阅读说明：本技术 一种提高超声速柯恩达射流附着压比的环量控制单元 (Ring volume control unit for improving supersonic coanda jet flow adhesion pressure ratio ) 是由 张刘 黄勇 姜裕标 陈洪 高立华 李昌 汪军 何萌 于 2020-04-03 设计创作，主要内容包括：本发明公开了一种射流环量控制单元,所述射流环量控制单元设置于机翼的尾缘位置,射流环量控制单元包括第一高压气腔、第二高压气腔、第一喷嘴、第二喷嘴和柯恩达型面,第一喷嘴与所述第一高压气腔相连通,且第一喷嘴朝向机翼尾部设置,第二喷嘴与第二高压气腔相连通,且第二喷嘴朝向机翼尾部设置；第一喷嘴和第二喷嘴间设置有柯恩达型面,且所述第一喷嘴和/或第二喷嘴与柯恩达型面间设有台阶结构。通过所述台阶结构设置,使得在喷嘴射流出口处形成回流区,从而促进射流膨胀。因膨胀不足引起的激波与台阶形成的回流区的剪切层相互作用,减轻膨胀不足影响的效果,防止激波引起的分离,从而在较高的压力比下促进射流的附着。(The invention discloses a jet circulation control unit which is arranged at the tail edge of a wing and comprises a first high-pressure air cavity, a second high-pressure air cavity, a first nozzle, a second nozzle and a coanda profile, wherein the first nozzle is communicated with the first high-pressure air cavity and arranged towards the tail of the wing; a coanda profile is arranged between the first nozzle and the second nozzle, and a step structure is arranged between the first nozzle and/or the second nozzle and the coanda profile. By means of the step structure arrangement, a backflow zone is formed at the jet outlet of the nozzle, so that jet expansion is promoted. The shock wave caused by insufficient expansion interacts with the shear layer of the recirculation zone formed by the steps, the effect of insufficient expansion is reduced, separation caused by the shock wave is prevented, and attachment of the jet flow is promoted at a higher pressure ratio.)

1. A jet circulation control unit is characterized in that the jet circulation control unit is arranged at the tail edge of a wing,

the jet circulation control unit comprises a first high-pressure air cavity, a second high-pressure air cavity, a first nozzle, a second nozzle and a coanda profile,

the first nozzle is communicated with the first high-pressure air cavity, the first nozzle is arranged towards the tail of the wing, the second nozzle is communicated with the second high-pressure air cavity, and the second nozzle is arranged towards the tail of the wing;

a coanda profile is arranged between the first nozzle and the second nozzle, and a step structure is arranged between the first nozzle and/or the second nozzle and the coanda profile.

2. The unit of claim 1, wherein the step structure is a rearward step, and the gap formed by the connection between the rearward step and the coanda profile is oriented aft of the airfoil.

3. The jet circulation control unit of claim 2, wherein said rearward step includes an angle β with the tangent of the coanda profile, said angle being between 60 ° and 120 °.

4. The fluid circulation control unit of claim 1, wherein the step height t of the step structure is set based on a fluid pressure ratio of the air flow ejected from the first nozzle and/or the second nozzle.

5. A fluidic circuit volume control unit as claimed in claim 1, characterized in that the step height t of the step structure is set on the basis of the nozzle outflow height h of the first nozzle and/or the second nozzle and the standing chamber pressure ratio.

6. The jet circulation control unit of claim 1, wherein said coanda profile is arcuate in configuration and has a radius of curvature R.

7. The fluidic circuit volume control unit of claim 1, wherein the first nozzle and the second nozzle are convergent nozzles or convergent-divergent nozzles.

8. The jet circulation control unit of claim 1, wherein the first and second high pressure air chambers are in communication with a high pressure gas generating device.

9. An airfoil, characterized in that the airfoil is provided with a jet circulation control unit according to any one of claims 1 to 8.

10. An aircraft, characterized in that the aircraft comprises a wing structure, and the wing structure is provided with the jet circulation control unit as claimed in any one of claims 1 to 8, which is symmetrically arranged along the axis of the aircraft fuselage.

Technical Field

The invention belongs to the field of jet circulation control of active flow control of an airplane, and particularly relates to a circulation control unit capable of improving the supersonic coanda jet adhesion pressure ratio.

Background

The jet circulation control technology enables compressed air to be ejected along the tangential line of the trailing edge of the control unit through the jet control system, the jet deflects under the action of the coanda effect to form a virtual control surface, the pitch and roll control capacity equivalent to that of the traditional flight control surface is obtained, and the aircraft has the longitudinal and transverse control capacity. The jet velocity of the jet seam outlet is controlled through the total pressure of the adjusting ring volume control unit chamber, the blowing momentum coefficient is changed, the jet intensity is changed, the jet flow direction and the control effect of the virtual control surface are adjusted, and the requirements of different attitude adjustment of the airplane on the control moment are met.

The design idea of the jet flow flight control system is to use an airflow jet control system to realize the flight control without movable parts. Various movable control surfaces on the airplane and related control subsystem components thereof are eliminated, the airplane can be used for next-generation airplanes, the movable control surfaces on the airplane are reduced, and the airplane control system has important effects on reducing weight, using and maintaining cost and mechanism complexity and improving stealth, maneuverability and agility of the airplane. As a key technology which is likely to bring revolutionary changes to the design of future airplanes, the jet control technology without control surface has become a hot spot of research of various military and strong countries.

In order to improve the circulation control efficiency at high subsonic velocity, the jet velocity must be increased, and supersonic coanda jet is adopted. The traditional circulation control unit adopts a contraction nozzle, high-pressure ratio jet flow rapidly expands at the downstream of a nozzle outlet to generate a series of shock waves, and the shock waves interact with external free flow and a coanda surface boundary layer. At higher pressure ratios, the jet is highly under-expanded and the jet separates completely from the coanda surface in the form of shock boundary layer interactions, limiting the application of this technique.

To limit the desorption of the jet due to insufficient expansion, a converging-diverging nozzle is used to spread the gas stream to ambient pressure, expanding the working pressure range over which the coanda jet attaches. However, the shrinkage-expansion nozzle with special profile requirements is processed in a closed and narrow jet flow seam channel (the minimum size is about 0.2mm), the processing difficulty is high, the processing precision cannot be guaranteed, and the consistency of the jet flow nozzle in the extension direction is difficult to guarantee.

Disclosure of Invention

The invention aims to provide a design of a circulation control unit for promoting supersonic coanda jet adhesion, aiming at the problem of shock wave separation caused by insufficient expansion of high-pressure ratio jet under the condition of high subsonic velocity free incoming flow. A backward step is introduced between the jet flow outlet of the nozzle and the coanda profile to form a backflow area, so that the jet flow expansion is promoted, and the shock wave strength caused by insufficient jet flow expansion is reduced; the shock wave interacts with the free shear layer of the reflux area, so that the separation caused by the interaction of the shock wave and the boundary layer of the coanda surface is prevented, and the attachment of the jet flow on the coanda profile under a high pressure ratio is promoted; the step also provides a low pressure region that diverts the jet to the wall surface, promoting adhesion.

The purpose of the invention is realized by the following technical scheme:

a jet circulation control unit is arranged at the tail edge of a wing and comprises a first high-pressure air cavity, a second high-pressure air cavity, a first nozzle, a second nozzle and a coanda profile, wherein the first nozzle is communicated with the first high-pressure air cavity and arranged towards the tail of the wing, the second nozzle is communicated with the second high-pressure air cavity and arranged towards the tail of the wing; a coanda profile is arranged between the first nozzle and the second nozzle, and a step structure is arranged between the first nozzle and/or the second nozzle and the coanda profile.

By means of the step structure arrangement, a backflow zone is formed at the jet outlet of the nozzle, so that jet expansion is promoted. That is, the shock wave caused by the insufficient expansion interacts with the shear layer of the recirculation zone formed by the step, thereby reducing the effect of the insufficient expansion, preventing the separation caused by the shock wave, and promoting the adhesion of the jet flow at a high pressure ratio.

According to a preferred embodiment, the step structure is a backward step, and the gap formed by the connection between the backward step and the coanda profile faces the tail direction of the wing.

According to a preferred embodiment the angle between the rearward step and the tangent of the coanda profile is β and the angle is between 60 ° and 120 °.

According to a preferred embodiment, the step height t of the step structure is set on the basis of the jet pressure ratio of the air flow emitted by the first nozzle and/or the second nozzle.

According to a preferred embodiment, the step height t of the step structure is set on the basis of the nozzle outflow height h of the first nozzle and/or the second nozzle and the standing chamber pressure ratio.

According to a preferred embodiment, the coanda profile is an arcuate structure and the radius of curvature of the coanda profile is R.

According to a preferred embodiment, the first and second nozzles are convergent nozzles or convergent-divergent nozzles.

According to a preferred embodiment, the first high pressure gas chamber and the second high pressure gas chamber are in communication with a high pressure gas generating apparatus.

An airfoil is provided with a jet circulation control unit with the structure.

The aircraft comprises a wing structure, wherein the wing structure is provided with jet circulation control units which are symmetrically arranged along the axis of an aircraft body and have the structure.

The main scheme and the further selection schemes can be freely combined to form a plurality of schemes which are all adopted and claimed by the invention; in the invention, the selection (each non-conflict selection) and other selections can be freely combined. The skilled person in the art can understand that there are many combinations, which are all the technical solutions to be protected by the present invention, according to the prior art and the common general knowledge after understanding the scheme of the present invention, and the technical solutions are not exhaustive herein.

The invention has the beneficial effects that: the invention discloses a jet circulation control unit, which promotes jet expansion and reduces shock wave intensity by introducing a backward step between a jet outlet of a nozzle and a coanda profile, and converts shock wave-boundary layer mutual interference into shock wave-free shear layer interaction, thereby preventing separation caused by the interaction between the shock wave and the boundary layer of the coanda profile and promoting the attachment of jet flow on the coanda profile under a higher pressure ratio.

Drawings

FIG. 1 is a schematic structural view of an airfoil of the present invention;

FIG. 2 is a schematic diagram of a configuration of a circulation control unit according to the present invention;

FIG. 3 is a schematic diagram of the parameters involved in the circulation control unit of the present invention;

FIG. 4 is a schematic flow diagram of a supersonic coanda jet of the present invention;

wherein 100-wing, 101-wing wall, 102-first high pressure air cavity, 103-second high pressure air cavity, 104-coanda profile, 105-first nozzle, 106-second nozzle, 107-backward step.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.

It should be noted that, in order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments.

Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations and positional relationships that are conventionally used in the products of the present invention, and are used merely for convenience in describing the present invention and for simplicity in description, but do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhang" and the like do not imply that the components are required to be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, it should be noted that, in the present invention, if the specific structures, connection relationships, position relationships, power source relationships, and the like are not written in particular, the structures, connection relationships, position relationships, power source relationships, and the like related to the present invention can be known by those skilled in the art without creative work on the basis of the prior art.