Flow field stabilizing mechanism of dual-throat aerodynamic vectoring nozzle and control method thereof

Abstract

The application discloses a flow field stabilizing mechanism of a double-throat aerodynamic vector nozzle and a control method thereof, which comprises two groups of guide vane arrays arranged in the double-throat aerodynamic vector nozzle and a servo control mechanism located outside the double-throat aerodynamic vector nozzle. When the double-throat aerodynamic vector nozzle is in a working state, according to the profile and flow field structure of the flow channel in the nozzle, the opening angle of the guide vane is adjusted through the servo control mechanism, so that the main flow of the double-throat aerodynamic vector nozzle is stabilized, and the vector performance of the double-throat aerodynamic vector nozzle is ensured, and the propelling efficiency and stability of the double-throat aerodynamic vector nozzle are improved.

Description

Technical Field

[0001] This invention relates to a flow field stabilization mechanism and control method for a dual-throat aerodynamic vector nozzle, belonging to the field of aircraft propulsion system design, particularly dual-throat aerodynamic vector nozzles. Background Technology

[0002] Currently, fluid thrust vectoring nozzles are gradually becoming a research focus and hot topic in various countries due to their simple structure and light weight, and are expected to enter engineering applications in the near future. With the development of vector propulsion technology, aerodynamic vectoring nozzles have received considerable attention in recent years due to their advantages such as good airflow vector deflection effect, stable angle, simplicity, light weight, and high reliability. Among them, the dual-throat aerodynamic vectoring nozzle, which forms a dual-throat system by setting a convergent-divergent-convergent nozzle, with the area of ​​the second throat slightly larger than that of the first throat, is most common. The disturbance applied at the first throat causes the velocity cross-section of the airflow at that throat to deflect, and then the disturbance is amplified in the divergent-convergent section in front of the second throat, generating a stable thrust vector. Its fixed geometric configuration, simple mechanical structure, and excellent vectoring performance have made it a research focus for various countries.

[0003] The rectangular two-dimensional dual-throat aerodynamic vectoring nozzle operates in two states: non-vectoring and vectoring. In the non-vectoring state, there is no disturbance at the first throat. The main stream enters the expansion section after passing through the first throat. Due to entrainment, a reflux zone forms in the cavity between the first and second throats, causing disturbance to the main stream. In the vectoring state, the main stream is disturbed on one side of the first throat through micro-jet propulsion. After entering the cavity, the main stream amplifies the disturbance effect on one side through adhesion to the wall before exiting from the second throat, forming a reflux zone on the other side, which also disturbs the main stream. The disturbance to the main stream caused by the reflux zone in both states results in jittering of the main stream during flow, severely affecting its propulsion efficiency and stability. Summary of the Invention

[0004] Purpose of the invention: In order to overcome the shortcomings of the prior art, the present invention provides a flow field stabilization mechanism to improve and solve the technical problem of unstable internal flow field in existing rectangular binary double-throat aerodynamic vector nozzles.

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

[0006] A flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle includes a first guide vane group (2) arranged above the interior of the dual-throat aerodynamic vector nozzle and a second guide vane group (3) arranged below the interior of the dual-throat aerodynamic vector nozzle. The first guide vane group (2) and the second guide vane group (3) are symmetrically distributed and are controlled by a servo mechanism respectively. The first guide vane group (2) and the second guide vane group (3) each contain a number of individual guide vanes. Each of the guide vanes has a rotating shaft on one side. The guide vanes rotate around the rotating shaft under the control of the same servo mechanism to open or close.

[0007] Preferably, the cross-section of the guide vane is a parallelogram, and the length of the base of the cross-section of the guide vane is l. x The length L of the cavity between the first and second throats of the dual-throat aerodynamic vector nozzle is 1 / 9 to 1 / 6; the height l of the cross-section of the guide vane is... y The throat height H of a dual-throat aerodynamic vector nozzle th1 1 / 25 to 1 / 35; without considering the clearance required for rotation, the length l of the guide vane z The distance between the two sidewalls of the dual-throat aerodynamic vector nozzle is equal.

[0008] Preferably, the cross-section of the guide vane further includes an airfoil, and the types of airfoils include plano-convex, symmetrical, concave-convex, S-shaped, biconvex, and special types.

[0009] Preferably, both the first guide vane group (2) and the second guide vane group (3) consist of 2 to 5 guide vanes; to ensure that the guide vanes act on the first 1 / 3 to 1 / 2 of the expansion section between the first and second throats of the dual-throat aerodynamic vector nozzle, the bottom edge length l of the guide vane cross-section is... x The number of guide vanes n in each guide vane group and the cavity length L satisfy the following relationship: n·l x = (0.33~0.50)×L.

[0010] Preferably, to ensure the rotational capability of the guide vanes, a rotating shaft is provided on one side of each guide vane. The plane formed by the axes of the multiple rotating shafts coincides with the plane formed by half the height of the guide vane's cross-section. The intersection line of the plane formed by half the height of the guide vane's cross-section and the short side of the guide vane's cross-section is obtained, and the distance between the axis of the rotating shaft and the intersection line is 1 / 6l. x ~1 / 3l x .

[0011] Preferably, for the first guide vane group (2), the multiple rotating shafts it contains are all coplanar and are all located on plane F1 defined by the line connecting the upper edge of the first throat and the upper edge of the second throat; for the second guide vane group (3), the multiple rotating shafts it contains are all coplanar and are all located on plane F2 defined by the lower edge of the first throat and the lower edge of the second throat.

[0012] Preferably, for the first guide vane group (2) and the second guide vane group (3), the distance x between the rotation axes of adjacent guide vanes is 1 / 9 to 1 / 6 of the cavity length L between the first and second throats of the double-throat aerodynamic vector nozzle, that is, the distance x between the rotation axes of adjacent guide vanes is equal to the width l of the guide vane. x equal.

[0013] Preferably, the servo control mechanism is located outside the dual-throat aerodynamic vector nozzle and controls the first guide vane group (2) and the second guide vane group (3) respectively. The servo mechanism also controls the same group of guide vanes to have the same opening angle δ.

[0014] A control method for the flow field stabilization mechanism of a dual-throat aerodynamic vector nozzle, wherein the first guide vane group (2) and the second guide vane group (3) have two working states: open and closed.

[0015] In the open state, the guide vanes of both the first guide vane group (2) and the second guide vane group (3) rotate around the axis of rotation through an angle δ toward the center of the double-throat aerodynamic vector nozzle. δ is defined as follows: max Maximum opening angle: δ max =β±3°; β is the contraction angle of the contraction section of the dual-throat nozzle;

[0016] When δ = 0°, the first guide vane group (2) and the second guide vane group (3) are in a closed state.

[0017] Beneficial effects:

[0018] This invention addresses the shortcomings of dual-throat aerodynamic vector nozzles by utilizing the characteristics of their internal surface and the flow field structure. Two sets of guide vane arrays are placed in the expansion section between the first and second throats. Through a louver-like layout, the internal flow field of the nozzle is stabilized in both non-vector and vector states while ensuring that the nozzle's vector performance remains essentially unchanged. This significantly reduces the impact of the recirculation zone on the mainstream, thereby improving the nozzle's propulsion efficiency and stability.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) Without changing the internal profile of the dual-throat aerodynamic vector nozzle, by controlling the closing and opening of the guide vanes and their opening angle, the disturbance of the concave cavity recirculation zone to the mainstream is isolated without affecting the vector performance of the nozzle, thereby enabling the nozzle to have more stable propulsion performance and improve propulsion efficiency.

[0021] (2) This invention can be applied to various existing dual-throat pneumatic vector nozzles and their improved configurations, and has a wide range of applications. Attached Figure Description

[0022] Figure 1 This is an isometric view of a typical configuration of the present invention, where 1 is a typical configuration of a dual-throat aerodynamic vector nozzle, 2 is a set of guide vane arrays, and 3 is another set of guide vane arrays, each set of guide vane arrays consisting of 3 guide vanes.

[0023] Figure 2 This is a front view of a typical configuration of the present invention, where l is the length of the cavity and H... th1 denoted as the thickness height of the upstream throat of the dual-throat aerodynamic vector nozzle, x is the distance between the rotation axes of adjacent guide vanes in the guide vane array, and δ is the opening angle of the guide vanes.

[0024] Figure 3 This is an isometric view of the guide vane of the present invention, where 1 is the guide vane and 2 is the rotation axis I of the guide vane.

[0025] Figure 4 This is a cross-sectional view of the guide vane of the present invention. The guide vane is plate-shaped, and its cross-section is a parallelogram, wherein l x l is the width of the guide vane. y For the thickness of the guide vane, l z This refers to the length of the guide vane.

[0026] Figure 5 In this improved version of the invention, 1 is a typical configuration of a dual-throat aerodynamic vector nozzle, 2 is a set of guide vane arrays, and 3 is another set of guide vane arrays, each set of guide vane arrays consisting of 2 guide vanes.

[0027] Figure 6 In this improved version of the invention, 1 is a typical configuration of a dual-throat aerodynamic vector nozzle, 2 is a set of guide vane arrays, and 3 is another set of guide vane arrays, each set of guide vane arrays consisting of 5 guide vanes.

[0028] Figure 7 In this improved version of the invention, 1 is a typical configuration of a dual-throat aerodynamic vector nozzle, 2 is a set of guide vane arrays, and 3 is another set of guide vane arrays. Each set of guide vane arrays consists of 3 guide vanes, and the cross-section of the guide vanes is streamlined. Detailed Implementation

[0029] The present invention will now be further described with reference to the accompanying drawings.

[0030] A flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle includes: two sets of guide vane arrays composed of several adjustable guide vanes and their servo control mechanism.

[0031] The two sets of guide vane arrays are located between the expansion sections of the first and second throats.

[0032] To determine the position of the guide vanes, the expansion angle of the expansion section after the first throat of the double-throat nozzle is defined as α, the contraction angle of the contraction section is defined as β, and the expansion angle of the line connecting the first and second throats of the double-throat nozzle is defined as the total expansion angle γ of the nozzle.

[0033] Furthermore, the two sets of guide vane arrays are symmetrically distributed about the plane of symmetry of the rectangular binary dual-throat aerodynamic vector nozzle.

[0034] Furthermore, each group of guide vane arrays contains 3 guide vanes, each guide vane can rotate around a certain axis I, and the axis is located on the guide vane.

[0035] Furthermore, in the same group of guide vane arrays, the rotation axes of the guide vanes are coplanar and all are located on the plane F1 (F2) determined by the upper (lower) side of one throat and the upper (lower) side of the two throats.

[0036] Furthermore, in the same group of guide vane arrays, the guide vanes are arranged linearly, and the rotation axes of each group of guide vanes are parallel and perpendicular to the side wall of the rectangular two-dimensional double-throat aerodynamic vector nozzle.

[0037] Furthermore, in the same group of guide vane arrays, the distance x between the rotating shafts of adjacent guide vanes is 1 / 9 to 1 / 6 of the length L of the expansion section between the first and second throats of the rectangular binary double-throat aerodynamic vector nozzle.

[0038] Furthermore, the aforementioned guide vanes are plate-shaped, and without considering the clearance required for rotation, their length l z It is equidistant from the sidewall of the rectangular binary dual-throat aerodynamic vector nozzle.

[0039] Furthermore, the cross-section of the aforementioned guide vane is a parallelogram, and the acute angle of the parallelogram is equal to α-γ; its width l x The length L of the expansion section between the first and second throats of the rectangular two-throat aerodynamic vector nozzle is 1 / 9 to 1 / 6; its height l y For a two-dimensional dual-throat aerodynamic vector nozzle, the throat height H th1 1 / 25 to 1 / 35 of.

[0040] Furthermore, the axis of the guide vane shaft passes through the 1 / 2 thickness plane of the guide vane and lies between the six-divided plane and the three-divided plane on the width of the guide vane. That is, the distance between the axis of the shaft and the intersection line of the 1 / 2 thickness plane and the side wall of the guide vane is 1 / 6l. x ~1 / 3l x .

[0041] Furthermore, the aforementioned distance x between the rotation axes of adjacent guide vanes and the width l of the guide vanes... x equal.

[0042] Furthermore, the guide vanes in each group of guide vane arrays are linked together, and during operation, the magnitude and direction of their rotation around their respective fixed axis I are the same.

[0043] Furthermore, the operating states of each group of guide vane arrays include both closed and open states. In the closed state, the same group of guide vanes are in a coplanar state; in the open state, the same group of guide vanes rotates around the rotation axis in a direction that decreases the angle between the guide vanes and the wall of the expansion section of the double-throat aerodynamic vector nozzle cavity by a certain angle, defined as the opening angle δ. max To achieve the maximum opening angle, δ is set based on the flow conditions of the cavity in both the non-vectoring and vectoring states of the nozzle. max When β ± 3° and δ = 0°, the guide vane array is in a closed state.

[0044] The servo control mechanism is located at a suitable position outside the dual-throat aerodynamic vector nozzle, and can control two sets of guide vane arrays respectively. The servo mechanism can control the same set of guide vanes in linkage, that is, the servo mechanism controls the same set of guide vanes to open at the same angle δ.

[0045] The flow field stabilization mechanism of the dual-throat aerodynamic vector nozzle employs the following control methods for different operating states of the nozzle:

[0046] When the nozzle is in a non-vectoring state, the servo control mechanism controls the two sets of guide vane arrays to keep them in a closed state, i.e., δ=0°, thereby isolating the concave cavity backflow area from the disturbance of the main flow.

[0047] When the nozzle is in a vectoring state, taking upward vectoring as an example, a disturbance is applied to the upper side of the throat. The servo control mechanism controls the upper guide vane array to be in a closed state, isolating the upper cavity from the disturbance of the main stream. It also controls the lower guide vane array to be in an open state, allowing the deflected main stream to pass through the guide vanes and enter the lower cavity. The opening angle δ increases with the increase of the disturbance intensity; that is, the larger the angle of the main stream deflection, the larger the guide vane opening angle δ, but it does not exceed the maximum opening angle δ. max The vector deflection is the opposite.

[0048] like Figure 1As shown, the dual-throat aerodynamic vector nozzle equipped with the aforementioned flow field stabilization mechanism consists of a typical dual-throat aerodynamic vector nozzle configuration, two sets of guide vane arrays each composed of three adjustable guide vanes, and a servo control mechanism. The two sets of guide vane arrays are located between the expansion sections of the first and second throats and are symmetrically distributed about the plane of symmetry of the rectangular binary dual-throat aerodynamic vector nozzle. Each guide vane can rotate about its axis I.

[0049] To ensure that each guide vane can rotate, the rotation axes of the guide vanes in the same array are parallel and coplanar, and arranged linearly. The rotation axes must be perpendicular to the sidewall of the rectangular two-dimensional dual-throat aerodynamic vector nozzle.

[0050] like Figure 2 As shown, in the same group of guide vane arrays, the distance x between the rotating shafts of adjacent guide vanes is 1 / 9 to 1 / 6 of the length L of the expansion section between the first and second throats of the rectangular binary double-throat aerodynamic vector nozzle. That is, the area where the guide vane array is arranged is the first 1 / 3 to 1 / 2 of the expansion section.

[0051] like Figure 3 , Figure 4 The guide vanes shown should be plate-shaped, and their length l should be [not specified] to ensure their stabilizing effect on the fluid throughout the flow channel. z The distance between the guide vane and the sidewall of the rectangular two-throat aerodynamic vector nozzle should be equal. To ensure its performance in different modes, the guide vane has a parallelogram cross-section, and the acute angle of the parallelogram is equal to the angle between the wall of the expansion section of the double-throat aerodynamic vector nozzle cavity and the plane F1 defined above; its width l x The length L of the expansion section between the first and second throats of the rectangular two-throat aerodynamic vector nozzle is 1 / 9 to 1 / 6; its thickness is l. y For a two-dimensional dual-throat aerodynamic vector nozzle, the throat height H th1 1 / 25 to 1 / 35 of.

[0052] The guide vane shaft should be positioned appropriately, with its axis passing through the 1 / 2 thickness plane of the guide vane and located between the six-divided plane and the three-divided plane on the width of the guide vane. Specifically, the distance between the axis of rotation, the intersection of the 1 / 2 thickness plane, and the sidewall of the guide vane should be 1 / 6 of the plane's width. x ~1 / 3l x .

[0053] To ensure the stability of the flow field by the mechanism when the nozzle is in a non-vector state, the distance x between the rotation axes of adjacent guide vanes and the width l of the guide vanes are... x equal.

[0054] To ensure the proper functioning of the flow field stabilization mechanism, a servo control mechanism is required to control two sets of guide vane arrays separately, enabling the guide vanes in each array to operate in tandem. During operation, each set of guide vanes can rotate around its fixed axis I through an angle of equal magnitude and direction. Based on the rotation angle of the guide vanes, the operating modes of each set of guide vane arrays are divided into two types: closed and open. In the closed state, the same set of guide vanes is in a coplanar state; in the open state, the same set of guide vanes rotates around its axis through a certain angle in the direction of decreasing angle with the wall of the expansion section of the double-throat aerodynamic vector nozzle cavity. This angle is defined as the opening angle δ. max For the maximum opening angle, δ max When β ± 3° and δ = 0°, the guide vane array is in a closed state.

[0055] The rectangular two-dimensional dual-throat aerodynamic vector nozzle operates in two states: non-vector and vector. In the non-vector state, there is no disturbance at the first throat. After the main stream passes through the first throat, it enters the expansion section. Due to entrainment, a reflux zone is formed in the cavity between the first and second throats, causing disturbance to the main stream. In the vector state, the main stream is disturbed on one side of the first throat through means such as micro-jet. After the main stream enters the cavity, the disturbance effect is amplified by the wall on one side before it exits from the second throat, forming a reflux zone on the other side, which also disturbs the main stream.

[0056] Corresponding to the two operating modes of the dual-throat aerodynamic vector nozzle—vectoring and non-vectoring states—this flow field stabilization mechanism employs the following control method:

[0057] When the nozzle is in a non-vectoring state, the servo control mechanism controls the two sets of guide vane arrays to keep them both in a closed state.

[0058] When the nozzle is in a vectoring state, taking upward vectoring as an example, a disturbance is applied to the upper side of the throat. The servo control mechanism controls the upper guide vane array to be in a closed state and controls the lower guide vane array to be in an open state. The opening angle δ increases with the increase of the disturbance intensity, but does not exceed the maximum opening angle δ. max The vector deflection is the opposite.

[0059] like Figure 5 , 6 As shown, as an improvement of the present invention, each group of guide vane arrays can be composed of 2 to 5 guide vanes.

[0060] To ensure that the guide vanes act on the first 1 / 3 to 1 / 2 of the expansion section of the dual-throat aerodynamic vector nozzle, the cross-sectional profile of the guide vanes is modified, making the guide vane width l x The number of guide vanes n in each group and the cavity length L satisfy the following relationship: n·l x= (0.33~0.50)×L.

[0061] like Figure 7 As shown, as an improvement of the present invention, in order to improve the flow performance of the guide vane, the cross-sectional profile of the guide vane can use a corresponding airfoil.

[0062] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle, characterized in that, It includes a first guide vane group (2) arranged above the inside of the double-throat aerodynamic vector nozzle and a second guide vane group (3) arranged below the inside of the double-throat aerodynamic vector nozzle. The first guide vane group (2) and the second guide vane group (3) are symmetrically distributed and are controlled by servo mechanisms respectively. The first guide vane group (2) and the second guide vane group (3) each contain several individual guide vanes. Each of the several guide vanes has a rotating shaft on one side. The several guide vanes rotate around the rotating shaft under the control of the same servo mechanism to open or close.

2. The flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle according to claim 1, characterized in that, The cross-section of the guide vane is a parallelogram, and the length of the base of the cross-section of the guide vane is l. x The length L of the cavity between the first and second throats of the dual-throat aerodynamic vector nozzle is 1 / 9 to 1 / 6; the height l of the cross-section of the guide vane is... y The throat height H of a dual-throat aerodynamic vector nozzle th1 1 / 25 to 1 / 35; without considering the clearance required for rotation, the length l of the guide vane z The distance between the two sidewalls of the dual-throat aerodynamic vector nozzle is equal.

3. The flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle according to claim 2, characterized in that, The cross-section of the guide vane also includes an airfoil, and the types of airfoils include plano-convex, symmetrical, concave-convex, S-shaped, biconvex, and special types.

4. The flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle according to claim 1, characterized in that, The first guide vane group (2) and the second guide vane group (3) are both composed of 2 to 5 guide vanes; in order to ensure that the guide vanes act on the first 1 / 3 to 1 / 2 of the expansion section between the first and second throats of the double-throat aerodynamic vector nozzle, the bottom edge length l of the cross-section of the guide vane is... x The number of guide vanes n in each guide vane group and the cavity length L satisfy the following relationship: n·l x = (0.33~0.50)×L.

5. The flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle according to claim 1, characterized in that, To ensure the rotational capability of the guide vanes, a rotating shaft is provided on one side of each guide vane. The plane formed by the axes of multiple rotating shafts coincides with the plane formed by half the height of the guide vane's cross-section. The intersection line of the plane formed by half the height of the guide vane's cross-section and the short side of the guide vane's cross-section is obtained. The distance between the axis of the rotating shaft and the intersection line is 1 / 6l. x ~1 / 3l x .

6. The flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle according to claim 1, characterized in that, For the first guide vane group (2), the multiple rotating shafts it contains are all coplanar and are all located on the plane F1 defined by the line connecting the upper edge of the first throat and the upper edge of the second throat; for the second guide vane group (3), the multiple rotating shafts it contains are all coplanar and are all located on the plane F2 defined by the lower edge of the first throat and the lower edge of the second throat.

7. The flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle according to claim 5, characterized in that, For the first guide vane group (2) and the second guide vane group (3), the distance x between the rotating shafts of adjacent guide vanes is 1 / 9 to 1 / 6 of the cavity length L between the first and second throats of the double-throat aerodynamic vector nozzle, that is, the distance x between the rotating shafts of adjacent guide vanes is equal to the width l of the guide vanes. x equal.

8. The flow field stabilization mechanism for a dual-throat aerodynamic vector nozzle according to claim 1, characterized in that, The servo control mechanism is located outside the dual-throat aerodynamic vector nozzle and controls the first guide vane group (2) and the second guide vane group (3) respectively. The servo mechanism also controls the same group of guide vanes to have the same opening angle δ.

9. A control method for a flow field stabilization mechanism of a dual-throat aerodynamic vector nozzle according to claim 1, characterized in that, The first guide vane group (2) and the second guide vane group (3) have two working states: open and closed. In the open state, the guide vanes of both the first guide vane group (2) and the second guide vane group (3) rotate around the axis of rotation through an angle δ toward the center of the double-throat aerodynamic vector nozzle. δ is defined as follows: max Maximum opening angle: δ max =β±3°; β is the contraction angle of the contraction section of the dual-throat nozzle; When δ = 0°, the first guide vane group (2) and the second guide vane group (3) are in a closed state.

Images