阅读说明：本技术 基于准轴对称喉道偏移式气动矢量喷管的旋转垂直起降喷管及其设计方法 (Rotary vertical take-off and landing spray pipe based on quasi-axisymmetric throat offset type pneumatic vectoring spray pipe and design method thereof ) 是由 黄帅 徐惊雷 宋光韬 潘睿丰 张玉琪 陈匡世 曹明磊 成前 于 2020-09-17 设计创作，主要内容包括：本发明公开了一种基于准轴对称喉道偏移式气动矢量喷管的旋转垂直起降喷管及其设计方法。旋转垂直起降喷管包括固定筒体段、第一旋转筒体段、第二旋转筒体段；第一旋转筒体段的前端能够相对于固定筒体段的尾部旋转连接,并与第一旋转驱动机构的作动端连接；第二旋转筒体段的前端能够相对于第一旋转筒体段的尾部旋转连接,并与第二旋转驱动机构的作动端连接。平飞模态下,本喷管内流道为典型的准轴对称喉道偏移式气动矢量喷管的双喉道结构,通过在一喉道附近有源、无源的气动扰动或者机械扰动。垂直起降模态下,通过第一、二两段旋转筒体段的旋转,使得喷管出口变为倾斜向下,并在一喉道附近扰动的施加下,实现喷管出口气流90°以上转向。(The invention discloses a rotary vertical take-off and landing spray pipe based on a quasi-axisymmetric throat offset type pneumatic vectoring spray pipe and a design method thereof. The rotary vertical lifting spray pipe comprises a fixed cylinder section, a first rotary cylinder section and a second rotary cylinder section; the front end of the first rotary cylinder section can be rotationally connected relative to the tail of the fixed cylinder section and is connected with the actuating end of the first rotary driving mechanism; the front end of the second rotary cylinder section can be rotationally connected relative to the tail of the first rotary cylinder section and is connected with the actuating end of the second rotary driving mechanism. In a flat flying mode, the inner flow passage of the spray pipe is of a double-throat structure of a typical quasi-axisymmetric throat offset type pneumatic vectoring spray pipe, and active and passive pneumatic disturbance or mechanical disturbance is carried out near one throat. In the vertical take-off and landing mode, the outlet of the spray pipe is inclined downwards through the rotation of the first and second sections of rotating cylinder sections, and the airflow at the outlet of the spray pipe is turned over by more than 90 degrees under the action of disturbance near a throat.)

1. A rotary vertical take-off and landing spray pipe based on a quasi-axisymmetric throat offset type pneumatic vectoring spray pipe comprises a spray pipe body; the main structure of the nozzle body is a quasi-axisymmetric double-throat offset pneumatic vector nozzle which comprises a throat and two throats, wherein an auxiliary thrust vector mechanism is arranged at the position of the throat of the nozzle body, the nozzle body between the throat and the two throats forms a cavity part in an inner flow channel of the nozzle body by arranging two throat front expansion and convergence sections, and the two throat front expansion and convergence sections comprise two throat front expansion sections and two throat front convergence sections which are arranged in the forward direction; the jet pipe is characterized in that the jet pipe body comprises a fixed cylinder section, a first rotating cylinder section and a second rotating cylinder section which are sequentially arranged along the flow direction of fluid;

the front end of the first rotary cylinder section can be rotationally connected relative to the tail of the fixed cylinder section and is connected with the actuating end of the first rotary driving mechanism; the connecting plane K1 between the front end of the first rotary cylinder section and the tail of the fixed cylinder section is positioned at the front section part of the front expansion section of the two throats adjacent to the throat; the cross section shape of a flow channel of the front end of the first rotating cylinder section in a vertical flow direction is an elliptical cross section, the tail part of the fixed cylinder section is provided with a spray pipe transition connection section a matched with the front end of the first rotating cylinder section, and the cross section shape of the flow channel of the spray pipe transition connection section a is smoothly transited from a circular cross section to an elliptical cross section along the flow direction of fluid;

the front end of the second rotary cylinder section can be rotationally connected relative to the tail part of the first rotary cylinder section and is connected with the actuating end of the second rotary driving mechanism, and a connecting plane K2 between the rear end of the first rotary cylinder section and the front end of the second rotary cylinder section is positioned at the rear section position where the front expansion section of the two throats is adjacent to the front convergence section of the two throats; the flow passage section shape of the rear end of the first rotary cylinder section is an elliptical section, the front end of the second rotary cylinder section is provided with a spray pipe transition connection section b matched with the rear end of the first rotary cylinder section, and the flow passage section shape of the spray pipe transition connection section b is smoothly transited from the elliptical section to a circular section along the fluid flow direction.

2. The rotary VTOL nozzle based on the quasi-axisymmetric throat offset pneumatic vectoring nozzle of claim 1, wherein the axes of the stationary barrel section, the first rotary barrel section and the second rotary barrel section are collinear when the nozzle body is in a flat flight state, and the normal of the junction plane K2 between the rear end of the first rotary barrel section and the front end of the second rotary barrel section is in the horizontal plane;

when the nozzle body is in a vertical lifting state, under the action of the first and second rotary driving mechanisms, the normal line of a connecting plane K1 of the first rotary cylinder section is enabled to deflect relative to the axis of the fixed cylinder section, and the normal line of a connecting plane K2 of the second rotary cylinder section is enabled to deflect relative to the axis of the first rotary cylinder section until the outlet axis of the nozzle body is obliquely and downwards arranged relative to the axis of the fixed cylinder section, and meanwhile, the auxiliary thrust vector applied by the auxiliary thrust vector mechanism is matched, so that the outlet airflow of the nozzle can achieve steering of more than 90 degrees.

3. The rotary vtol nozzle of claim 1 based on a quasi-axisymmetric throat-offset aerodynamic vectoring nozzle, wherein the forward end of the first rotary cylinder section is rotatably connected to the aft end of the stationary cylinder section by a bearing a; the front end of the second rotary cylinder section forms rotary connection with the tail part of the first rotary cylinder section through a bearing b.

4. The rotary vtol nozzle of claim 1 in which the normal to the interface plane K1 between the first rotary cylinder section and the stationary cylinder section is parallel to the axis of the stationary cylinder section when the nozzle body is in a flat flight condition; when the nozzle body is in a vertical lifting state, an included angle between the normal of a connecting plane K1 between the first rotating cylinder section and the fixed cylinder section and the axis of the nozzle body, and an included angle between the normal of a connecting plane K2 between the first rotating cylinder section and the second rotating cylinder section and the axis of the nozzle body are both alpha, and alpha is larger than or equal to 27.5 degrees.

5. The rotary VTOL nozzle of claim 5, wherein the included angle α is selected from the group consisting of: alpha is more than or equal to 27.5 degrees and less than or equal to 37.5 degrees.

6. The design method of the rotary vertical take-off and landing nozzle based on the quasi-axisymmetric throat offset aerodynamic vectoring nozzle of claim 1, characterized by comprising the following steps:

selecting a reference molded line of an axisymmetric throat offset type pneumatic vectoring nozzle;

(2) partitioning the two throat front reference profiles of the selected axisymmetric throat offset aerodynamic vectoring nozzle, wherein: according to the fluid flow direction, flow channel section molded lines BB ', CC ', DD ', EE ' and FF ' are sequentially set between a throat section molded line AA ' and a two throat section molded line GG ' of the selected axisymmetric throat offset pneumatic vectoring nozzle;

the region between the flow channel section molded line AA 'and the flow channel section molded line BB' is set as the position of disturbance injection of the spray pipe;

the region between the flow channel section molded line BB 'and the flow channel section molded line CC' is set as a joint plane K₁And the design position of the mounting bearing a;

the region between the flow channel section molded line CC 'and the flow channel section molded line DD' is set as the design position of a nozzle transition connecting section a;

the region between the flow channel section molded line DD 'and the flow channel section molded line EE' is set as a joint plane K₂And the design position of the mounting bearing b;

the region between the flow channel section molded line EE 'and the flow channel section molded line FF' is set as the design position of a nozzle transition connecting section b;

(3) determining a complete axisymmetric partial profile, a partial profile with an elliptical cross section in the flow direction and a transition profile between the two of the nozzle and the partial profile based on the partition of the step (2);

(4) determining a joining plane K between the stationary cylinder and the first rotating cylinder based on the above-mentioned zoning and profile characteristics₁And a connection plane K between the first rotary cylinder and the second rotary cylinder₂；

(5) Perfecting the joining plane K₁And a joining plane K₂Of nearby bearings, rotary drive mechanismsDesigning;

(6) and the design of disturbance components near the front expansion and convergence sections of the first throat and the second throat is perfected.

7. The design method of rotary VTOL nozzle based on quasi-axisymmetric throat offset aerodynamic vectoring nozzle of claim 6, characterized in that the distance between the flow cross-section profile AA 'and the flow cross-section profile BB' is not longer than 1/4 of the front divergent convergent section of the two throats and not shorter than 1/10 of the front divergent convergent section of the two throats;

the length of the transition connection section a of the spray pipe is not shorter than 1.5 times of the difference between the major axis and the minor axis of the section ellipse of the section molded line DD' of the flow channel;

the length of the nozzle transition connecting section b is not shorter than 1 time of the difference between the major axis and the minor axis of the section ellipse of the flow channel section molded line EE'.

8. The design method of the rotary VTOL nozzle based on the quasi-axisymmetric throat offset pneumatic vectoring nozzle of claim 7, wherein the planes on which the flow passage section molded line DD 'and the flow passage section molded line EE' are located are elliptical surfaces; the molded surface between the runner section molded line DD 'and the runner section molded line EE' is an elliptic conical surface;

major axis a of ellipse at the plane of the flow channel cross-section profile DD_DAnd minor axis b_DRatio of (a) to the major axis a of the ellipse at the plane of the profile line EE' of the cross-section of the flow channel_EAnd minor axis b_EThe ratio of (A) is consistent, is recorded as m, namely: m = b_D/a_D= b_E/a_E；

Joining plane K₁Angle with the axis of the nozzle, joining plane K₂The included angle between the nozzle and the axis of the spray pipe is alpha, and the following requirements are met: cos α = m = b_D/a_D=b_E/a_E；

The convergence angle of the front convergence section of the second throat of the axisymmetric throat offset pneumatic vectoring nozzle with the typical configuration is beta; under the vertical take-off and landing mode, for the condition that no disturbance is applied to the lower portion of a throat, the vector angle generated by the nozzle body is changed into delta after the disturbance is applied to the lower portion of the throat, and an included angle alpha exists between the normal of the plane where the tail portion of the second rotating cylinder is located and the axial direction of the nozzle, so that under the vertical take-off and landing mode, the convergence angle beta, the vector angle delta and the included angle alpha of the nozzle body meet the following requirements: 2 alpha + n beta + delta is more than or equal to 95 degrees; beta is more than or equal to 35 degrees and less than or equal to 50 degrees, n is more than or equal to 0.5 degrees and less than or equal to 0.75 degrees, delta is more than or equal to 15 degrees and less than or equal to 25 degrees, and alpha is more than or equal to 27.5 degrees.

9. The method of claim 8 wherein in the VTOL mode, α is 27.5 ° or more and 37.5 ° or less.

10. The design method of the rotary VTOL nozzle based on the quasi-axisymmetric throat offset pneumatic vectoring nozzle of claim 6, wherein the upstream nozzle profile of the channel section profile CC 'and the downstream nozzle profile of the channel section profile FF' are both rotated around the central axis according to the nozzle typical profile result; the molded surface between the runner section molded line DD 'and the runner section molded line EE' is an elliptic conical surface; the molded surface between the flow channel section molded line CC 'and the flow channel section molded line DD' is a circular section and is in smooth transition to an elliptical section, and the molded surface between the flow channel section molded line EE 'and the flow channel section molded line FF' is an elliptical section and is in smooth transition to a circular section.

Technical Field

The invention designs a rotary vertical take-off and landing spray pipe based on a quasi-axisymmetric throat offset type pneumatic vectoring spray pipe and a design method thereof, belonging to the technical field of advanced thrust vectoring spray pipes of aircraft engines.

Background

With the development of scientific technology and urgent needs in practical application, the short-range/vertical take-off and landing aircraft enters the visual field of people again. The traditional short-distance/vertical take-off and landing spray pipe is complex in structure, difficult to control in the mode switching process and difficult to maintain. Therefore, there is a need for a short-reach/vertical-take-off exhaust system that is simple in construction, light in weight, and capable of meeting the high-speed flight requirements.

At present, the fluid thrust vectoring nozzle gradually becomes a research focus and a research hotspot of each country by the characteristics of simple structure and light weight, and will enter engineering application in the near future. Among them, the throat offset pneumatic thrust vectoring nozzle is a new type of fluid thrust vectoring nozzle which has been developed in recent years, and is more and more favored by virtue of the characteristics of simple structure, light weight, good vectoring performance and the like. The common throat offset pneumatic vectoring nozzle is of a double-throat structure, and the area of two throats is slightly larger than that of one throat, which is the most common. The function of the engine is realized in the principle that the disturbance applied to one throat deflects the speed section of the airflow at the throat, and then the disturbance is amplified in the expansion and convergence section at the front of the two throats to generate a stable thrust vector. The throat offset pneumatic vector nozzle can be generally divided into an active type and a self-adaptive passive type, wherein the source of an air source for generating a thrust vector by the active type is mostly an external compressor, an air bottle or air introduced from a high-pressure part (mostly an air compressor) of an aeroengine, and the throat offset pneumatic vector nozzle is characterized in that the thrust vector angle changes little along with the working pressure drop ratio of the nozzle, but the thrust loss of the whole aeroengine is large; the self-adaptive passive type is characterized in that a self-adaptive bypass channel is arranged to guide high-pressure airflow at the inlet position of the spray pipe to the designated position of the spray pipe for injection, self-adaptively generates disturbance and finally realizes a thrust vector. In recent years, a mechanical disturbance type also becomes one of disturbance sources generated by the vectors of the nozzle pipes, the mechanism of the vector generation is consistent with that of pneumatic disturbance, the disturbance source is only changed into a mechanical disturbance piece from air flow, the problems that the thrust vector angle is reduced along with the increase of the working pressure drop ratio of the traditional throat offset type pneumatic vector nozzle which generates disturbance by injecting air flow can be solved, and the problem that the matching of the nozzle pipe and an aircraft control system is greatly simplified because the vector angle is fixed under the condition that the rotation-out angle of the mechanical disturbance piece is fixed regardless of the change of the working pressure drop ratio of the nozzle pipe.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art, the rotary vertical take-off and landing spray pipe based on the quasi-axisymmetric throat offset type pneumatic vectoring spray pipe disclosed by the invention utilizes the geometric property of an elliptical cone, two bearings are arranged at special positions in a special concave cavity of the quasi-axisymmetric throat offset type pneumatic vectoring spray pipe, and the molded surface of the concave cavity of a part is driven to rotate under the control of a servo mechanism, so that the vertical take-off and landing function is realized. Under the vertical take-off and landing mode, the outlet of the spray pipe is inclined downwards, disturbance is applied to airflow near one throat of the quasi-axisymmetric throat offset type pneumatic vector spray pipe, and control of the aircraft under the hovering posture is completed; in a flat flying mode, the outlet of the spray pipe faces backwards, disturbance is applied to airflow near one throat of the quasi-axisymmetric throat offset type pneumatic vectoring spray pipe, the pitching and yawing postures of the aircraft are controlled, and therefore the maneuverability of the aircraft is improved.

The technical scheme is as follows: in order to achieve the purpose, the invention adopts the technical scheme that:

a rotary vertical take-off and landing spray pipe based on a quasi-axisymmetric throat offset type pneumatic vectoring spray pipe comprises a spray pipe body; the main structure of the nozzle body is a quasi-axisymmetric double-throat offset pneumatic vector nozzle which comprises a throat and two throats, wherein an auxiliary thrust vector mechanism is arranged at the position of the throat of the nozzle body, the nozzle body between the throat and the two throats forms a cavity part in an inner flow channel of the nozzle body by arranging two throat front expansion and convergence sections, and the two throat front expansion and convergence sections comprise two throat front expansion sections and two throat front convergence sections which are arranged in the forward direction; the nozzle body comprises a fixed cylinder section, a first rotating cylinder section and a second rotating cylinder section which are sequentially arranged along the flow direction of fluid;

the front end of the first rotary cylinder section can be rotationally connected relative to the tail of the fixed cylinder section and is connected with the actuating end of the first rotary driving mechanism; the connecting plane K1 between the front end of the first rotary cylinder section and the tail of the fixed cylinder section is positioned at the front section part of the front expansion section of the two throats adjacent to the throat; the cross section of a flow channel in the vertical flow direction at the front end of the first rotating cylinder section is in an elliptical cross section, the tail part of the fixed cylinder section is provided with a spray pipe transition connection section a matched with the front end of the first rotating cylinder section, and the cross section of the flow channel of the spray pipe transition connection section a is in smooth transition from a circular cross section to an elliptical cross section along the flow direction of fluid;

the front end of the second rotary cylinder section can be rotationally connected relative to the tail part of the first rotary cylinder section and is connected with the actuating end of the second rotary driving mechanism, and a connecting plane K2 between the rear end of the first rotary cylinder section and the front end of the second rotary cylinder section is positioned at the rear section position where the front expansion section of the two throats is adjacent to the front convergence section of the two throats; the flow passage section shape of the rear end of the first rotary cylinder section is an elliptical section, the front end of the second rotary cylinder section is provided with a spray pipe transition connection section b matched with the rear end of the first rotary cylinder section, and the flow passage section shape of the spray pipe transition connection section b is smoothly transited from the elliptical section to a circular section along the fluid flow direction.

Preferably, when the nozzle body is in a flat flight state, the axes of the fixed cylinder section, the first rotating cylinder section and the second rotating cylinder section are collinear, and the normal line of a joint plane K2 between the rear end of the first rotating cylinder section and the front end of the second rotating cylinder section is located in a horizontal plane;

when the nozzle body is in a vertical lifting state, under the action of the first and second rotary driving mechanisms, the normal line of a connecting plane K1 of the first rotary cylinder section is enabled to deflect relative to the axis of the fixed cylinder section, and the normal line of a connecting plane K2 of the second rotary cylinder section is enabled to deflect relative to the axis of the first rotary cylinder section until the outlet axis of the nozzle body is obliquely and downwards arranged relative to the axis of the fixed cylinder section, and meanwhile, the auxiliary thrust vector applied by the auxiliary thrust vector mechanism is matched, so that the outlet airflow of the nozzle can achieve steering of more than 90 degrees.

Preferably, the front end of the first rotary cylinder section forms a rotary connection with the tail part of the fixed cylinder section through a bearing a; the front end of the second rotary cylinder section forms rotary connection with the tail part of the first rotary cylinder section through a bearing b.

Preferably, when the nozzle body is in a flat flight state, the normal of the interface plane K1 between the first rotary cylinder section and the stationary cylinder section is parallel to the axis of the stationary cylinder section; when the nozzle body is in a vertical lifting state, an included angle between the normal of a connecting plane K1 between the first rotating cylinder section and the fixed cylinder section and the axis of the nozzle body, and an included angle between the normal of a connecting plane K2 between the first rotating cylinder section and the second rotating cylinder section and the axis of the nozzle body are both alpha, and alpha is larger than or equal to 27.5 degrees.

Preferably, the included angle α has a value range of: alpha is more than or equal to 27.5 degrees and less than or equal to 37.5 degrees.

The invention also aims to provide a design method of the rotary vertical take-off and landing nozzle based on the quasi-axisymmetric throat offset type pneumatic vectoring nozzle, which comprises the following steps:

(1) selecting a reference molded line of an axisymmetric throat offset type pneumatic vectoring nozzle;

(2) partitioning the two throat front reference profiles of the selected axisymmetric throat offset aerodynamic vectoring nozzle, wherein: according to the fluid flow direction, flow channel section molded lines BB ', CC ', DD ', EE ' and FF ' are sequentially set between a throat section molded line AA ' and a two throat section molded line GG ' of the selected axisymmetric throat offset pneumatic vectoring nozzle;

the region between the flow channel section molded line AA 'and the flow channel section molded line BB' is set as the position of disturbance injection of the spray pipe;

the region between the flow channel section molded line BB 'and the flow channel section molded line CC' is set as a joint plane K₁And the design position of the mounting bearing a;

the region between the flow channel section molded line CC 'and the flow channel section molded line DD' is set as the design position of a nozzle transition connecting section a;

the region between the flow channel section molded line DD 'and the flow channel section molded line EE' is set as a joint plane K₂And the design position of the mounting bearing b;

the region between the flow channel section molded line EE 'and the flow channel section molded line FF' is set as the design position of a nozzle transition connecting section b;

(3) determining a complete axisymmetric partial profile, a partial profile with an elliptical cross section in the flow direction and a transition profile between the two of the nozzle and the partial profile based on the partition of the step (2);

(4) determining a joining plane K between the stationary cylinder and the first rotating cylinder based on the above-mentioned zoning and profile characteristics₁And a connection plane K between the first rotary cylinder and the second rotary cylinder₂；

(5) Perfecting the joining plane K₁And a joining plane K₂Designing a nearby bearing and a rotary driving mechanism;

(6) and the design of disturbance components near the front expansion and convergence sections of the first throat and the second throat is perfected.

Preferably, the distance between the flow passage section molded line AA 'and the flow passage section molded line BB' is not longer than 1/4 of the front expanding and converging section of the two throats and not shorter than 1/10 of the front expanding and converging section of the two throats;

the length of the transition connection section a of the spray pipe is not shorter than 1.5 times of the difference between the major axis and the minor axis of the section ellipse of the section molded line DD' of the flow channel;

the length of the nozzle transition connecting section b is not shorter than 1 time of the difference between the major axis and the minor axis of the section ellipse of the flow channel section molded line EE'.

Preferably, the planes of the flow channel section molded line DD 'and the flow channel section molded line EE' are elliptical surfaces; the molded surface between the runner section molded line DD 'and the runner section molded line EE' is an elliptic conical surface;

major axis a of ellipse at the plane of the flow channel cross-section profile DD_DAnd minor axis b_DRatio of (a) to the major axis a of the ellipse at the plane of the profile line EE' of the cross-section of the flow channel_EAnd minor axis b_EThe ratio of (A) is consistent, is recorded as m, namely: m = b_D/a_D= b_E/a_E；

Joining plane K₁Angle with the axis of the nozzle, joining plane K₂The included angle between the nozzle and the axis of the spray pipe is alpha, and the following requirements are met: cos α = m = b_D/a_D=b_E/a_E；

The convergence angle of the front convergence section of the second throat of the axisymmetric throat offset pneumatic vectoring nozzle with the typical configuration is beta; under the vertical take-off and landing mode, for the condition that no disturbance is applied to the lower portion of a throat, the vector angle generated by the nozzle body is changed into delta after the disturbance is applied to the lower portion of the throat, and an included angle alpha exists between the normal of the plane where the tail portion of the second rotating cylinder is located and the axial direction of the nozzle, so that under the vertical take-off and landing mode, the convergence angle beta, the vector angle delta and the included angle alpha of the nozzle body meet the following requirements: 2 alpha + n beta + delta is more than or equal to 95 degrees; beta is more than or equal to 35 degrees and less than or equal to 50 degrees, n is more than or equal to 0.5 degrees and less than or equal to 0.75 degrees, delta is more than or equal to 15 degrees and less than or equal to 25 degrees, and alpha is more than or equal to 27.5 degrees.

Preferably, in the vertical take-off and landing mode, the angle alpha is more than or equal to 27.5 degrees and less than or equal to 37.5 degrees.

Preferably, the upstream nozzle profile of the flow passage section profile line CC 'and the downstream nozzle profile of the flow passage section profile line FF' are both formed by rotating around the central axis according to a typical profile result of the nozzle; the molded surface between the runner section molded line DD 'and the runner section molded line EE' is an elliptic conical surface; the molded surface between the flow channel section molded line CC 'and the flow channel section molded line DD' is a circular section and is in smooth transition to an elliptical section, and the molded surface between the flow channel section molded line EE 'and the flow channel section molded line FF' is an elliptical section and is in smooth transition to a circular section.

Has the advantages that: compared with the prior art, the rotary vertical take-off and landing nozzle with the short-distance/vertical take-off and landing function based on the quasi-axisymmetric throat offset type pneumatic vectoring nozzle has the following advantages:

(1) compared with the traditional three-bearing vertical take-off and landing spray pipe, the scheme reduces the number of parts and the adjustment complexity to a certain extent, improves the control precision and the response speed of the spray pipe by virtue of the characteristics of high response speed and omnidirectional vector of the axisymmetric pneumatic vector spray pipe, and provides guarantee for the use of aircrafts under special conditions such as strong crosswind and the like;

(2) the scheme is insensitive to the pneumatic vectoring nozzle, namely no matter what disturbance source of vector generated by air flow of the nozzle is, the scheme can be combined with accessories such as a mechanical steering section and the like in the invention as long as a corresponding rotating angle can be realized, and a corresponding vertical lifting function is realized.

(3) Compared with other types of vertical take-off and landing nozzles, the vertical take-off and landing nozzle is lighter in weight, less in driving mechanical structure, small in size, and higher in size, weight and reliability of rotating parts.

(4) Other modifications of the throat offset pneumatic thrust vectoring nozzle can be combined with the scheme, so that the throat offset pneumatic thrust vectoring nozzle has multiple functions on one set of mechanism, such as low detectability, reverse thrust and the like.

Drawings

FIG. 1 is a sectional schematic view of a reference profile of an offset aerodynamic vectoring nozzle based on an axisymmetric throat;

FIG. 2 is a schematic diagram of the main structure of the horizontal flying mode internal flow channel of the present invention

FIG. 3 is a top view of the flying die of the present invention;

FIG. 4 is a front view of a level flight mode of the present invention;

FIG. 5 is an isometric view of a VTOL mode of the present invention;

FIG. 6 is a front view of a VTOL mode of the present invention;

FIG. 7 is a schematic top view of a VTOL mode of the present invention;

FIG. 8a is a flow field diagram of the present invention when no disturbance is applied;

fig. 8b is a flow field diagram of the present invention when mechanical disturbance is applied.

The figure includes: 11. equal straight section 12, a throat front convergence section 13, a throat 21, two throat front expansion sections 31, two throat front convergence sections 32, and two throats (outlets).

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

Therefore, the rotary vertical take-off and landing nozzle based on the quasi-axisymmetric throat offset type pneumatic vectoring nozzle provided by the invention utilizes the geometric property of an elliptical cone, and drives partial concave cavity profiles to rotate under the control of a servo mechanism by arranging two bearings at special positions in the concave cavity of the special profiles of the quasi-axisymmetric throat offset type pneumatic vectoring nozzle, thereby realizing the vertical take-off and landing function. Under the horizontal flight mode and the vertical take-off and landing mode, the quasi-axisymmetric throat offset type pneumatic vectoring nozzle still uses the original thrust vector generation mode to realize deflection of airflow and complete control of the attitude of the aircraft under the two modes. Through the means, the spray pipe has the thrust vector auxiliary high maneuverability and the efficient, reliable and portable vertical take-off and landing capability, and the mode switching process is reliable and controllable.

Specifically, as shown in fig. 1 to 7, the rotary vertical lift nozzle based on the quasi-axisymmetric throat offset aerodynamic vectoring nozzle of the present invention includes a main body of the quasi-axisymmetric throat offset aerodynamic vectoring nozzle, two bearings installed at specific positions in a cavity, an actuating mechanism for driving a nozzle barrel to rotate around the bearings, and a related mechanism or structure (auxiliary thrust vectoring mechanism) for applying disturbance to a main flow in the nozzle near a throat. In a flat flying mode, the inner flow passage of the jet pipe is of a double-throat structure of a typical quasi-axisymmetric throat offset type pneumatic vectoring jet pipe, and a thrust vector for assisting high maneuvering flight of an aircraft is generated through active and passive pneumatic disturbance or mechanical disturbance near one throat. In the vertical lifting mode, the second section of the rotary spray pipe barrel and the third section of the rotary spray pipe barrel are driven by the actuating mechanism, so that the outlet of the spray pipe is changed from horizontal backward in the flat flying mode to inclined downward, and the airflow at the outlet of the spray pipe is turned by more than 90 degrees under the action of disturbance near a throat.

The main nozzle inner flow channel structure based on the rotary vertical take-off and landing nozzle flat flight mode of the quasi-axisymmetric throat offset type aerodynamic vectoring nozzle is consistent with that of a common quasi-axisymmetric throat offset type aerodynamic vectoring nozzle, and comprises an equal straight section 11, a throat front convergence section 12, a throat 13, two throat front expansion convergence sections (concave cavities) and two throats 32 (nozzle outlets), wherein the two throat front expansion convergence sections comprise two throat front expansion sections 31 and two throat front convergence sections 32. Under the vertical lifting mode, part of the spray pipe barrel body with the structure is rotated under the action of the driving mechanism, so that the vertical lifting function is realized. Specifically, the rotary vertical take-off and landing nozzle based on the quasi-axisymmetric throat offset type pneumatic vectoring nozzle mainly comprises the following three nozzle profiles:

(1) fixing the cylinder body 1: the main function is to disturb the main flow near the initial section of the front expansion section of the first throat and the second throat by injecting the secondary flow or mechanical disturbance, and generate initial air flow vector deflection so as to improve the maneuverability of the aircraft in a flat flight mode or complete attitude control in a vertical take-off and landing mode and a mode switching process. The tail part of the fixed cylinder body is provided with a bearing, a driving mechanism and other mechanisms which are matched with the first rotary cylinder body, and the plane of the tail part is vertical to the axial direction of the spray pipe.

(2) First rotary cylinder 2: the expansion and convergence section 21 mainly comprising the front part of the second throat (specifically, the expansion section of the front part of the second throat) is one of the key parts for realizing the vertical take-off and landing functions. The initial position of the first rotary cylinder body is provided with a bearing, a driving mechanism and other mechanisms which are matched with the fixed cylinder body, and the plane of the initial position is vertical to the axial direction of the spray pipe. The tail part of the first rotating cylinder body is provided with a bearing, a driving mechanism and other mechanisms which are matched with the first rotating cylinder body, a certain included angle alpha is formed between the normal of the plane where the tail part is located and the axis direction of the spray pipe, and in a horizontal flying mode, the normal of the plane where the tail part is located and the axis of the spray pipe are both in the horizontal plane.

(3) Second rotary cylinder 3: the main part comprises a part of the second throat front expansion and convergence section (specifically, a part of the second throat front expansion section and the whole second throat convergence section 31), and is one of the key parts for realizing the vertical take-off and landing function. And a bearing, a driving mechanism and the like matched with the first rotary cylinder are arranged at the starting position of the second rotary cylinder, a certain included angle alpha is formed between the normal of the plane where the tail part is located and the axial direction of the spray pipe, and in a horizontal flying mode, the normal of the plane where the tail part is located and the axial direction of the spray pipe are both in the horizontal plane.

Therefore, designing a rotary VTOL nozzle of a quasi-axisymmetric throat offset aerodynamic vectoring nozzle may follow the following design steps: (1) selecting a reference molded line of an axisymmetric throat offset pneumatic vectoring nozzle with better performance; (2) partitioning is carried out on the reference molded lines at the front parts of the two throats of the axial symmetric throat offset type pneumatic vectoring nozzle; (3) determining a full axisymmetric partial profile of the nozzle, a partial profile having an elliptical cross-section in the flow direction, and a transition profile therebetween based on the zoning; (4) determining a joint plane K of the fixed cylinder and the first rotary cylinder based on the partition and the molded surface₁And a first rotary cylinder and a second rotary cylinder connecting plane K₂(ii) a (5) Perfecting the joining plane K₁And a joining plane K₂Designing a nearby bearing and a driving mechanism; (6) and the design of disturbance components near the front expansion and convergence sections of the first throat and the second throat is perfected.

Further, a typical throat offset aerodynamic vectoring nozzle profile is sectioned as shown in FIG. 1. Pneumatic device with runner section molded line AA' as throat offsetAnd a throat of the datum line of the vectoring nozzle, and a flow passage section line GG' are two throats (outlets) of the datum line of the throat offset type pneumatic vectoring nozzle. All the zoning is completed in the expanding and converging section at the front part of the two throats. Considering the diversity of disturbance sources of vectors generated by airflow of the throat offset type pneumatic vector nozzle, a region between the flow channel section molded line AA 'and the flow channel section molded line BB' is set as a position for disturbance injection of the nozzle, namely the flow channel section molded line AA 'to the flow channel section molded line BB' are disturbance applying sections. Generally, if the disturbance source of the nozzle is a mechanical disturbance blade, the distance from the flow channel section molded line AA 'to the flow channel section molded line BB' is not longer than 1/4 of the front expansion and convergence section of the two throats, so as to avoid occupying too much space; not shorter than 1/10 of the expanding and converging section of the front part of the two throats so as to obtain better thrust vector performance. If the source of the nozzle disturbance is an external gas source (active type) or a nozzle inlet (passive type), the distance from the flow channel section molded line AA 'to the flow channel section molded line BB' is about 1/10-1/8 of the expansion and convergence section of the front part of the throat. Arranging a connection plane K from the flow channel section molded line BB' to the flow channel section molded line CC₁And a bearing a is installed, the distance from the flow channel section molded line BB ' to the flow channel section molded line CC ' meets the size of a common bearing, and taking the size of a typical scaled nozzle as an example, the diameter of the flow channel section molded line AA ' is about 20mm, and the distance from the flow channel section molded line BB ' to the flow channel section molded line CC ' is about 5-10 mm. For other sizes of nozzles, the design can be made with reference to this ratio and the bearing practice. The length of the transition section (transition connection section a) from the circular section of the nozzle to the elliptical section is determined by the elliptical size of the plane where the flow passage section molded line DD ' is located, generally speaking, the length of the transition section from the flow passage section molded line CC ' to the flow passage section molded line DD ' is not shorter than 1.5 times of the difference between the major axis and the minor axis of the section ellipse where the flow passage section molded line DD ' is located, and the radius of the circular section of the axisymmetric throat offset type pneumatic vector nozzle originally located at the flow passage section molded line DD ' is recorded as r₁. The intermediate profile between the runner section molded line DD 'and the runner section molded line EE' is the key for realizing the function of the nozzle. Overall, runner section line DD 'to runner section line EE'The middle molded surface is a part of an elliptic conical surface, namely the planes of the flow channel section molded line DD ' and the flow channel section molded line EE ' are both elliptic surfaces, and a connecting plane K is arranged between the flow channel section molded line DD ' and the flow channel section molded line EE₂And a bearing b is installed. The length of the transition section (transition connection section b) from the circular section of the nozzle to the elliptical section is determined by the elliptical size of the section where the flow channel section molded line EE ' is located, generally, the length from the flow channel section molded line EE ' to the flow channel section molded line FF ' is not shorter than 1 time of the difference between the major axis and the minor axis of the section ellipse where the flow channel section molded line EE ' is located, and the radius of the circular section of the axisymmetric throat offset type pneumatic vector nozzle originally located at the flow channel section molded line EE ' is r₂。

Further, according to the partitioning result, the nozzle profile upstream of the flow passage section profile CC 'and the nozzle profile downstream of the flow passage section profile FF' are both formed by rotating around the central axis according to the nozzle typical profile result. The molded surface between the flow channel section molded line DD 'and the flow channel section molded line EE' is an elliptic conical surface. The molded surfaces from the runner section molded line CC 'to the runner section molded line DD' and from the runner section molded line EE 'to the runner section molded line FF' are variable section transition sections. Wherein: the molded surface between the flow channel section molded line CC 'and the flow channel section molded line DD' is a variable cross-section transition section of a circular cross section and an elliptical cross section; the molded surface between the runner section molded line EE 'and the runner section molded line FF' is a variable cross section transition section with an elliptical cross section and a circular cross section.

Furthermore, the ellipse at the flow passage section line DD ' and the ellipse at the flow passage section line EE ' are different sections of the same elliptic cone, namely the ellipse major axis a at the flow passage section line DD ' plane_DAnd minor axis b_DRatio of (a) to the ellipse a at the plane of the profile line EE' of the flow channel cross-section_EAnd minor axis b_EThe ratio of (A) is consistent, is recorded as m, namely:

m=b_D/a_D=b_E/a_E

the requirement of low flow loss is met by simple geometric relationship and no sudden expansion and contraction of flow area, and the requirements are met:

π×a_D×b_D=π×r₁ ²and pi x a_E×b_E=π×r₂ ²

And due to the geometrical relationship of the elliptic conical surface, the connecting plane K₂The included angle alpha with the axis of the spray pipe satisfies the following geometrical relation:

cos α=m=b_D/a_D=b_E/a_E

in the vertical take-off and landing mode of the invention, the vector angle of the spray pipe is not less than 95 degrees, the convergence angle of the front convergence section of the two throats of the axisymmetric throat offset type pneumatic vector spray pipe with a typical configuration is beta, and the vector angle generated by the spray pipe after disturbance is applied to the lower part of one throat and the vector angle generated by the spray pipe when disturbance is not applied is delta according to the empirically estimated vertical take-off and landing mode of the spray pipe, the three requirements are satisfied:

2α+nβ+δ≥95°

in the full three-dimensional flow, the change of the thrust vector angle after the airflow is acted by the convergent section of the nozzle is not equal to the convergent angle of the convergent section, and the actual thrust vector change angle is smaller than the convergent angle of the convergent section under most conditions, so that a correction parameter n (n is less than or equal to 1) is set. In general, 35 DEG-beta-50 DEG, the correction parameter 0.5-n 0.75 and 15 DEG-delta-25 deg. Thus, α ≧ 27.5 ℃ is obtained in the usual case. Considering the significant turn of the profile in the nozzle in the VTOL mode, an increase in α will lead to an increase in nozzle thrust loss, and therefore in general, α is 27.5 ° or more and 37.5 ° or less.

Because the invention is based on the transformation of the axisymmetric throat offset type pneumatic thrust vectoring nozzle with a typical configuration, r is₁And r₂Are known parameters. The value of alpha can be given through self-design, and then a is obtained_D、b_D、a_E、b_EThe numerical value of (c).

Further, the cross-over plane K₂It is required to be completely within the elliptical cone, i.e. the intersection of the intersection plane with the conical surface is between EE 'and FF'.

Further, in the flat flying mode, the major axes of the ellipse at the flow passage section molded line DD 'and the ellipse at the flow passage section molded line EE' are both in the vertical direction, and the minor axes are both in the horizontal directionAnd (4) direction. Under the mode of flat flying, the axes of the fixed cylinder, the first rotary cylinder and the second rotary cylinder are collinear, and the plane K for connecting the first rotary cylinder and the second rotary cylinder is₂Is located in the horizontal plane. The main flow is disturbed near a throat only by the nozzle to generate airflow deflection, so that the maneuverability of the aircraft in two directions of pitching and yawing is improved.

Further, in the mode switching process, the second rotating cylinder body rotates oppositely relative to the first rotating cylinder body and the first rotating cylinder body relative to the fixed cylinder body, and the rotating strokes are different. Specifically, the first rotating cylinder rotates 90 degrees relative to the fixed cylinder; and the second rotating cylinder rotates 180 degrees relative to the first rotating cylinder, and the rotation directions of the two cylinders are opposite. In terms of the rotational angular velocity, the angular velocity at which the first rotating cylinder rotates relative to the fixed cylinder is one-half of that at which the second rotating cylinder rotates relative to the first rotating cylinder. Under the control of the motion law, in the mode switching process, the fixed cylinder, the first rotating cylinder and the second rotating cylinder all move in a vertical plane.

Further, in the mode switching process, the mechanism and the component for realizing the disturbance of the spray pipe do not rotate. Therefore, at each position in the mode switching process, the nozzle can be adjusted in the pitching and yawing directions by using a common control rule, and the specific adjustment and control scheme and control method are determined by actual requirements and disturbance sources near a throat of the nozzle. After the mode switching is finished, the spray pipe is in the maximum head lowering state so as to realize the vector angle of the vertical take-off and landing mode exceeding 95 degrees.

Furthermore, the mode of generating the nozzle vector may be pneumatic (active or passive), or mechanical disturbance, and the specific disturbance mode and the control mode thereof are substantially the same as those of the common throat offset pneumatic vectoring nozzle, which is not described herein again. In addition, in the vertical take-off and landing mode, the angle alpha is not suitable to be too large in consideration of the geometrical, engineering realizability and performance conditions, so that the disturbance is required to be applied to the lower side near a throat, and the airflow flowing through the throat flows along the upper wall surface of the spray pipe to generate a total vector angle of not less than 95 degrees.

Furthermore, the nozzle is based on an axisymmetric throat offset type pneumatic vector nozzle, and each section of the nozzle in the vertical flow direction is circular. As a further improvement of the invention, a similar improved design can be carried out on the basis of the throat offset type pneumatic thrust vectoring nozzle with an oval cross section, and the specific design steps are basically consistent with the steps in the foregoing.

Further, the mechanism for driving the cylinder to rotate can be a stepping motor or a servo motor, can also be a hydraulic actuating mechanism, and can also be other types of mechanical structures.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.

Examples

The nozzle is designed for a rotary vertical lift nozzle based on a throat offset aerodynamic vectoring nozzle with a typical configuration.

FIGS. 8a and 8b illustrate embodiments of the use of a mechanically perturbed throat-offset aerodynamic vectoring nozzle. The ratio m = b of the minor axis to the major axis of the conical surface of the configuration_D/a_D=b_E/a_E=0.85, α = arc cos0.85=58.21 °. In fig. 8a, the internal flow field of the nozzle is shown without turbulence near a throat. It can be seen that the air flow of the present invention is now turned about 50 degrees and vertical take-off and landing cannot be achieved. However, when the spoiler is extended to control the low head direction, the vectoring nozzle is caused to deflect the airflow at a larger angle.

Therefore, the invention further optimizes the value of m for a specific configuration through further optimization design, and generates airflow deflection in the low head direction by applying disturbance near a throat in the mode switching and vertical take-off and landing states, and finally realizes the assumption that the airflow deflection exceeds 90 degrees, as shown in fig. 8 b.