and the variable geometry lobe rotates to the side away from the intermediate casing, the annular channel between the variable geometry lobe and the connecting straight section, the intake throat and the outer bypass form a stamping channel, and the bypass switching device is in stamping mode. When the maximum diameter port of the contraction section is connected to the straight-walled cylinder, and the variable geometry lobe rotates to connect with the intermediate casing, the annular channel between the variable geometry lobe and the contraction section, the intake throat and the inner duct form a turbine channel, and the duct switching device is in turbine mode.

2. The duct switching device for mode switching of series TBCC as described in claim 1, characterized in that, Also includes: Angle adjustment device; The variable geometry lobe adjusts the rotation angle via the angle adjustment device. The angle adjustment device includes: an actuating device, a synchronizing ring, and a transmission mechanism; Both the actuating device and the synchronizing ring are located outside the outer casing; the actuating device drives the synchronizing ring to move along the axial direction of the outer casing; The synchronization ring transmits the driving force to the variable geometry lobe through a transmission mechanism, and the variable geometry lobe rotates around the axis of the outer casing under the action of the driving force.

3. The duct switching device for mode switching of series TBCC according to claim 2, characterized in that, The transmission mechanism includes: a sliding rod, a connecting rod, and a hinge mechanism; The first end of the connecting rod is connected to the second end of the variable geometry lobe via a hinge mechanism; the first end of the sliding rod is fixedly connected to the synchronization ring, and the second end of the sliding rod passes through the movable hole on the sealing cover and is connected to the second end of the connecting rod via a hinge mechanism.

4. The duct switching device suitable for mode switching of series TBCC according to claim 3, characterized in that, A sealing cap is fitted onto the sliding rod, and the sealing cap is used to seal the movable hole.

5. The duct switching device suitable for mode switching of series TBCC according to claim 2, characterized in that, The rotation angle range of the variable geometry lobe is 0° to 44°.

6. The duct switching device for mode switching of series TBCC according to claim 1, characterized in that, Also includes: Multiple lobe support plates; the lobe support plates are arranged around the air outlet of the air intake duct, and the two ends of the lobe support plates are fixedly connected to the outer casing and the intermediate casing, respectively; a variable geometry lobe is arranged between any two adjacent lobe support plates, and the two sides of the variable geometry lobe are respectively attached to the adjacent lobe support plates.

7. The duct switching device for series TBCC mode switching according to claim 6, characterized in that, The width of the beam support plate gradually increases in the radial direction extending from the center of the cross-section of the outer casing.

8. The duct switching device for mode switching of series TBCC according to claim 1, characterized in that, The variable geometry lobe includes a planar segment and an arc segment; the arc segment is connected to the planar segment, and the planar segment is rotatably connected to the outer casing; the radius of the arc segment is greater than or equal to 200 mm.

9. The duct switching device for mode switching of series TBCC according to claim 1, characterized in that, Also includes: Hydraulic actuator; The inner wall of the conical surface of the central cone, the inner wall of the straight-walled sleeve, and the inner wall of the translational central sleeve form a cavity. The hydraulic actuator is disposed within the cavity; the fixed end of the hydraulic actuator is fixed to the inner wall of the conical surface of the central cone, and the driving end of the hydraulic actuator is connected to the inner wall of the translational central sleeve; the translational central sleeve is driven by the hydraulic actuator.

10. A control method for a duct switching device suitable for series TBCC mode switching, utilizing the duct switching device suitable for series TBCC mode switching as described in any one of claims 1 to 9, the control method comprising: Transition from turbine mode to stamping mode: The variable geometry lobe is rotated to the side away from the intermediate casing, the stamping channel is opened, and when the two ends of the connecting straight section are connected to the intermediate casing and the straight wall cylinder respectively, the turbine channel is closed, and the duct switching device is in stamping mode; Transition from stamping mode to turbine mode: Connect the maximum diameter port of the contraction section to the straight-walled cylinder, open the turbine channel, rotate the variable geometry lobe to connect with the intermediate casing, close the stamping channel, and the duct switching device is in turbine mode.

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