Throat stepless adjustable spray pipe with fixed inlet and outlet area

Abstract

The invention belongs to the technical field of ramjet engines, and particularly relates to a throat stepless adjustable spray pipe with fixed inlet and outlet areas, the spray pipe adopts a contraction and expansion structure and comprises a round-to-square section, a contraction section and an expansion section, and the inner molded surface of the spray pipe can be actively adjusted according to the flow change of an upstream engine to adapt to different incoming flow conditions. The motor rod is driven by the motor, the single-degree-of-freedom linear motion of the motor rod is converted into synchronous rotation motion of the contraction section and the expansion section, and meanwhile the throat area change meets the expected design target. Stepless adjustment of the throat is achieved under the condition that the inlet and outlet area and the length of the spray pipe are not changed, and the performance of the spray pipe under different incoming flow conditions can be guaranteed while the requirement for matching of different flows of an upstream engine can be met. In addition, according to the design of the wall surface type surface at the lap joint, the attachment degree of the contraction section and the expansion section of the spray pipe under the driving of a single power source is good through the design of the wall surface type surface at the lap joint according to the steps.

Description

Technical Field

[0001] This invention belongs to the field of ramjet engine technology, and in particular to a throat-infinitely adjustable nozzle with a fixed inlet and outlet area. Background Technology

[0002] Air-breathing engines are crucial to the propulsion systems of wide-range aircraft, and the exhaust nozzle, as a key thrust component, is directly related to engine performance. The contraction-expansion nozzle accelerates the expansion of the high-temperature, high-pressure combustion gases within the combustion chamber, converting internal energy into kinetic energy to generate thrust. The nozzle throat area significantly impacts the upstream engine combustion chamber. For a given mass flow rate, a smaller throat results in higher combustion chamber pressure, while a larger throat leads to lower pressure. Therefore, adjusting the nozzle throat area can meet flow requirements under different operating conditions, regulating engine thrust within a certain range. Furthermore, changes in the throat area also affect the nozzle's expansion ratio, influencing the degree of nozzle expansion to some extent.

[0003] Currently, although the nozzle technology matched with the air-breathing engine can meet the performance requirements of wide-range aircraft to a certain extent, there are still some shortcomings: (1) It is difficult to achieve stepless adjustment of the throat area under the condition that the adjustment method is rotating the wall and the inlet and outlet areas and the nozzle length are unchanged, so as to meet the flow requirements of the upstream combustion chamber; (2) The technology of synchronously rotating the wall of the nozzle contraction section and expansion section through a single degree of freedom needs to be strengthened. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a continuously adjustable throat nozzle with a fixed inlet and outlet area. By simultaneously controlling the walls of the contraction and expansion sections using a single power source, the throat area can be continuously adjusted while maintaining a constant inlet and outlet area and nozzle length. This allows for adjustments to the airflow rate to match engine operating conditions.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The present invention provides a throat-mounted steplessly adjustable nozzle with a fixed inlet and outlet area, comprising a pair of side plates and a pair of adjustment mechanisms symmetrically arranged between the pair of side plates. The area between the pair of adjustment mechanisms forms a nozzle under the cover of the pair of side plates. One end of the nozzle is the nozzle inlet and the other end is the nozzle outlet.

[0007] The adjustment mechanism includes a support plate fixed between a pair of side plates. A linear power source is provided on the support plate. A connecting member is provided on the linear actuator of the linear power source. The connecting member moves in a telescopic motion toward the adjustment mechanism on the opposite side.

[0008] The nozzle inlet is provided with a round-to-square section, which is fixed between a pair of side plates. The round-to-square section is hinged to a converging section away from the nozzle inlet. The nozzle outlet is provided with an expanding section, one end of which is hinged and rotated between a pair of side plates, and the other end of which overlaps the end of the converging section away from the end hinged to the round-to-square section.

[0009] A hinge seat is provided on the contraction section near the round-to-square section. A contraction section adjustment rod is provided between the hinge seat and the connecting piece. One end of the contraction section adjustment rod is hinged to the connecting piece, and the other end is hinged to the hinge seat.

[0010] A hinge seat is also provided in the middle of the expansion section. An expansion section adjustment rod is provided between the hinge seat and the connecting member. One end of the expansion section adjustment rod is hinged to the connecting member, and the other end is hinged to the hinge seat.

[0011] The connection point between the contraction section and the expansion section is the adjustable part of the nozzle throat. The adjustable parts of the nozzle throat of one adjustment mechanism and the adjustable parts of the nozzle throat of another adjustment mechanism move synchronously. The opening of the nozzle throat is dynamically adjusted through their respective connecting parts to control the flow rate of the nozzle.

[0012] As a further preferred option, the surface profile of the contraction section adopts the Vickers curve design, and the surface profile of the expansion section adopts the characteristic line method design, thereby ensuring the performance of the nozzle.

[0013] As a further preferred option, the surface design of the overlap between the contraction and expansion sections is carried out according to the following steps:

[0014] S1, the rotation point of the given contraction segment and the circular-to-square segment is the first rotation point A. , Given the connection point B between the contraction segment and the expansion segment. , Given the rotation point of the expansion segment and the side plate as the second rotation point C ( , Given the rotational angular velocity of the contraction segment. Given the rotational angular velocity of the expansion segment ;

[0015] S2, Connection point B ( , ) at rotational angular velocity Around the first rotation point A ( , Rotate clockwise Δ After a certain time, the rotated point D is obtained. , The coordinates of point D satisfy the following relationship:

[0016]

[0017] Rotated point D( , ) around the second rotation point C ( , ) with rotational angular velocity Rotate clockwise Δ After a certain time, the rotated point is obtained. ( , ), The coordinates of the points satisfy the following relationship:

[0018]

[0019] S3, Connection point B ( , ) at rotational angular velocity Around the first rotation point A ( , Rotate clockwise Δ After a certain time, the rotated point E is obtained. , The coordinates of point E satisfy the following relationship:

[0020]

[0021] Rotated point E( , ) around the second rotation point C ( , ) with rotational angular velocity Rotate clockwise Δ After a certain time, the rotated point is obtained. ( , ), The coordinates of the points satisfy the following relationship:

[0022]

[0023] S4, using connection point B ( , ), the point after rotation ( , ) and the rotated point ( , By fitting the curve, the shape of the overlap is obtained. .

[0024] This invention proposes a method to achieve stepless adjustment of the throat area by synchronously adjusting the contraction and expansion sections with a single degree of freedom, while ensuring that the inlet and outlet areas and nozzle length remain unchanged. This is to adapt to the matching requirements of different flow parameters of the upstream engine and ensure the performance of the nozzle under different incoming flow conditions. In addition, the design of the wall profile at the overlap section according to the above steps can make the nozzle contraction and expansion sections fit well under the drive of a single motor. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a throat-infinitely adjustable nozzle with a fixed inlet and outlet area, as described in an embodiment of the present invention.

[0026] Figure 2 This is a profile of a throat-infinitely adjustable nozzle with a fixed inlet and outlet area as described in an embodiment of the present invention, when the pressure ratio is 50.

[0027] Figure 3 This is a profile of a throat-infinitely adjustable nozzle with a fixed inlet and outlet area as described in an embodiment of the present invention, when the pressure ratio is 108.

[0028] Figure 4 This is a diagram showing the adjustment position changes at the overlap of the nozzle design in an embodiment of the present invention;

[0029] Figure 5 This is a physical image of the present invention. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] like Figure 1 As shown, a continuously adjustable nozzle with a fixed inlet and outlet area, a pair of side plates, and a pair of adjustment mechanisms symmetrically arranged between the pair of side plates. The area between the pair of adjustment mechanisms forms a nozzle under the cover of the pair of side plates. One end of the nozzle is a nozzle inlet 19, and the other end is a nozzle outlet 20.

[0032] The adjustment mechanism on one side includes: the upper half of the round-to-square section 1, the upper wall of the contraction section 3, the upper wall of the expansion section 5, the adjustment link of the upper contraction section 7, the adjustment link of the upper expansion section 9, the upper connecting piece 11, the upper support plate 13, the upper linear power source 15, and the upper linear actuator 17.

[0033] The nozzle inlet 19 is provided with a round-to-square upper half 1, which is fixed between a pair of side plates. The round-to-square upper half 1 is hinged to a contraction section upper wall 3 away from the nozzle inlet. The nozzle outlet 20 is provided with an expansion section upper wall 5, one end of which is hinged and rotated between a pair of side plates, and the other end of which overlaps the contraction section upper wall 3 at the end of the round-to-square upper half 1 away from the hinge.

[0034] A hinge seat is provided on the upper wall surface 3 of the contraction section near the upper half 1 of the round-to-square section. An upper contraction section adjustment rod 7 is provided between the hinge seat and the upper half connector 11. One end of the upper contraction section adjustment rod 7 is hinged to the upper half connector 11, and the other end is hinged to the hinge seat.

[0035] A hinge seat is also provided in the middle of the upper wall 5 of the expansion section. An upper expansion section adjustment rod 9 is provided between the hinge seat and the upper half connecting member 11. One end of the upper expansion section adjustment rod 9 is hinged to the upper half connecting member 11, and the other end is hinged to the hinge seat.

[0036] The connection point between the upper wall surface 3 of the contraction section and the upper wall surface 5 of the expansion section is the adjustable point of the nozzle throat of the adjustment mechanism on this side. The throat area is adjusted by driving the upper wall surface 3 of the contraction section and the upper wall surface 5 of the expansion section to rotate synchronously.

[0037] The other side adjustment mechanism includes: the lower half of the round-to-square section 2, the lower wall of the contraction section 4, the lower wall of the expansion section 6, the lower half contraction section adjustment link 8, the lower half expansion section adjustment link 10, the lower half connector 12, the lower half support plate 14, the lower half linear power source 16, and the lower half linear actuator 18.

[0038] The nozzle inlet 19 is provided with a lower half of a circular-to-square section 2, which is fixed between a pair of side plates. The lower half of the circular-to-square section 2 is hinged to a lower wall surface 4 of a contraction section away from the nozzle inlet. The nozzle outlet 20 is provided with a lower wall surface 6 of an expansion section. One end of the lower wall surface 6 of the expansion section is hinged and rotated between a pair of side plates, and the other end of the lower wall surface 6 of the expansion section overlaps the lower wall surface 4 of the contraction section away from the end of the lower half of the circular-to-square section 2.

[0039] A hinge seat is provided on the lower wall surface 4 of the contraction section near the lower half 2 of the round-to-square section. A lower half contraction section adjustment rod 8 is provided between the hinge seat and the lower half connector 12. One end of the lower half contraction section adjustment rod 8 is hinged to the lower half connector 12, and the other end is hinged to the hinge seat.

[0040] A hinge seat is also provided in the middle of the lower wall 6 of the expansion section. A lower expansion section adjustment rod 10 is provided between the hinge seat and the lower half connector 12. One end of the lower expansion section adjustment rod 10 is hinged to the lower half connector 12, and the other end is hinged to the hinge seat.

[0041] The connection point between the lower wall surface 4 of the contraction section and the lower wall surface 6 of the expansion section is the adjustable point of the nozzle throat of the adjustment mechanism on this side. The throat area is adjusted by driving the lower wall surface 4 of the contraction section and the lower wall surface 6 of the expansion section to rotate synchronously.

[0042] The upper linear actuator 17 is connected to the upper linear power source 15, and the lower linear actuator 18 is connected to the lower linear power source 16, and moves linearly under the drive of the upper linear power source 15 and the lower linear power source 16.

[0043] The nozzle throat adjustable section of one regulating mechanism and the nozzle throat adjustable section of another regulating mechanism move synchronously, and dynamically adjust the opening of the nozzle throat through their respective connecting parts 11 to control the nozzle flow rate.

[0044] Specifically, the upper linear power source 15 drives the upper linear actuator 17 to perform linear reciprocating motion, which in turn drives the upper connector 11 to perform linear reciprocating motion. At the same time, the upper connector 11 is connected to the upper wall surface 3 of the contraction section and the upper wall surface 5 of the expansion section through the upper contraction section adjustment link 7 and the upper expansion section adjustment link 9, forming a parallelogram linkage mechanism, which converts the linear reciprocating motion of the upper connector 11 into the synchronous rotational motion of the upper wall surface 3 of the contraction section and the upper wall surface 5 of the expansion section. The lower half linear power source 16 drives the lower half linear actuator 18 to perform linear reciprocating motion, which in turn drives the lower half connector 12 to perform linear reciprocating motion. At the same time, the lower half connector 12 is connected to the lower wall surface 4 of the contraction section and the lower wall surface 6 of the expansion section through the lower half contraction section adjustment link 8 and the upper half expansion section adjustment link 10, forming a parallelogram linkage mechanism, which converts the linear reciprocating motion of the lower half connector 12 into the synchronous rotational motion of the lower wall surface 4 of the contraction section and the lower wall surface 6 of the expansion section.

[0045] like Figure 1As shown in the example, the upper wall surface 3 of the contraction section and its hinge point, as well as the upper wall surface 5 of the expansion section and its hinge point, both form an L-shaped structure. The angle formed between the upper half of the contraction section adjusting link 7 and the upper wall surface 3 is consistent with the angle formed between the upper half of the expansion section adjusting link 9 and the upper wall surface 5 of the expansion section. That is, when the upper half of the connecting piece 11 is pushed downward, the upper wall surface 5 of the expansion section is pushed by the upper half of the expansion section adjusting link 9 to achieve counterclockwise rotation of the upper wall surface 5 of the expansion section. Rod 7 pushes the upper wall of the contraction section 3 to achieve clockwise rotation of the upper wall of the contraction section 3. Conversely, when the upper connecting piece 11 is pulled back, the upper wall of the expansion section 5 is pulled back by the upper expansion section adjusting rod 9 to achieve clockwise rotation of the upper wall of the expansion section 5. The upper wall of the contraction section 3 is also pushed by the upper contraction section adjusting rod 7 to achieve counterclockwise rotation of the upper wall of the contraction section 3. The position adjustment is achieved at the overlap between the two, that is, the opening degree of the throat is adjusted. Correspondingly, the adjustment mechanism on the opposite side adopts the same principle, which will not be described in detail.

[0046] The above method achieves the goal of synchronous rotation of the contraction and expansion sections through single-degree-of-freedom motion, and the change in throat area meets the expected design objectives.

[0047] The areas of the nozzle inlet surface 19 and the nozzle outlet surface 20 remain unchanged, the nozzle length remains unchanged, and the throat is infinitely adjustable.

[0048] The inner surfaces of the upper wall 3 and lower wall 4 of the contraction section are designed using Vickers curves, while the inner surfaces of the upper wall 5 and lower wall 6 of the expansion section are designed using the characteristic line method, thereby ensuring the performance of the nozzle.

[0049] In conventional designs, the fit between the contraction and expansion sections is not considered, resulting in larger gaps and greater airflow leakage. To reduce airflow leakage, this invention incorporates the following design, which improves the fit at the overlap to a certain extent and reduces airflow leakage.

[0050] like Figure 4 As shown, the surface design at the overlap of the contraction and expansion sections is carried out according to the following steps (taking two points as an example):

[0051] S1, the rotation point of the given contraction segment and the circular-to-square segment is the first rotation point A. , Given the connection point B between the contraction segment and the expansion segment. , Given the rotation point of the expansion segment and the side plate as the second rotation point C ( , Given the rotational angular velocity of the contraction segment. Given the rotational angular velocity of the expansion segment ;

[0052] S2, Connection point B ( , ) at rotational angular velocity Around the first rotation point A ( , Rotate clockwise Δ After a certain time, the rotated point D is obtained. , The coordinates of point D satisfy the following relationship:

[0053]

[0054] Rotated point D( , ) around the second rotation point C ( , ) with rotational angular velocity Rotate clockwise Δ After a certain time, the rotated point is obtained. ( , ), The coordinates of the points satisfy the following relationship:

[0055]

[0056] S3, Connection point B ( , ) at rotational angular velocity Around the first rotation point A ( , Rotate clockwise Δ After a certain time, the rotated point E is obtained. , The coordinates of point E satisfy the following relationship:

[0057]

[0058] Rotated point E( , ) around the second rotation point C ( , ) with rotational angular velocity Rotate clockwise Δ After a certain time, the rotated point is obtained. ( , ), The coordinates of the points satisfy the following relationship:

[0059]

[0060] S4, using connection point B ( , ), the point after rotation ( , ) and the rotated point ( , By fitting the curve, the shape of the overlap is obtained. .

[0061] Taking a one-sided adjustment mechanism as an example, the resulting profile is obtained through design. Theoretically, the upper wall surface 3 of the nozzle's contraction section and the upper wall surface 5 of the expansion section can remain in contact during rotation. However, the actual rotational angular velocity driven by a single motor during rotation is... and It is not a fixed value, therefore the designed surface After optimization through motion simulation, the final upper wall surface 3 of the nozzle contraction section and the upper wall surface 5 of the expansion section are obtained, which achieves the purpose of improving the fit of the overlap and reducing the amount of air leakage to a certain extent.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A throat-area constant exit-area controllable nozzle, characterized by: The nozzle comprises a pair of side plates and a pair of adjusting mechanisms symmetrically arranged between the side plates, and a region between the adjusting mechanisms is covered by the side plates to form a nozzle, one end of which is a nozzle inlet and the other end is a nozzle outlet; The adjusting mechanism comprises a support plate fixed between the side plates, and a linear power source is arranged on the support plate, and a connecting piece is arranged on a linear actuator of the linear power source, and the connecting piece is arranged to extend and retract towards the adjusting mechanism on the opposite side; A round-to-square section is arranged at the nozzle inlet, the round-to-square section is fixed between the side plates, and a contraction section is hingedly arranged on the round-to-square section away from the nozzle inlet; an expansion section is arranged at the nozzle outlet, one end of the expansion section is hingedly arranged between the side plates, and the other end of the expansion section is overlapped on the end of the contraction section away from the round-to-square section; A hinge seat is arranged on the contraction section close to the round-to-square section, and a contraction section adjusting connecting rod is arranged between the hinge seat and the connecting piece, one end of the contraction section adjusting connecting rod is hingedly arranged on the connecting piece, and the other end of the contraction section adjusting connecting rod is hingedly arranged on the hinge seat; A hinge seat is also arranged on the expansion section at a middle position, and an expansion section adjusting connecting rod is arranged between the hinge seat and the connecting piece, one end of the expansion section adjusting connecting rod is hingedly arranged on the connecting piece, and the other end of the expansion section adjusting connecting rod is hingedly arranged on the hinge seat; The connecting point of the contraction section and the expansion section is a nozzle throat adjustable part, the nozzle throat adjustable part of one adjusting mechanism and the nozzle throat adjustable part of the other adjusting mechanism are relatively synchronously movable, and the opening degree of the nozzle throat is dynamically adjusted through the connecting pieces to control the flow of the nozzle.

2. The inlet and outlet area constant throat stepless adjustable nozzle according to claim 1, characterized in that: The inner profile of the contraction section adopts a Vickers curve design, and the inner profile of the expansion section adopts a characteristic line method design, thereby ensuring the performance of the nozzle.

3. A variable area throat inlet and outlet nozzle according to claim 2, wherein The profile design of the overlapping part of the contraction section and the expansion section is performed according to the following steps: S1, the rotation point of the given contraction segment and the circular-to-square segment is the first rotation point A. , Given the connection point B between the contraction segment and the expansion segment. , Given the rotation point of the expansion segment and the side plate as the second rotation point C ( , Given the rotational angular velocity of the contraction segment. Given the rotational angular velocity of the expansion segment ; S2, connection point B , ) rotates clockwise around the first rotation point A at an angular velocity of , ) for a time of Δ , a rotated point D , ) is obtained, and the coordinates of the point D satisfy the relationship: ； The rotated point D , ) rotates around the second rotation point C , ) with the rotation angular velocity clockwise by Δ time, and the rotated point ( , ), The coordinates of the point satisfy the relationship: ； S3, connecting point B , ) rotates clockwise around the first rotation point A at an angular velocity of , ) for a time of Δ , a rotated point E , ) is obtained, and the coordinates of the point E satisfy the relationship: ； The rotated point E , ) rotates around the second rotation point C , ) with the rotation angular velocity After rotating clockwise by Δ time, the rotated point ( , ), The coordinates of the point satisfy the relationship: ； S4, using connection point B ( , ), the point after rotation ( , ) and the rotated point ( , By fitting the curve, the shape of the overlap is obtained. .

4. The inlet area and outlet area fixed throat area variable exit nozzle according to claim 3, characterized in that: The profile obtained by the design In theory, the contraction section and the expansion section can keep close at any time during rotation, but the rotation angular velocity during the actual rotation driven by a single motor And Is not a constant value, so the profile obtained by the design After optimization by motion simulation, the final contraction section and the expansion section are obtained, which can improve the close degree of the lap joint to a certain extent and reduce the air leakage.

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