阅读说明：本技术 一种自适应高度的柔性延伸喷管 (Flexible extension spray tube with self-adaptive height ) 是由 王革 苏成志 谭敦煌 李德坚 李冬冬 陈磊 王英男 周凌 陈成文 于 2019-10-17 设计创作，主要内容包括：本发明涉及火箭发动机技术领域,具体涉及一种自适应高度的柔性延伸喷管。包括基础段钟型喷管部分、多级钟型延伸段部分,可变约束点部分以及支撑结构部分；其中,基础段钟型喷管部分部分为固定喷管,其一端与火箭发动机相连,一端与多级钟型延伸段部分相连；多级钟型延伸段部分为柔性延伸喷管,处于发射初始状态时为卷起状态,之后随飞行高度升高而展开；可变约束点部分位于柔性延伸喷管上,固定到达既定位置的支撑结构部分；支撑结构部分位于柔性延伸喷管内部,随飞行高度升高而展开。本发明可解决目前单级入轨火箭等工作范围广的火箭工作效率低的问题,使气流始终保持完全膨胀,在任何高度下都处于最佳工作状态。(The invention relates to the technical field of rocket engines, in particular to a flexible extension spray pipe with self-adaptive height. The variable constraint point type pipe joint comprises a base section bell-shaped spray pipe part, a multi-stage bell-shaped extension section part, a variable constraint point part and a support structure part; wherein, the base section bell-shaped spray pipe part is divided into fixed spray pipes, one end of each fixed spray pipe is connected with the rocket engine, and the other end of each fixed spray pipe is connected with the multi-stage bell-shaped extension section part; the multistage bell-shaped extension section part is a flexible extension nozzle, is in a rolling-up state when in an initial launching state, and then is unfolded along with the rise of the flying height; the variable constraint point part is positioned on the flexible extension nozzle and is fixed to the support structure part reaching the set position; the support structure is partially located within the flexible extension nozzle and deploys as the flying height increases. The invention can solve the problem of low working efficiency of the existing single-stage orbit rocket with wide working range, and the like, and the air flow is always kept to be fully expanded and is in the best working state at any height.)

1. The utility model provides a flexible extension spray tube of self-adaptation height which characterized in that: the variable constraint point type pipe joint comprises a base section bell-shaped spray pipe part, a multi-stage bell-shaped extension section part, a variable constraint point part and a support structure part; wherein, the base section bell-shaped spray pipe part is divided into fixed spray pipes, one end of which is connected with the rocket engine and the other end is connected with the multi-stage bell-shaped extension section part; the multistage bell-shaped extension section part is a flexible extension nozzle, is in a rolling-up state when in an initial launching state, and then is unfolded along with the rise of the flying height; the variable constraint point part is positioned on the flexible extension nozzle and is fixed to the support structure part reaching the set position; the support structure is partially located within the flexible extension nozzle and deploys as the flying height increases.

2. A flexible extension spout for adaptive height according to claim 1 wherein: the base segment bell nozzle portion comprising: a nozzle convergent section (1), an upstream transition section (2), a downstream transition section (3) and a basic expansion section (4); the basic section bell-shaped spray pipe part is sequentially provided with a spray pipe convergence section (1), an upstream transition section (2), a downstream transition section (3) and a basic expansion section (4) from left to right along the x axial direction, and all the parts are smoothly connected; the convergent section (1) of the spray pipe is 45 degrees; the arc radius of the upstream transition section (2) is 1.5 times of the throat radius, and the upstream transition section is tangent to the nozzle convergent section (1); the molded surface of the downstream transition section (3) is a quadratic curve, the circular arc radius of the downstream transition section is 0.6 times of the throat radius, and the initial expansion half angle of the spray pipe is 28 degrees; the profile of the basic expansion section (4) is one of polynomial, conical and spline curves, the length of the basic expansion section is obtained by an empirical formula, the initial expansion half angle is 28 degrees, and the final expansion half angle is 6 degrees.

3. A flexible extension spout of adaptive height according to claim 1 or 2, wherein: the multistage bell-shaped extension section part comprises: a flexible extension (5); the profile of the flexible extension section (5) is one of polynomial, conical and spline curves, the flexible extension section is unfolded along with the rise of the flying height, and the final expansion half angle is 6 degrees under different working heights.

4. A flexible extension spout for adaptive height according to claim 3 wherein: the variable constraint point portion comprises: a restraint positioning device (6); the constraint positioning device (6) is positioned inside the flexible extension section (5) and is variable in the x-axis direction, a plurality of constraint points are formed after the flexible extension nozzle is flexibly unfolded, and the deformation dimension of the profile of the flexible extension nozzle at the plurality of constraint points is reduced.

5. An adaptive height flexible extension nozzle as defined in claim 4, wherein: the support structure portion, comprising: a support strip (7); the supporting battens (7) are located inside the flexible extension (5) and their position in the x-axis direction is determined by constraint positioning means (6) providing circumferential, radial and simultaneous circumferential and radial constraint.

Technical Field

The invention relates to the technical field of rocket engines, in particular to a flexible extension spray pipe with self-adaptive height.

Background

Because the effective load of the carrier rocket is limited by the performance of the engine, the research on improving the performance of the engine has never been stopped, and two research directions mainly exist, namely the thrust of the engine is improved by improving the specific impulse of the propellant, and the structural research is carried out, such as designing a nozzle with a larger expansion ratio, and the like.

At present, the existing double-bell-shaped spray pipe is simple in structure, but only can be used for carrying out height compensation on two working states, and the profile change is discontinuous. The profile of the plug type spray pipe is continuously changed, but the difficulty of the complicated structure design is high. The forced bias flow nozzle has simple structure and low cost, but has performance loss under low altitude condition. Compared with other height compensation spray pipes, the flexible variable-structure spray pipe has the advantages of continuously variable area ratio, simple structure, high mass ratio, high specific impulse and high performance. The expansion ratio is fixed in the traditional spray pipe, and the flow field can generate over-expansion and under-expansion phenomena when the flow field deviates from the design height, so that the performance loss of the spray pipe is caused.

The expansion ratio of the flexible extension spray pipe can be adjusted according to the pressure change of the external environment, so that the air flow is always kept to be fully expanded and is in the optimal working state at any height.

Disclosure of Invention

The invention aims to solve the problem of low working efficiency of the existing single-stage in-orbit rocket and other rockets with wide working range, and provides a flexible extension spray pipe with self-adaptive height, which can change the area ratio along with the working height.

The purpose of the invention is realized as follows:

a flexible extension nozzle with self-adaptive height comprises a base section bell-shaped nozzle part, a multi-stage bell-shaped extension section part, a variable constraint point part and a support structure part; wherein, the base section bell-shaped spray pipe part is divided into fixed spray pipes, one end of each fixed spray pipe is connected with the rocket engine, and the other end of each fixed spray pipe is connected with the multi-stage bell-shaped extension section part; the multistage bell-shaped extension section part is a flexible extension nozzle, is in a rolling-up state when in an initial launching state, and then is unfolded along with the rise of the flying height; the variable constraint point part is positioned on the flexible extension nozzle and is fixed to the support structure part reaching the set position; the support structure is partially located within the flexible extension nozzle and deploys as the flying height increases.

The invention also includes such structural features:

1. a base segment bell nozzle portion comprising: a nozzle convergent section 1, an upstream transition section 2, a downstream transition section 3 and a basic expansion section 4; the basic section bell-shaped spray pipe part is sequentially provided with a spray pipe convergence section 1, an upstream transition section 2, a downstream transition section 3 and a basic expansion section 4 from left to right along the x axial direction, and all the parts are smoothly connected; the nozzle convergent section 1 is 45 degrees; the arc radius of the upstream transition section 2 is 1.5 times of the throat radius, and the upstream transition section is tangent to the nozzle convergent section 1; the molded surface of the downstream transition section 3 is a secondary curve, the circular arc radius of the downstream transition section is 0.6 times of the throat radius, and the initial expansion half angle of the spray pipe is 28 degrees; the profile of the basic expansion section 4 is one of polynomial, conical and spline curves, the length of the basic expansion section is represented by an empirical formula, the initial expansion half angle is 28 degrees, and the final expansion half angle is 6 degrees;

2. a multi-stage bell-type extension section comprising: a flexible extension 5; the molded surface of the flexible extension section 5 is one of polynomial, conical and spline curves, and is unfolded along with the rise of the flying height, and the final expansion half-angle is 6 degrees under different working heights;

3. a variable constraint point portion comprising: a restraint positioning device 6; the constraint positioning device 6 is positioned in the flexible extension section 5, the position of the constraint positioning device in the x-axis direction is variable, a plurality of constraint points are formed after the flexible extension nozzle is flexibly unfolded, and the deformation scale of the molded surface of the flexible extension nozzle with the plurality of constraint points is reduced;

4. a support structure portion comprising: a support panel 7; the support slats 7 are located inside the flexible extensions 5 and their position in the x-axis direction is determined by the constraint positioning means 6, thereby providing hoop, radial and hoop-radial simultaneous constraints.

The invention has the beneficial effects that:

1. the invention utilizes the design of the flexible extension spray pipe to change the traditional fixed expansion ratio of the spray pipe into the variable expansion ratio which changes along with the working height, ensures that the spray pipe is always in a complete expansion state, and greatly reduces the thrust loss in the working process of the engine at present;

2. the existing graded extension spray pipe is designed to be improved to extend along with the height in real time, so that over-expansion hardly exists in the working process of an engine, the inner profile of a flexible material is more continuous, and the flow field distortion is reduced;

3. the conventional conical spray pipe fixed expansion section and flexible extension section are changed into a multi-bell-shaped design, so that the conical spray pipe is difficult to realize complete expansion, the overall length of the spray pipe can be greatly shortened through the multi-bell-shaped spray pipe, the weight of an engine is reduced, and the in-flight resistance can be effectively reduced;

4. the deformation scale of the flexible expansion molded surface of the spray pipe is effectively reduced through the design of the constraint points so as to reduce the thrust loss, and the design can eliminate the side effect of the flexible molded surface to the maximum extent and maximize the height compensation effect;

5. the flexible expansion and fixation of the spray pipe are carried out by adopting three modes of annular constraint, radial constraint and radial annular simultaneous constraint, so that the molded surface of the spray pipe can be effectively maintained, and the deformation is reduced;

6. the real-time height compensation of the engine is realized through the structure of the flexible extension spray pipe, the engine is ensured to be always in a complete expansion state in the working process, the thrust loss is greatly reduced, the performances of specific impulse and the like of the engine can be effectively improved, and the specific impulse and the thrust can be improved by more than 10% through the flexible extension spray pipe compared with the traditional spray pipe through numerical simulation verification;

7. compared with the existing conical spray pipe, the multi-bell spray pipe can effectively reduce the length, reduce the weight of the spray pipe, increase the effective load of an engine and reduce the manufacturing cost of the spray pipe;

8. compared with other extension spray pipes, the flexible extension spray pipe has the advantages of continuous molded surface, real-time height compensation, better sealing performance, simple structure, light weight, high reliability and the like, overcomes the problems that the existing height compensation spray pipe is generally complex in structure, heavy in weight and only capable of performing graded compensation, and has the advantages of continuous variable area ratio, simple structure, high mass ratio, high specific impulse and high performance;

9. the design through flexible extension has realized that the spray tube extends along with high real-time expansion, nevertheless because adopt flexible material spray tube to have certain deformation, so adopt fixed restraint to keep the spray tube profile, through numerical simulation verification, the hoop restraint and the radial restraint of fixed restraint point can make the spray tube profile warp very little, and is little to the influence of whole compensation effect, compares still very big advantage in present extension spray tube, has fine application prospect.

Drawings

FIG. 1 is a block diagram of a base section bell nozzle portion of a flexible extension nozzle of adaptive height;

FIG. 2 is a block diagram of the flexible extension spout of the present invention without the fixed restraint;

FIG. 3 is a block diagram of the flexible extension nozzle of the present invention with 4 fixed circumferential restraints;

FIG. 4 is a block diagram of a flexible extension nozzle of the present invention employing hoop restraint;

FIG. 5 is a block diagram of the flexible extension nozzle of the present invention employing radial restraint;

FIG. 6 is a block diagram of a flexible extension spout of the present invention utilizing both hoop and radial restraint.

The reference numbers in the figures are: the device comprises a nozzle convergent section 1, an upstream transition section 2, a downstream transition section 3, a basic expansion section 4, a flexible extension section 5, a constraint positioning device 6 and a support lath 7.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, the present invention is further described with reference to the accompanying drawings:

the technical scheme of the invention is realized as follows: the flexible extension spray pipe comprises a fixed section, a flexible extension section, a variable restriction point and a deployment device, and is designed into a multi-bell shape, and the extension section can be deployed according to the flying height. The inner profile of the spray pipe after being unfolded is in a multi-bell shape, the characteristic line of each extension section adopts a polynomial curve or a B-spline curve and the like, and the outlet of each section is in a full expansion state. The flexible extension nozzle can be expanded in multiple sections, and the expansion ratio of the nozzle can be increased from more than ten to hundreds. The positions of the constraint points are variable, a plurality of constraint points can be arranged after flexible expansion, and when the constraint points are more, the deformation scale of the spray pipe profile can be reduced. The support structure has multiple restraint modes including annular restraint, radial restraint and annular and radial simultaneous restraint.

The invention aims to provide a flexible extension nozzle structure capable of changing the area ratio along with the working height, aiming at the problem of low working efficiency of the existing single-stage in-orbit rocket and other rockets with wide working range.

The invention comprises a base section bell-shaped spray pipe, a multi-stage bell-shaped extension section, a variable constraint point and a support structure. The basic section spray pipe is a fixed spray pipe, the rest part of the basic section spray pipe is in a rolled state during launching, and after the flying height is raised, the extension section is unfolded by the supporting structure and fixed at the position of a constraint point, so that thrust loss caused by overlarge deformation scale of the spray pipe profile is avoided.

The inner profile of the spray pipe consists of an upstream transition section, a convergence section, a downstream transition section, a basic expansion section and a subsequent expansion section, wherein the inner profile of each expansion section is bell-shaped after being expanded, and the convergence section is 45 degrees.

The upstream transition section of the spray pipe consists of an arc with the radius 1.5 times of the radius of the throat part and is tangent to the convergent section; the profile of the downstream transition section is a quadratic curve, the radius of the circular arc of the transition section is 0.6 times of the radius of the throat part, and the initial expansion half angle of the spray pipe is 28 degrees.

The molded surface of the basic expansion section of the spray pipe is a polynomial, conical or spline curve, the length of the expansion section is an empirical formula, the initial expansion half angle is 28 degrees, and the final expansion half angle is 6 degrees.

The molded surface of the flexible extension section of the spray pipe is also a polynomial, conical or spline curve, the final expansion half angle is 6 degrees under different working heights, and the flexible extension section is gradually expanded along with the change of the working heights so as to ensure that the spray pipe is in a full expansion state under each working height.

The design of the constraint points of the spray pipe can be in various conditions, and according to the actual working condition of an engine and the weight of a supporting structure, the more constraint points are theoretically obtained, the smaller the deformation quantity of the flexible expansion section of the spray pipe is, the smaller the thrust loss is caused, and the better the compensation effect of the spray pipe is, but the weight of the supporting structure and the weight of the constraint points are increased, and the unrepensive condition can occur.

The following embodiment of the present invention is given with specific numerical values, the solid rocket engine room pressure in this embodiment is 7.2MPa, the base section working height is 6 km, and since the expansion ratio of the nozzle reaches 369.53 at a working height of 40km, a larger expansion ratio is not only technically difficult to realize, but also causes problems in the structural design of the engine, increases the weight of the engine, and the final design working height of the flexible extension nozzle is 40 km.

As shown in FIG. 1, the basic section nozzle of the present invention is composed of a convergent section, an upstream transition section, a downstream transition section and a basic expansion section, the expansion ratio of the sections is fixed, the nozzle is fully expanded only when the aircraft is at the working height of 6 kilometers, and the nozzle is in an under-expanded state when the aircraft is higher, so that the optimal performance of the engine can not be exerted.

FIG. 2 shows an unconstrained flexible extension nozzle configuration that can be extended in real time with altitude to maintain full expansion, with a 10.9% increase in specific impulse and a 9.7% increase in thrust compared to a base nozzle when the flight altitude is 40 km; when the working height is 60 kilometers, the specific impulse is improved by 18.87% and the thrust is improved by 17.74% compared with a basic spray pipe.

Fig. 3 shows a flexible extension nozzle structure with 4 constraint points, each of which is arranged according to a corresponding working height, and when the flexible nozzle is gradually unfolded, the constraint points can help to maintain a profile and reduce loss caused by profile deformation. Compared with the non-constrained nozzle, the thrust of the 4-constrained nozzle can be improved by 471.5N, and the specific impulse can be improved by 35.18 m/s; compared with a restricted nozzle, the thrust can be improved by 417.6N, and the specific impulse can be improved by 26.7 m/s; compared with two constrained nozzles, the thrust can be improved by 365.2N, the specific impulse can be improved by 11.9m/s, and the more constrained points are, the better the performance of the nozzle is. This is because the more the binding points, the shorter each flexible expansion section is, and the smaller the deformation dimension is, the smaller the influence on the thrust is.

FIG. 4 is a schematic view of the nozzle extension with hoop restraint. The hoop restraint is the application of an annular support structure on the nozzle expansion section, and the fixed restraint between each stage is added at the interface of each section of the shell pattern when the extension nozzle is deployed. The compensation effect of the spray pipe is improved by adding the constraint points, and the smaller the deformation scale of the spray pipe is, the better the compensation effect is. However, the increased restriction makes the nozzle structure more complicated and the weight of the nozzle increased. In addition, oblique shock waves generated at the outlet of the basic section are prevented from contacting with the wall surface after meeting, and air flow separation is generated due to reflection of the oblique shock waves after contact, so that the thrust performance of the spray pipe is reduced.

FIG. 5 is a simplified structural diagram of the nozzle extension with radial constraint. Radial restraint is the application of a support structure similar to an umbrella frame on the expansion section of the nozzle, similar to a fixed structure between each petal structure in a petal type extension nozzle. The radial constraint is applied to the side surface of the shell model, and at the moment, the shell generates deformation completely different from the annular constraint under the action of the internal and external pressure difference.

FIG. 6 is a schematic view of a nozzle extension with circumferential radial constraint. The annular fixing is added into the petal type structure, so that the original strip type extension structure is changed into a square shape, and the deformation of the flexible material is minimized. Applying radial restraint is effective in reducing casing deformation, and may be required to control nozzle deformation for materials with lower elastic modulus. However, to simplify the construction, the number of types of restrictions should be reduced, since the various restrictions complicate the deployment of the nozzle, increase the mass of the engine, with possible irreparable consequences.

In summary, the invention relates to a flexible extension nozzle structure capable of being unfolded in a self-adaptive height mode for a single-stage orbit rocket, the nozzle is integrally divided into a base section and a flexible extension section, the base section is designed by adopting a bell-shaped nozzle, the convergence section is composed of a straight line and an arc surface, a fixed convergence half angle is adopted, an upstream transition section is composed of an arc and is tangent to the convergence section, a downstream transition section is a quadratic curve, and the molded surface of the expansion section of the nozzle is a polynomial, a cone or a spline and the like. The flexible extension section is made of flexible materials, the molded surface can be designed into a polynomial curve, a cone or a spline curve and the like according to actual engineering requirements, and the whole spray pipe is double-bell-shaped or multi-bell-shaped. The flexible extension spray pipe has the advantages of continuously changing the area ratio, simple structure, high quality ratio and the like, and has greater advantages compared with the current height compensation spray pipe.