CN105402048A - Low infrared signature lobe injection mixing device used for two-dimensional nozzle outlet - Google Patents

Abstract

The invention provides a low-infrared characteristic lobe ejection mixing device for the outlet of a binary nozzle, which includes a rectangular transition section, a wave section, a wave transition section and a separate cold and hot flow channel section. For the traditional two The high-temperature components inside the exhaust system (central cone, support plate, mixer) that cannot be effectively shielded by the nozzle profile can be effectively shielded by the special wave lobe profile of the device and the separate inner partition of the cold and hot flow channels. Reduce the detectable infrared radiation of these high-temperature components, and at the same time, the separate cold and hot flow channel sections separate the high-temperature gas flow from the ejected cold air flow, effectively reducing the resistance of the ejected cold air flow, It ensures that the amount of injected cold air flow is very considerable, and the cold and hot air are mixed at the outlet of the device, which greatly reduces the temperature of the jet flow, thereby reducing the infrared radiation of the jet flow.

Description

A Low Infrared Characteristic Lobe Ejection and Mixing Device for Binary Nozzle Outlet

technical field

The patent of the present invention relates to the technical field of suppression of infrared radiation characteristics of aircraft, specifically, it mainly relates to a low-infrared characteristic lobe ejection mixing device for binary nozzle outlets.

Background technique

Under the threat of the current complex electromagnetic search and detection environment and advanced ground-to-air and air-to-air weapons and equipment, the battlefield survival environment of aircraft is deteriorating day by day. How to improve the survivability of aircraft on the battlefield and implement effective attacks against the enemy has become one of the key technologies that modern warfare urgently needs to develop. According to statistics, in several air battles since the 1980s, aircraft shot down by infrared guided missiles accounted for 70-80% of the total number of aircraft shot down in the war. Mainly the threat of third-generation infrared air-to-air missiles. And with the rapid development of the fourth-generation infrared air-to-air missile, its threat is also increasing. Faced with the increasingly serious threat of infrared guided missiles and infrared detection systems, in order to seek countermeasures to improve the combat effectiveness and battlefield survivability of aircraft, countries around the world have launched research on aircraft infrared stealth technology.

Infrared stealth technology is a comprehensive technology against infrared detection methods. By adopting corresponding technical methods, the infrared heat radiation of weapons and equipment can be reduced, and the probability of being discovered by the opponent's infrared detectors can be reduced. The detectors of infrared guided missiles or infrared detection systems currently in service use the 3-5 μm band as the main working band, and the exhaust system is the main infrared radiation source of the aircraft in the 3-5 μm band, including the high-temperature solid wall inside the nozzle The infrared radiation of the infrared radiation and the infrared radiation of gas, it contributes more than 90% to the infrared radiation of the aircraft in this band. Therefore, the infrared radiation of the exhaust system should be the primary object of aircraft infrared radiation suppression, and it is one of the main problems that must be solved to realize the infrared stealth of the aircraft, which has a significant impact on the aircraft's combat performance and battlefield survivability.

The nozzle is the main component of the aircraft exhaust system. Its main function is to accelerate the expansion and discharge of the high-temperature and high-pressure gas after the turbine, thereby generating the thrust of the engine. The traditional nozzle is usually axisymmetric, which has the advantages of simple structure and good thrust characteristics, but poor stealth performance. Since the high-temperature wall inside the nozzle is directly exposed to the rear view range, the tail-facing infrared characteristics of the aircraft become particularly obvious, and its tail jet has a long high-temperature core area, high temperature, and large radiation range, which is the first choice for advanced infrared guided weapons. The main tracking target. The stealth design of the nozzle of the engine is one of the main technical ways to realize the infrared stealth of the exhaust system. Compared with the traditional axisymmetric nozzle, the improved design of the nozzle structure includes many kinds, such as the use of binary nozzle or special-shaped exit nozzle. Compared with the axisymmetric nozzle, the binary nozzle increases the contact area of the tail jet flow and the outflow flow under the condition of equal area of the nozzle outlet, strengthens the mixing of the two, reduces the temperature of the tail jet flow, and at the same time, at a certain direction, the binary nozzle can effectively shield the high-temperature solid wall inside the nozzle, thereby suppressing the infrared radiation characteristics of the exhaust system. The second is to use the injection technology, using the high-energy gas of the main nozzle to suck low-energy cold air to the mixing section of the injection nozzle, and the last two streams are mixed in the mixing section to reduce the temperature and temperature of the solid wall surface in the nozzle. The temperature of the gas flow shortens the length of the high-temperature core area of the tail jet, and at the same time, the ejector sleeve within the range of the direction angle of part of the detection angle can shield the high-temperature solid wall in the nozzle. In addition, there are other stealth designs, such as the mixer adopts wave lobe type, install guide vanes or radiation convection heat exchange plates inside the nozzle, or use cold air to cool the high-temperature wall inside the nozzle, etc., the ultimate purpose is to strengthen the mixing of airflow The heat exchange of the mixed wall can reduce the temperature, thereby reducing the infrared radiation.

For the research on the binary injection nozzle, foreign Choi et al. (ChoiYH, SohWY. Computational analysis of the flow field of a two-dimensionalejectornozzle [R]. AIAA-90-190, 1990) studied the two control parameters of the binary injection nozzle (area ratio and injection The effect of changes in total pressure ratio) was studied. There are also researches on binary injection nozzles in China, Liu Fucheng (Liu Fucheng, Jihonghu, Lin Lanzhi, Huang Wei, Liu Changchun, Siren. Effects of binary injection nozzle geometric characteristic parameters on thrust and infrared[ J]. Aerodynamics Acta, 2011, 06:1244-1250) studied the influence of the geometric characteristic parameters (spacing ratio and area ratio) of the binary injection nozzle on the thrust and infrared characteristics through numerical simulation.

Judging from the existing literature, the main profile characteristics of the current traditional binary injection nozzles (such as long casing binary injection nozzles, short casing binary injection nozzles, etc.) are The outlet is covered with a binary cylinder with a slightly larger equivalent diameter. The binary injection nozzle obtained in this way has very limited enhancement of the shielding effect on the high-temperature parts inside the nozzle, that is, the infrared radiation suppression effect on the solid wall is very limited. ; Secondly, the high-temperature gas flow of the nozzle and the cold air flow ejected from the nozzle begin to mix at the cross-sectional position of the nozzle outlet. Relatively large, resulting in a very limited amount of cold flow air outside the injection nozzle, so the traditional injection nozzle has a relatively limited suppression effect on jet infrared radiation.

Contents of the invention

The invention aims to overcome the deficiencies of the prior art, and provides a low-infrared characteristic lobe ejection mixing device for binary nozzle outlets that can significantly reduce the infrared characteristics of the engine under the premise of ensuring high aerodynamic performance.

The low-infrared characteristic lobe ejection and mixing device for binary nozzle outlet provided by the present invention includes a rectangular transition section 1, a lobe section 2, a lobe transition section 3 and a separated cold and hot flow channel section 4 connected in sequence , a number of continuous lobe structures are arranged in the lobe section 2, and the lobe structures are smoothly connected to the split cold and hot flow channel section 4 through the lobe transition section 3, and each lobe structure passes through the lobe transition Segment 3 is correspondingly connected with partitions 14; the partitions 14 are vertically arranged along the axial direction of the device and run through the entire split cold and hot flow channel section 4, separating the hot and cold air flow to form alternately distributed ejection cold air flow channels 13 and high temperature gas flow channel 15.

Further, the lobe structure includes a pair of lobe units that are mirror-symmetrical to the transverse middle section of the device, and each lobe unit includes an outer expansion lobe 11, an inner expansion lobe 10, and a wave connecting the inner and outer expansion lobes. Lobe connecting curved surfaces 12, each lobe connecting curved surface 12 is arranged approximately in a vertical direction, and is smoothly connected to a partition 14 through the lobe transition section 3;

The inner and outer expansion lobes are determined by their positions in the device. The outer expansion lobes 11 are near the outside of the device, and the inner expansion lobes 10 are close to the lateral symmetry plane of the device; the lobes at both ends are outer expansion lobes. 11, the lobe section 2 includes n pairs of up-down symmetrical outer expansion lobes 11, and n-1 pairs of inner expansion lobes 10;

The symmetrical outer expansion lobe 11 corresponds to the formation of a high-temperature gas flow channel 15 at the split cold and hot flow channel section 4 , and the symmetrical inner expansion lobe 10 corresponds to the formation of a cold air flow channel 13 at the split cold and hot flow channel section 4 .

Furthermore, define the inlet equivalent diameter of the rectangular transition section 1 as D1, the area of the inlet section 5 as A1, the aspect ratio as AR, and the width as L5; define the area of the exit section 7 of the lobe section 2 as A2, and the area of the lobe transition section 3 The area of the outlet section 8 is A3, and the area of the outlet section 9 of the split cold and hot flow channel section 4 is A4;

Define the axial length of rectangular transition section 1 as L1, the axial length of lobe section 2 as L2, the axial length of lobe transition section 3 as L3, and the axial length of split cold and hot flow channel section 4 as L4;

Define the radius of the end of the outer expansion lobe 11 as R1, the radius of the end of the inner expansion lobe 10 as R2, the height of the vertically symmetrical lobe connection surface 12 at the exit section 7 of the lobe section 2 is L6, and the vertically symmetrical lobe transition The height at the outlet section 8 of section 3 is L7; the width of the cold air flow channel 13 is L9, and the width of the high temperature gas flow channel 15 is L8;

Define the inlet equivalent diameter D1, area A1, aspect ratio AR and width L5 of the rectangular transition section 1 to be equal to the equivalent diameter, area, aspect ratio and width of the outlet of the connected binary nozzle respectively, and the width of the device should be kept equal to the size of L5 Change.

As a preference, the area A2 of the outlet section 7 of the lobe section 2 is equal to the area A1 of the inlet section 5 of the rectangular transition section 1; the area A3 of the outlet section 8 of the lobe transition section 3 includes the cold flow cross-sectional area and the hot flow cross-sectional area , the total area is equal to 2 times the area A1 of the inlet section 5 of the rectangular transition section 1, the cross-sectional area of the cold air flow channel 13 and the high temperature gas flow channel 15 is equal, and is 0.5 times A3; the split cold and hot flow channel section 4 The area A4 of the outlet section 9 includes the cross-sectional area of the cold flow and the area of the hot flow, the total area is equal to twice the area A1 of the inlet section 5 of the rectangular transition section 1, and the outlet cross-sectional area of the cold air flow channel 13 and the high-temperature gas flow channel 15 are equal, both of which are 0.5 times A4.

As a preference, the value of the logarithm n of the inner expansion lobe 11 is not less than 1.5 times the aspect ratio AR, and not more than 3 times the aspect ratio AR, and n is an integer.

As a preference, the axial length L1 of the rectangular transition section 1 is not less than 0.1 times the inlet equivalent diameter D1 of the rectangular transition section 1, and is not greater than 0.25 times D1; the axial length L2 of the lobe section 2 is not less than 0.8 times D1, and not greater than 1.2 times D1; the axial length L3 of the lobe transition section 3 is not less than 0.12 times D1, and not greater than 0.2 times D1; the axial length L4 of the split cold and hot flow channel section 4 is not less than 0.36 times D1, and not greater than 0.6 D1.

As a preference, the radius of the end of the outer expansion lobe 11 is R1, and the value of R1 is 1/4n times the width L5 of the entrance of the rectangular transition section 1; the radius of the end of the inner expansion lobe 10 is R2, and its value is 1/ 4(n-1) times L5; the height L6 of the lobe connecting curved surface 12 at the outlet section 7 of the lobe section 2 is not less than 0.27 times the equivalent diameter D1 of the inlet of the rectangular transition section 1, and not more than 0.58 times D1; The value of the height L7 at the outlet section 8 of the flap transition section 3 is L6+πR1/2; the width L9 of the cold air flow channel 13 is equal to R2; the width L8 of the high temperature gas flow channel 15 is equal to R1.

Compared with the prior art, the present invention adopts the above technical scheme and has the following technical effects:

On the one hand, the traditional binary nozzle and binary injection nozzle profile cannot effectively shield the central cone, support plate, mixer, etc. of the high-temperature components inside the exhaust system. The special lobe profile and separate The partitions in the hot and cold flow channels can form an effective shield, thereby reducing the infrared radiation of these high-temperature components. Compared with the binary nozzle not connected with this device, the binary nozzle connected with this device is in the detection range dominated by solid wall radiation, and the infrared radiation at a detection angle of 15° on the horizontal detection surface has a maximum decrease of 57.9%. The decrease rate of infrared radiation at 30° detection angle on the straight detection surface reaches the maximum of 36.9%.

On the other hand, the split cold and hot flow channel section of the device of the present invention separates the high-temperature gas flow from the ejected cold air flow, effectively reducing the resistance of the ejected cold air flow, and ensuring the injection of cold air flow. The amount of flow is very considerable, accounting for about 21.8% of the high-temperature gas flow. The low-temperature air injected comes from the air in the cabin outside the engine, so there is no need to separate an additional air source from the engine, so there will be no direct loss The thrust of the engine, the ejected low-temperature air can not only provide a certain thrust, but also can be mixed with the high-temperature gas flow discharged from the exhaust system at the outlet section of the device, effectively reducing the temperature of the high-temperature gas, thereby reducing the jet flow Infrared radiation intensity. Compared with the binary nozzle not connected with the device, the detection range dominated by the jet radiation on the horizontal and vertical detection planes of the binary nozzle connected to the device behind, at the angle of 90° sideways pure jet radiation, infrared The reduction rate of radiation can reach more than 52%.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing:

Fig. 1 is the schematic diagram of the vertical symmetry plane 1/2 model of the low-infrared characteristic lobe ejection mixing device for binary nozzle outlet of the present invention;

Fig. 2 is the schematic diagram of the 1/2 model of the horizontal symmetry plane of the low-infrared characteristic lobe ejection mixing device used for the outlet of the binary nozzle of the present invention;

Fig. 3 is a schematic diagram of a lobe unit of the device of the present invention;

Fig. 4 is a schematic diagram of the cross-sectional area A2 of the device of the present invention at the position 7 of the outlet section of the lobe section;

Fig. 5 is a schematic diagram of the cross-sectional area A3 of the device of the present invention at the outlet cross-section position 8 of the lobe transition section;

Fig. 6 is the dimensionless integral radiation intensity comparison figure on the horizontal detection surface of the binary nozzle connected with the device of the present invention and the binary nozzle not connected with the device of the present invention;

Fig. 7 is the dimensionless integral radiation intensity contrast figure on the vertical detection surface of the binary nozzle connected with the device of the present invention and the binary nozzle not connected with the device of the present invention;

In the figure: 1. Rectangular transition section; 2. Lobe section; 3. Lobe transition section; 4. Split hot and cold flow channel section; 5. Rectangular transition section inlet section position; 6. Lobe section inlet section location; 7. Position of the exit cross-section of the lobe section; 8. Position of the exit cross-section of the lobe transition section; 9. Position of the exit cross-section of the split cold and hot flow channel; 10. Inner expansion lobe; 11. Outer expansion lobe; 12. Wave lobe Connecting curved surfaces; 13. Ejecting cold air flow channel; 14. Partition plate; 15. High temperature gas flow channel.

detailed description

The present invention provides a low-infrared characteristic lobe ejection and mixing device for binary nozzle outlets. In order to make the purpose of the present invention, technical solutions and effects clearer and clearer, the present invention will be further described in detail with reference to the accompanying drawings and examples . It should be understood that the specific implementations described here are only used to explain the present invention, not to limit the present invention.

Fig. 1 and Fig. 2 respectively provide a schematic diagram of a 1/2 model taken by a vertical symmetry plane and a schematic diagram of a 1/2 model taken by a horizontal symmetry plane of the lobe ejection mixing device. A low-infrared characteristic lobe ejection mixing device for the outlet of a binary nozzle, including a rectangular transition section 1, a lobe section 2, a lobe transition section 3 and a split cold and hot flow channel section 4 connected in sequence, in the There are several continuous lobe structures in the lobe section 2, and the lobe structures are smoothly connected to the split cold and hot flow channel section 4 through the lobe transition section 3, and each lobe structure is connected correspondingly through the lobe transition section 3 There are partitions 14; the partitions 14 are vertically arranged along the axial direction of the device and run through the entire split cold and hot flow passage section 4, separating the hot and cold air flow to form alternately distributed ejection cold air flow passages 13 and high-temperature gas flow channel 15 .

Further, the lobe structure includes a pair of lobe units that are mirror-symmetrical to the transverse middle section of the device. As shown in FIG. The lobe connecting curved surface 12 of the outer expansion lobe, each lobe connecting curved surface 12 is arranged roughly in the vertical direction, and is smoothly connected to a partition 14 through the lobe transition section 3;

The inner and outer expansion lobes are determined by their positions in the device. The outer expansion lobes 11 are near the outside of the device, and the inner expansion lobes 10 are close to the lateral symmetry plane of the device; the lobes at both ends are outer expansion lobes. 11, the lobe section 2 includes n pairs of up-down symmetrical outer expansion lobes 11, and n-1 pairs of inner expansion lobes 10;

The symmetrical outer expansion lobe 11 corresponds to the formation of a high-temperature gas flow channel 15 at the split cold and hot flow channel section 4 , and the symmetrical inner expansion lobe 10 corresponds to the formation of a cold air flow channel 13 at the split cold and hot flow channel section 4 .

Furthermore, define the equivalent diameter of the entrance of the rectangular transition section 1 as D1, the area of the entrance section 5 as A1, the aspect ratio as AR, and the width as L5; as shown in Figure 4, define the area of the exit section 7 of the lobe section 2 as A2 , as shown in Figure 5, the area of the outlet section 8 of the lobe transition section 3 is A3, and the area of the outlet section 9 of the split cold and hot flow channel section 4 is A4.

It can be seen from Fig. 4 and Fig. 5 that the area A3 of the outlet section 8 of the lobe transition section 3 includes the cold flow section area and the heat flow section area, and its total area is equal to twice the area A3 of the inlet section 5 of the rectangular transition section 1, so that the cold air can circulate The cross-sectional area of the road 13 and the high-temperature gas flow channel 15 is equal to A3 of 0.5 times; the area A4 of the outlet section 9 of the split cold and hot flow channel section 4 includes the cold flow cross-sectional area and the hot flow cross-sectional area, and the total area is equal to twice The area A1 of the inlet cross-section 5 of the rectangular transition section 1, the outlet cross-sectional area of the cold gas flow channel 13 and the high-temperature gas flow channel 15 are equal, which are 0.5 times A4.

Define the axial length of rectangular transition section 1 as L1, the axial length of lobe section 2 as L2, the axial length of lobe transition section 3 as L3, and the axial length of split cold and hot flow channel section 4 as L4;

Define the radius of the end of the outer expansion lobe 11 as R1, the radius of the end of the inner expansion lobe 10 as R2, the height of the vertically symmetrical lobe connection surface 12 at the exit section 7 of the lobe section 2 is L6, and the vertically symmetrical lobe transition The height at the outlet section 8 of section 3 is L7; the width of the cold air flow channel 13 is L9, and the width of the high temperature gas flow channel 15 is L8;

Define the inlet equivalent diameter D1, area A1, aspect ratio AR and width L5 of the rectangular transition section 1 to be equal to the equivalent diameter, area, aspect ratio and width of the outlet of the connected binary nozzle respectively, and the width of the device should be kept equal to the size of L5 Change.

Taking the binary nozzle outlet equivalent diameter as 0.576m, aspect ratio as 4, width as 1.44m, and area as ^0.5184m2 as the basic parameters, a few specific examples are given to better illustrate the composition of the device:

Example 1

Set the logarithm n of the outer expansion lobe to 6, then the logarithm of the inner expansion lobe is 5; the logarithm n of the outer expansion lobe is 1.5 times the aspect ratio, then the aspect ratio AR is 4, and the width L5 Take 1.44m; then the inlet equivalent diameter of the rectangular transition section 1 is taken as 0.576, and the area A1 of the inlet section 5 is 0.5184m ² .

The area A2 of the outlet section 7 of the lobe section 2 is equal to the inlet area of the rectangular transition section, which is 0.5184m ² , and the area A3 of the outlet section 8 of the lobe section 3 is twice the entrance area of the rectangular transition section, that is, 1.0368m ² . The area A4 of the outlet section 9 of the cold and hot flow passage section 4 is equal to it.

In terms of length, the axial length L1 of the rectangular transition section 1 is 0.1 times the equivalent diameter of the inlet of the rectangular transition section 1, which is 0.0576m. On this basis, the axial length L2 of the lobe section 2 is taken as 0.8 times the rectangular transition section 1 The inlet equivalent diameter is 0.4608m, the axial length L3 of the lobe transition section 3 is taken as 0.0691m, the axial length L4 of the split cold and hot flow channel section 4 is taken as 0.2074m, and the radius R1 at the end of the outer expansion lobe 11 is taken as 0.06m, The radius of the end of the inner expansion lobe 10 is R2, which is taken as 0.072m; the height L6 of the lobe connection curved surface 12 at the outlet section 7 of the lobe section 2 is taken as 0.1555m, and the height L7 at the outlet section 8 of the lobe transition section 3 is taken as 0.2498m , the width L9 of the cold gas flow channel 13 is taken as 0.072m, and the width L8 of the high temperature gas flow channel 15 is taken as 0.06m.

Example 2

Set the logarithm n of the outer expansion lobe to 12 pairs, then the logarithm of the inner expansion lobe is 11; the inlet equivalent diameter of the rectangular transition section 1 is 0.576, the aspect ratio AR is 4, and the width L5 is 1.44m.

According to the above data, the area A1 of the inlet section 5 is 0.5184m ² , the area A2 of the outlet section 7 of the lobe section 2 is the same as 0.5184m ² , and the area A3 of the outlet section 8 of the lobe transition section 3 is 1.0368m ² , separated The area A4 of the exit section 9 of the cold and hot flow channel section 4 is taken as 1.0368m ² .

In terms of length, the axial length L1 of the rectangular transition section 1 is 0.144m, the axial length L2 of the lobe section 2 is 0.6912m, the axial length L3 of the lobe transition section 3 is 0.1152m, and the split cold and hot flow channel section 4 The axial length L4 is 0.3456m, the radius R1 at the end of the outer expansion lobe 11 is 0.03m, and the radius R2 at the end of the inner expansion lobe 10 is 0.0327m; The height L6 at the location is 0.3341m, the height L7 at the outlet section 8 of the lobe transition section 3 is 0.3812m, the width L9 of the cold air flow channel 13 is 0.0327m, and the width L8 of the high temperature gas flow channel 15 is 0.03m.

Example 3

Set the logarithm n of the outer expansion lobes to 9 pairs, then the logarithm of the inner expansion lobes is 8; the inlet equivalent diameter of the rectangular transition section 1 is 0.576, the area A1 of the inlet cross section 5 is 0.5184m ² , and the aspect ratio AR is 4. The width L5 is 1.44m.

The area A2 of the outlet section 7 of the lobe section 2 is taken as 0.5184m ² , the area A3 of the outlet section 8 of the lobe transition section 3 is taken as 1.0368m ² , and the area A4 of the outlet section 9 of the split cold and hot flow channel section 4 is taken as 1.0368m ² .

The axial length L1 of the rectangular transition section 1 is taken as 0.103m, the axial length L2 of the lobe section 2 is taken as 0.5042m, the axial length L3 of the lobe transition section 3 is taken as 0.0808m, and the axial length L4 of the split cold and hot flow channel section 4 is taken as 0.2882m, the radius R1 at the end of the outer expansion lobe 11 is 0.04m, the radius at the end of the inner expansion lobe 10 is R2 and 0.045m; the height L6 of the lobe connecting curved surface 12 at the exit section 7 of the lobe segment 2 0.2454m, the height L7 at the outlet section 8 of the lobe transition section 3 is taken as 0.3082m, the width L9 of the cold gas flow channel 13 is taken as 0.045m, and the width L8 of the high temperature gas flow channel 15 is taken as 0.04m.

The above three low-infrared characteristic lobe ejection and mixing devices for binary nozzle outlets are all based on the following principles to achieve the design goal: the nozzle is an injection device for high-temperature and high-speed gas flow, and there is a low-pressure area behind it. The static pressure is less than the static pressure of the external environment. Therefore, the device can be used to introduce low-temperature air in the environment by utilizing the pressure difference between the external environment pressure and the low-pressure area. The low-infrared characteristic lobe ejection mixing device used in the outlet of the binary nozzle of the present invention forms a cold air guide channel between the adjacent outer expansion lobes of the lobe section, so that the low-temperature air in the engine room can enter the induction smoothly. The jet-cooled air flow channel; while the high-temperature gas flow discharged from the binary nozzle passes through the rectangular transition section, the lobe section, the lobe transition section and the high-temperature gas flow channel in turn, and is combined with the low-temperature air flowing out of the cold air flow channel in the device. Blending at the outlet cross-section position, thereby reducing the temperature of the high-temperature gas flow, and achieving the effect of infrared suppression of the jet flow. In addition, the special lobed surface of this device and the inner partition of the separated cold and hot flow channels can effectively shield the high-temperature components (central cone, support plate, mixer) inside the exhaust system, thereby reducing the infrared radiation of these high-temperature components, To achieve the effect of solid wall infrared suppression.

According to the numerical simulation result, shown in Fig. 6 is the dimensionless integral radiation intensity comparison figure on the horizontal detection surface of the binary nozzle connected with the device of the present invention and the binary nozzle not connected with the device of the present invention, and Fig. 7 is shown as The dimensionless integrated radiation intensity comparison diagram of the binary nozzle connected with the device of the present invention and the binary nozzle not connected with the device of the present invention on the vertical detection surface, as can be seen from the figure, compared with the binary nozzle not connected with the device tube, followed by the binary nozzle of the device, in the detection range dominated by solid wall radiation, the infrared radiation with a detection angle of 15° on the horizontal detection surface can decrease by a maximum of 57.9%, and the infrared radiation with a detection angle of 30° on the vertical detection surface In the detection range dominated by jet radiation on the horizontal and vertical detection surfaces, and at the angle of pure jet radiation of 90° laterally, the decrease of infrared radiation can reach more than 52%.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. the low infrared signature lobe injection mixing device for two-dimensional nozzle outlet, comprise the rectangular transition section (1), lobe section (2), lobe changeover portion (3) and the split hot and cold stream channel section (4) that connect successively, it is characterized in that: in described lobe section (2), be provided with some continuous print lobe structures, described lobe structure is by lobe changeover portion (3) smooth connection to split hot and cold stream channel section (4), and each lobe structure is connected with dividing plate (14) by lobe changeover portion (3) correspondence; Described dividing plate (14) vertically arranges along device axial direction and runs through whole split hot and cold stream channel section (4), is separated by hot and cold air, forms alternatively distributed injection cold airflow passage (13) and high-temperature fuel gas circulation road (15).

2. a kind of low infrared signature lobe injection mixing device for two-dimensional nozzle outlet according to claim 1, it is characterized in that: described lobe structure comprises a pair lobe unit with device lateral intermediate cross-section Mirror Symmetry, each lobe unit comprises outer expansion lobe (11), intramedullary expansion lobe (10) and connects lobe connection curved surface (12) of inside and outside expansion lobe, each lobe connects curved surface (12) and shows greatly vertical direction setting, and by lobe changeover portion (3) smooth connection dividing plate (14);

Described inside and outside expansion lobe is with its determining positions in device, and outside approaching device is outer expansion lobe (11), approaching device lateral symmetry face be intramedullary expansion lobe (10); The lobe at two ends is outer expansion lobe (11), then lobe section (2) comprises n to laterally zygomorphic outer expansion lobe (11), and comprises n-1 to interior expansion lobe (10);

Symmetrical outer expansion lobe (11) is corresponding forms high-temperature fuel gas circulation road (15) at split hot and cold stream channel section (4) place, and symmetrical intramedullary expansion lobe (10) is corresponding forms cold airflow passage (13) at split hot and cold stream channel section (4) place.

3. a kind of low infrared signature lobe injection mixing device for two-dimensional nozzle outlet according to claim 1, it is characterized in that: the import equivalent diameter of definition rectangular transition section (1) is D1, import cross section (5) area is A1, and Aspect Ratio is AR, and width is L5; Definition lobe section (2) outlet (7) area is A2, and lobe changeover portion (3) outlet (8) area is A3, and split hot and cold stream channel section (4) outlet (9) area is A4;

Definition rectangular transition section (1) axial length is L1, and lobe section (2) axial length is L2, and lobe changeover portion (3) axial length is L3, and split hot and cold stream channel section (4) axial length is L4;

The outer radius expanding lobe (11) end of definition is R1, the radius of intramedullary expansion lobe (10) end is R2, it is L6 at the height of lobe section (2) outlet (7) that laterally zygomorphic lobe connects curved surface (12), and the height at laterally zygomorphic lobe changeover portion (3) outlet (8) place is L7; The width of cold airflow passage (13) is L9, and the width of high-temperature fuel gas circulation road (15) is L8;

The import equivalent diameter D1 of definition rectangular transition section (1), area A 1, Aspect Ratio AR and width L5 are equal with the equivalent diameter that connected two-dimensional nozzle exports, area, Aspect Ratio and width respectively, and this device width keeps L5 size constant.

4. a kind of low infrared signature lobe injection mixing device for two-dimensional nozzle outlet according to claim 3, is characterized in that: described lobe section (2) outlet (7) area is import cross section (5) area A 1 that A2 equals rectangular transition section (1); Described lobe changeover portion (3) outlet (8) area A 3 comprises cold flow section area and hot-fluid section area, the gross area equals import cross section (5) area A 3 of the rectangular transition section (1) of 2 times, cold airflow passage (13) is equal with the section area of high-temperature fuel gas circulation road (15), is the A3 of 0.5 times; Described split hot and cold stream channel section 4 outlet 9 area A 4 comprises cold flow section area and hot-fluid section area, the gross area equals import cross section 5 area A 1 of the rectangular transition section 1 of 2 times, cold airflow passage (13) is equal with high-temperature fuel gas circulation road (15) exit area, is the A4 of 0.5 times.

5. a kind of low infrared signature lobe injection mixing device for two-dimensional nozzle outlet according to claim 2, it is characterized in that: the value of the logarithm n of described intramedullary expansion lobe (11) is not less than Aspect Ratio AR of 1.5 times, and be not more than Aspect Ratio AR of 3 times, n round numbers.

6. a kind of low infrared signature lobe injection mixing device for two-dimensional nozzle outlet according to claim 3, it is characterized in that: described rectangular transition section (1) axial length L 1 is not less than rectangular transition section (1) the import equivalent diameter D1 of 0.1 times, and is not more than the D1 of 0.25 times; Lobe section (2) axial length L 2 is not less than the D1 of 0.8 times, and is not more than the D1 of 1.2 times; Lobe changeover portion (3) axial length L 3 is not less than the D1 of 0.12 times, and is not more than the D1 of 0.2 times; Split hot and cold stream channel section (4) axial length L 4 is not less than the D1 of 0.36 times, and is not more than the D1 of 0.6.

7. a kind of low infrared signature lobe injection mixing device for two-dimensional nozzle outlet according to claim 3, is characterized in that: the radius of described outer expansion lobe (11) end is that the value of R1 gets 1/4n rectangular transition section (1) entrance width L5 doubly; The radius of intramedullary expansion lobe (10) end is R2, and its value is taken as 1/4 (n-1) L5 doubly; Lobe connects curved surface (12) is not less than 0.27 times rectangular transition section (1) import equivalent diameter D1 at the height L6 at lobe section (2) outlet (7) place, and is not more than the D1 of 0.58 times; The value of the height L7 at lobe changeover portion (3) outlet (8) place is L6+ π R1/2; The width L9 value of cold airflow passage (13) is equal with R2; The value of the width L8 of high-temperature fuel gas circulation road (15) is equal with R1.