CN211692653U

CN211692653U - S-shaped air inlet channel

Info

Publication number: CN211692653U
Application number: CN202020044696.9U
Authority: CN
Inventors: 刘汝兵; 林瑞鑫; 林麒; 薛生辉
Original assignee: Xiamen University
Current assignee: Xiamen University
Priority date: 2020-01-09
Filing date: 2020-01-09
Publication date: 2020-10-16
Anticipated expiration: 2030-01-09

Abstract

The application discloses an S-shaped air inlet, which comprises an air inlet body and a plurality of plasma synthetic jet actuators; the air inlet channel body is bent to a first direction along the air inlet direction, and the bent part of the air inlet channel body forms a curve; the jet orifice of each plasma synthetic jet actuator is arranged on the inner wall of the channel of the air inlet facing to the first direction in the air inlet channel body, the inner wall of the channel of the upstream part facing to the first direction and the inner wall of the channel of the downstream part facing away from the first direction and facing to the gas passage in the air inlet channel. By adopting the technical scheme, the phenomenon of gas flow separation in the gas inlet channel can be effectively inhibited, and the flow quality of the outlet of the gas inlet channel is improved.

Description

S-shaped air inlet channel

Technical Field

The utility model relates to a gas flow control field, concretely relates to S type intake duct.

Background

Stealth is an important performance index of modern high-performance fighters, and the survival ability of the aircraft is greatly improved by improving the stealth performance. The turbine engine rotating assembly in the air inlet of the modern jet aircraft is easily captured by reconnaissance equipment, and is a link which needs to be considered in the stealth design of the aircraft. Due to the unique structure of the S-shaped air inlet, radar waves are subjected to a series of reflections between the large-curvature wall surfaces after entering the air inlet, the energy of the radar waves is weakened in different degrees in each reflection process, the scattering area of the radar is reduced, and therefore the stealth performance is improved.

However, the S-shaped inlet also makes the airflow more complicated. In the large-curvature bending section, the air flow is subjected to flow separation due to a strong adverse pressure gradient, and the total pressure recovery coefficient of the outlet section of the air inlet passage is reduced due to the flow separation, so that the effective thrust is reduced. The twin scroll structure also produces large pressure distortion at the outlet of the air inlet, which deteriorates the performance of the engine and may even cause the compressor of the engine to surge or stall.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the above-mentioned defect or the problem that exist among the background art, provide a S type intake duct, restrain the interior gas flow separation phenomenon of intake duct, improve the mobile quality of intake duct export.

In order to achieve the purpose, the following technical scheme is adopted:

an S-shaped air inlet comprises an air inlet body, wherein the air inlet body is bent to a first direction along an air inlet direction, and the bent part of the air inlet body forms a curve; the plasma synthetic jet actuator also comprises a plurality of plasma synthetic jet actuators; the jet orifice of each plasma synthetic jet actuator is arranged on the inner wall of the channel of the air inlet facing to the first direction in the air inlet channel body, the upstream part of the curve facing to the inner wall of the channel of the first direction and the downstream part of the curve back to the inner wall of the channel of the first direction and the jet orifice of the plasma synthetic jet actuator faces to the gas passage in the air inlet channel body.

Furthermore, each plasma synthetic jet exciter is connected with a high-voltage pulse power supply through a corresponding electronic switch.

Further, the device also comprises a plurality of pressure sensors and a controller; each pressure sensor is at least arranged near the position of the jet orifice of the plasma synthetic jet actuator on the inner wall of the channel and sends a pressure value signal of the corresponding position; the controller is electrically connected with each pressure sensor and each electronic switch and is used for receiving pressure value signals sent by the pressure sensors and controlling the electronic switches corresponding to the plasma synthetic jet actuators at the corresponding positions to be switched on when the pressure values at the corresponding positions are smaller than a manually set threshold value.

Compared with the prior art, the scheme has the following beneficial effects:

compared with an S-shaped air inlet channel in the prior art, the S-shaped air inlet channel disclosed by the application can greatly inhibit the flow separation in the air inlet channel by arranging the plasma synthetic jet exciter in the air inlet channel body and injecting jet, thereby improving the flow quality of air at the air outlet of the air inlet channel and improving the overall performance of an engine. Meanwhile, the working state of the exciter can be controlled according to the pressure state of the position of the pressure sensor arranged on the air inlet, so that the condition of insufficient pressure in the area of the air inlet caused by some flight actions is improved.

Drawings

In order to more clearly illustrate the technical solution of the embodiments, the drawings needed to be used are briefly described as follows:

FIG. 1 is a perspective view of an S-shaped air intake duct in an embodiment;

FIG. 2 is a longitudinal sectional view of an S-shaped air inlet in the embodiment;

FIG. 3 is a schematic structural diagram of a plasma synthetic jet actuator according to an embodiment;

FIG. 4 is a schematic diagram illustrating an example of an S-shaped inlet circuit;

description of the main reference numerals:

the air inlet channel comprises an air inlet channel body 1, an air inlet 11, an upstream part 12 of a bend, a bend 13, a downstream part 14 of the bend and an air outlet 15; the plasma synthetic jet actuator comprises a plasma synthetic jet actuator 2, a first group of actuators 21, a second group of actuators 22, a third group of actuators 23, an excitation cavity 2a, a positive electrode 2b, a negative electrode 2c and a jet nozzle 2 d; a high-voltage pulse power supply 3; the electronic switch 4, the first electronic switch 41, the second electronic switch 42, the third electronic switch 43; pressure sensor 5, first group of pressure sensors 51, second group of pressure sensors 52, third group of pressure sensors 53; and a controller 6.

Detailed Description

In the claims and specification, unless otherwise specified the terms "first", "second" or "third", etc., are used to distinguish between different items and are not used to describe a particular order.

In the claims and specification, unless otherwise specified, the terms "central," "lateral," "longitudinal," "horizontal," "vertical," "top," "bottom," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "clockwise," "counterclockwise," and the like are used in the orientation and positional relationship indicated in the drawings and are used for ease of description only and do not imply that the referenced device or element must have a particular orientation or be constructed and operated in a particular orientation.

In the claims and the specification, unless otherwise defined, the terms "fixedly" or "fixedly connected" are to be understood in a broad sense as meaning any connection which is not in a relative rotational or translational relationship, i.e. including non-detachably fixed connection, integrally connected and fixedly connected by other means or elements.

In the claims and specification, unless otherwise defined, the terms "comprising", "having" and variations thereof mean "including but not limited to".

In the claims and specification, unless otherwise specified, the term "upstream portion of a curve" refers to the portion of the curve that is closer to the inlet of the intake manifold body, and "downstream portion of the curve" refers to the portion that is closer to the outlet of the intake manifold body.

The technical solution in the embodiments will be clearly and completely described below with reference to the accompanying drawings.

Referring to fig. 1 to 2, fig. 1 to 2 show an S-shaped air intake duct in an embodiment. As shown in the figure, the S-shaped air inlet in this embodiment includes an air inlet body 1, a plurality of plasma synthetic jet actuators 2, a high-voltage pulse power supply 3, an electronic switch 4, a pressure sensor 5, and a controller 6.

Wherein, the air inlet channel body 1 is provided with an air inlet 11 and an air outlet 15 as shown in fig. 1 and fig. 2. The inlet body 1 is curved in the inlet direction in a first direction a (shown in fig. 2), the curved portion of which forms a curve 13, which curve 13 can in turn be divided into an upstream portion 12 of the curve closer to the inlet 11 and a downstream portion 14 of the curve closer to the outlet.

Each plasma synthetic jet exciter 2 is provided with an excitation cavity 2a as shown in fig. 3, a positive electrode 2b and a negative electrode 2c extend into the excitation cavity 2a, and a jet nozzle 2d is communicated with the excitation cavity 2 a. The positive electrode 2b and the negative electrode 2c are connected with a high-voltage pulse power supply 3 through an electronic switch 4, after the electronic switch 4 is switched on, the positive electrode 2b and the negative electrode 2c generate sparks along with pulses, and continuously heat the gas in the excitation cavity 2a, so that the gas expands and is ejected from an opening of the jet nozzle 2d, namely a jet orifice. The plurality of plasma synthetic jet actuators 2 may be divided into three groups, namely a first group of actuators 21, a second group of actuators 22 and a third group of actuators 23. The jet orifices of the first group of actuators 21 are arranged on the inner wall of the channel facing the first direction a at the air inlet 11 in the air intake duct body 1, and in this embodiment, as shown in fig. 2, the inner wall of the channel located below is the inner wall of the channel facing the first direction a. The jet orifices of the second group of actuators 22 are arranged on the channel inner wall of the upstream portion 12 of the bend facing the first direction a, and likewise, in the present embodiment, the channel inner wall located below is the channel inner wall facing the first direction a. The jet ports of the third group of actuators 23 are arranged on the inner wall of the channel facing away from the first direction a in the downstream portion 14 of the curve, and in the present embodiment, as shown in fig. 2, the inner wall of the channel located above is the inner wall of the channel facing away from the first direction a. The plasma synthetic jet actuator 2 is arranged at the above-mentioned positions because these positions are the separation points of the gas flow separation of the S-shaped gas channel not loaded with the plasma synthetic jet actuator 2, wherein the jet orifices of the first set of actuators 21 are located at the flow separation points due to inlet distortion. The jet ports of the second set of actuators 22 are located at the point of flow separation caused by the upstream curve. The jet ports of the third group of actuators 23 are located at the point of flow separation caused by the downstream bend. The jet orifices of all the plasma synthetic jet actuators 2 face the gas passage in the gas inlet body 1. In this embodiment, the excitation cavities 2a of all the plasma synthetic jet actuators 2 are all disposed on the outer wall of the inlet channel body 1, and the jet nozzles thereof penetrate through the through holes on the inlet channel body 1 and open on the inner wall of the channel of the inlet channel body 1.

Three electronic switches 4 are correspondingly arranged on the three groups of plasma synthetic jet actuators 2, as shown in fig. 4, a first electronic switch 41 is correspondingly arranged on the first group of actuators 21, a second electronic switch 42 is correspondingly arranged on the second group of actuators, and a third electronic switch 43 is correspondingly arranged on the third group of actuators. The three groups of plasma synthetic jet actuators 2 are connected in series with the corresponding electronic switches 4 and then connected in parallel with each other to the high-voltage pulse power supply 3.

The pressure sensors 5 are at least arranged near the position of the jet orifice of the plasma synthetic jet actuator 2 on the inner wall of the channel, and send pressure value signals of corresponding positions to the controller. In the present embodiment, the pressure sensors are divided into three groups, i.e., a first group of pressure sensors 51, a second group of pressure sensors 52, and a third group of pressure sensors 53. As shown in fig. 2, the first group of pressure sensors 51 is located near the jet ports of the first group of actuators 21; a second set of pressure sensors 52 is located near the jet ports of the second set of actuators 22; the third group pressure sensor 53 is located near the jet port of the third group actuator 23. Of course, the pressure sensors 5 may be arranged in other ways, for example, they may be arranged above and below the inner wall of the air inlet in the air flow direction to form strip-shaped pressure sensors 5 to monitor the air pressure at various positions in the air inlet. In this case, the pressure sensors 5 are also divided into three groups, corresponding to the three groups of the plasma synthetic jet actuators 2. For example, all of the pressure sensors 5 located at the inlet 11 are taken as a first group of pressure sensors 51, all of the pressure sensors 5 located at the upstream portion 12 of the curve are taken as a second group of pressure sensors 52, and all of the pressure sensors 5 located at the downstream portion 14 and the outlet 15 of the curve are taken as a third group of pressure sensors 53.

The controller 6 is electrically connected with each pressure sensor 5 and each electronic switch 4 to receive the pressure value signal sent by the pressure sensor 5 and control the electronic switch 4 corresponding to the plasma synthetic jet exciter 2 at the corresponding position to be switched on when the pressure value at the corresponding position is smaller than the artificially set threshold value. In this embodiment, a separate threshold value may be set for the pressure value at each position, and the electronic switch 4 corresponding to the plasma synthetic jet actuator 2 at the corresponding position is controlled to be turned on when the pressure value at the corresponding position is lower than the threshold value. For example, when the aircraft performs some flight actions to cause the pressure at the position of the upstream portion 12 of the curve to be insufficient, if the pressure value in the pressure value signal sent by the second group pressure sensor 52 is lower than the pressure value threshold set for the upstream portion 12 of the curve, the second electronic switch 42 connected in series corresponding to the second group actuator 22 is controlled to be turned on, so that the high-voltage pulse power supply 3 supplies power to the second group actuator 22, and the actuator injects jet flow into the intake duct body 1, thereby suppressing the gas flow separation phenomenon at the upstream portion 12 of the curve, improving the flow quality at the intake duct outlet, and improving the overall performance of the engine.

The description of the above specification and examples is intended to illustrate the scope of the invention, but should not be construed as limiting the scope of the invention.

Claims

1. An S-shaped air inlet comprises an air inlet body, wherein the air inlet body is bent to a first direction along an air inlet direction, and the bent part of the air inlet body forms a curve;

it is characterized by also comprising a plurality of plasma synthetic jet exciters;

the jet orifice of each plasma synthetic jet actuator is arranged on the inner wall of the channel of the air inlet facing to the first direction in the air inlet channel body, the upstream part of the curve facing to the inner wall of the channel of the first direction and the downstream part of the curve back to the inner wall of the channel of the first direction and the jet orifice of the plasma synthetic jet actuator all face to the gas passage in the air inlet channel body.

2. An S-shaped air inlet channel as claimed in claim 1, wherein each plasma synthetic jet exciter is connected to a high-voltage pulse power supply through a corresponding electronic switch.

3. An S-shaped air intake duct according to claim 2, further comprising a plurality of pressure sensors and a controller;

each pressure sensor is at least arranged near the position of the jet orifice of the plasma synthetic jet actuator on the inner wall of the channel and sends a pressure value signal of the corresponding position;

the controller is electrically connected with each pressure sensor and each electronic switch and is used for receiving pressure value signals sent by the pressure sensors and controlling the electronic switches corresponding to the plasma synthetic jet actuators at the corresponding positions to be switched on when the pressure values at the corresponding positions are smaller than a manually set threshold value.