A special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing

Abstract

The invention discloses a special-shaped central cone with the function of suppressing infrared radiation and strengthening mixing, including a central cone located in the inner channel of the engine, a mixing tube is provided at the tip of the central cone extending along the airflow direction, one end of the mixing tube is rotatably matched with the tip of the central cone, and a tail cone is provided at the other end, the mixing tube is spiral, so that the body-attached incoming flow of the central cone generates circumferential velocity and strengthens mixing, the windward surface area of ​​the tail cone is larger than the mixing tube, and the tail cone is used to generate reflux of the inner channel airflow, and reduce the engine wake length by strengthening mixing. The invention can effectively strengthen mixing to shorten the length of the nozzle wake, and strengthen heat dissipation, so that the temperature is reduced faster.

Description

Technical Field

[0001] The invention relates to the technical field of pile foundation detection, and in particular to a special-shaped central cone with the function of suppressing infrared radiation and strengthening mixing. Background Art

[0002] Nowadays, infrared characteristic technology is developing rapidly, and the requirements for infrared stealth of aircraft are increasing. The main sources of infrared radiation in the 3-5um band are high-temperature components of aircraft engines and tail jets. The tail jet of an ordinary tail nozzle has the disadvantages of too long wake and too high temperature due to poor heat dissipation. For components such as afterburners and turbines, it is difficult to adopt cooling measures due to their special thermal and aerodynamic environment. The center cone has a greater impact on the wake. Therefore, the present invention uses the special position of the center cone to improve its structure to solve the problem of too long tail jet wake and poor heat dissipation of the nozzle. Summary of the invention

[0003] The purpose of the present invention is to solve the problems mentioned in the background technology and to provide a special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing.

[0004] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0005] A special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing comprises a central cone located in an inner duct of an engine, wherein: a mixing tube is provided at the tip of the central cone extending along the airflow direction, one end of the mixing tube is rotatably matched with the tip of the central cone, and a tail cone is provided at the other end, the mixing tube is spiral-shaped, so that the incoming flow close to the central cone generates circumferential velocity enhanced mixing, the windward surface area of ​​the tail cone is larger than that of the mixing tube, and the tail cone is used to generate backflow of the inner duct airflow, thereby reducing the engine wake length by enhancing mixing.

[0006] In some of the embodiments, the mixing tube is connected to the cone tip of the central cone via a rotating bushing, and the connection between the cone tip of the central cone, the rotating bushing and the mixing tube is smoothly transitioned.

[0007] In some of the embodiments, a plurality of shrapnel mounting grooves are provided in the tail end cone, and the shrapnel mounting grooves are open on the outer peripheral surface of the tail end cone. A shrapnel is installed in each shrapnel mounting groove, and the shrapnel is connected to the shrapnel mounting groove through a spring. When the tail end cone rotates with the mixing tube, the shrapnel can move outward from the shrapnel mounting groove under the action of centrifugal force, thereby increasing the windward surface area of ​​the tail end cone.

[0008] In some of the embodiments, a fan-shaped impact groove is provided on the windward surface of the spring piece, and the groove wall on one side of the fan-shaped impact groove close to the outer end of the spring piece is inclined outward to form a wind guide surface. The wind guide surface causes the airflow impacting the fan-shaped impact groove to produce backflow while pushing the spring piece outward, thereby increasing the windward surface area of ​​the tail end cone.

[0009] In some of the embodiments, a cooling air nozzle is provided on the lateral surface of the shrapnel. When the shrapnel is completely located in the shrapnel mounting groove, the cooling air nozzle is completely blocked by the wall of the shrapnel mounting groove. When the shrapnel moves outward from the shrapnel mounting groove, the cooling air nozzle gradually breaks away from the blocking of the wall of the shrapnel mounting groove. A cold air channel is provided in the central cone and the mixing tube. The cold air channel can inject cold air into the cooling air nozzle. The cold air ejected from the cooling air nozzle can radially impact the inner airflow, thereby enhancing the mixing and reducing the temperature of the inner airflow.

[0010] In some of the embodiments, the mixing tube is a spiral structure with a gradually changing spiral diameter, wherein the spiral diameter of one end of the mixing tube close to the cone tip of the central cone is smaller than the spiral diameter of the other end of the mixing tube close to the rotating bushing.

[0011] In some of the embodiments, the spiral pitches of the spring pieces are equal and the number of turns is 3.

[0012] In some of the embodiments, the outer circumference of the spring sheet is arc-shaped, and its curvature is the same as the outer circumference of the tail end cone. When the spring sheet is completely located in the spring sheet installation groove, the outer circumference of the spring sheet is flush with the outer circumference of the tail end cone.

[0013] In some of the embodiments, a limit stopper is provided in the spring piece installation groove to prevent the spring piece from falling out.

[0014] In some of the embodiments, the depth of the fan-shaped impact groove is one tenth to one fifth of the thickness of the spring piece.

[0015] The present invention has the following advantages:

[0016] 1. The special-shaped central cone of the present invention generally adopts a rotatable spiral structure, which changes the flow direction of the body-cone flow through the spiral structure to promote the mixing of the wake flow. In addition, since there is a cold air channel in the spiral structure, the heat dissipation of the wake flow can be promoted through the large contact area of ​​the spiral structure, which can greatly improve the radiation of the wake flow.

[0017] 2. The end of the spiral structure of the present invention adopts a tail cone similar to the flame stabilizer of the combustion chamber, which can make the tail flow form a backflow downstream, thereby facilitating mixing and shortening the length of its tail, and enhancing heat dissipation, and the temperature drops faster.

[0018] 3. Since the spiral structure is added behind the special-shaped center cone, the inner duct area of ​​the tail nozzle is changed, causing its overall deviation from the design state. In order to make it have corresponding adaptability, a duct adjustment device, namely a spring structure, is added to the tail cone. There are several springs, which are arranged in a ring along the circumference of the tail cone. When there is no incoming flow, they are pulled into the spring installation groove by a spring with lower elasticity. When the incoming flow increases, the rotation is enhanced, and a small part of the spring is ejected by centrifugal force. At this time, the fan-shaped groove on the windward side of the spring will be impacted, thereby generating a radial outward force, causing the spring to extend further outward, thereby changing the inner duct area to achieve the adjustment effect.

[0019] 4. There are cooling air nozzles on the side of the shrapnel, and cooling gas will be ejected from the cold air channel. The flow rate of the cooling air nozzle is affected by the extension degree of the shrapnel. When the incoming flow speed is greater, the extension degree of the shrapnel is greater, the extension area of ​​the cooling air nozzle is larger, and the cooling gas flow rate is greater. The cooling airflow can be mixed with the downstream reflux to further reduce the temperature of the wake flow and reduce the radiation.

[0020] 5. The spiral diameter of one end of the mixing tube close to the cone tip of the center cone is smaller than the spiral diameter of the other end of the mixing tube close to the rotating bushing. Specifically, the spiral diameter of the end close to the cone tip of the center cone is 0, and the spiral diameter gradually increases from zero to the designed size. On the one hand, it can reduce the impact of sudden obstruction on the engine thrust, and on the other hand, it can more smoothly connect the body-fitting flow of the center cone to reduce loss and friction, and fewer turns can reduce the requirements for the structural strength of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention;

[0022] Figure 2 yes Figure 1 Stereoscopic image of

[0023] Figure 3 It is a schematic diagram of the structure of the shrapnel;

[0024] Figure 4 It is a three-dimensional picture of the shrapnel.

[0025] Names marked in the figure: center cone 1, mixing tube 2, tail cone 3, spring installation groove 31, limit baffle 32, spring 4, fan-shaped impact groove 41, cooling air nozzle 42, air guide surface 43, rotating bushing 5. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0027] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0028] like Figure 1-4 As shown, a special-shaped central cone with the function of suppressing infrared radiation and strengthening mixing of the present invention comprises a central cone 1 located in the inner duct of the engine, the cone tip of the central cone 1 is provided with a mixing tube 2 extending along the airflow direction, one end of the mixing tube 2 is rotatably matched with the cone tip of the central cone 1, and the other end is provided with a tail cone 3, the mixing tube 2 is spiral, the mixing tube 2 is connected to the cone tip of the central cone 1 through a rotating bushing 5, and the connection between the cone tip of the central cone 1, the rotating bushing 5 and the mixing tube 2 is smoothly transitioned. A plurality of spring clip installation grooves 31 are provided in the tail cone 3, the spring clip installation grooves 31 are opened on the outer peripheral surface of the tail cone 3, and a spring clip 4 is installed in each spring clip installation groove 31, and the spring clip 4 is connected to the spring clip installation groove 31 through a spring. A fan-shaped impact groove 41 is provided on the windward surface of the spring clip 4, and the groove wall of the fan-shaped impact groove 41 close to the outer end of the spring clip 4 is inclined outward to form a wind guide surface 43. A cooling air nozzle 42 is arranged on the windward side of the spring piece 4 , and a cold air channel is arranged in the central cone 1 and the mixing tube 2 , and the cold air channel can inject cold air into the cooling air nozzle 42 .

[0029] The functions of the main structures of the present invention are as follows:

[0030] Mixing tube 2: It is used to generate circumferential velocity and enhance mixing for the close-fitting flow of the center cone.

[0031] Tail cone 3: used to generate backflow of the inner duct airflow and reduce the engine wake length by enhancing mixing.

[0032] The spring installation groove 31 serves as a cooling air passage and a space for placing a low-elasticity spring.

[0033] Shrapnel 4: used to adjust the bypass ratio.

[0034] The fan-shaped impact groove 41 is located on the windward surface of the spring piece 4 and can utilize the impact force of the incoming flow to generate a radial outward force to make the spring piece 4 slide outward.

[0035] Cooling air nozzle 42: The ejected cold air can radially impact the inner channel airflow, strengthen the mixing and reduce the inner channel airflow temperature, thereby reducing the infrared radiation by reducing the wake temperature.

[0036] Rotating bushing 5: used to connect the center cone 1 and the mixing tube 2, and also to enable the two to rotate relative to each other, so that the incoming flow generates circumferential velocity to enhance mixing.

[0037] The following are some specific settings of each structure of this embodiment:

[0038] 1) The front end of the center cone has the size parameters of an ordinary center cone.

[0039] 2) The spiral diameter of the mixing tube 2 is gradually expanded in equal proportion, starting from 0 to the designed diameter.

[0040] 3) The pitch of the spiral structure of the mixing tube 2 is equal, and the number of turns is 3.

[0041] 4) The tail cone 3 is coaxial with the mixing tube 2 and the center cone 1, and is also coaxial with the inner channel of the engine.

[0042] 5) The space reserved in the spring piece installation groove 31 is sufficient to install the low elastic spring so as not to affect the complete retraction of the slider into the groove.

[0043] 6) The depth of the fan-shaped impact groove 41 is 1 / 10 to 1 / 5 of the thickness of the spring piece 4 .

[0044] 7) There are four springs 4, which are arranged on the tail cone 3 with equal arcs. Figure 3-4 Only one of the spring pieces 4 is shown, and the other three are not shown.

[0045] 8) The limit stopper 32 is a stopper fixedly installed at the opening of the spring installation slot 31. Figure 3-4 It is not clearly shown in the figure, but it should be pointed out that the limit stopper only needs to limit the spring sheet 4 so that it cannot completely escape from the spring sheet installation groove 31. Its structural form is diverse and it is a prior art means.

[0046] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A special-shaped central cone having the function of suppressing infrared radiation and enhancing mixing, comprising a central cone (1) located in an inner channel of an engine, characterized in that: The tip of the central cone (1) is provided with a mixing tube (2) extending along the airflow direction. One end of the mixing tube (2) is rotatably matched with the tip of the central cone (1), and the other end is provided with a tail cone (3). The mixing tube (2) is spirally shaped, so that the incoming flow close to the central cone (1) generates circumferential velocity and enhanced mixing. The windward surface area of ​​the tail cone (3) is larger than that of the mixing tube (2). The tail cone (3) is used to generate backflow of the inner duct airflow, thereby reducing the engine wake length by enhancing mixing.

2. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 1 is characterized in that: The mixing tube (2) is connected to the cone tip of the central cone (1) via a rotating bushing (5), and the connection between the cone tip of the central cone (1), the rotating bushing (5) and the mixing tube (2) is smoothly transitioned.

3. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 2 is characterized in that: A plurality of spring-clip installation grooves (31) are arranged in the tail end cone (3), and the spring-clip installation grooves (31) are open on the outer peripheral surface of the tail end cone (3). A spring (4) is installed in each of the spring-clip installation grooves (31), and the spring (4) is connected to the spring-clip installation groove (31) via a spring. When the tail end cone (3) rotates with the mixing tube (2), the spring (4) can move outward from the spring-clip installation groove (31) under the action of centrifugal force, thereby increasing the windward surface area of ​​the tail end cone (3).

4. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 3 is characterized in that: A fan-shaped impact groove (41) is arranged on the windward surface of the spring piece (4), and a groove wall on one side of the fan-shaped impact groove (41) close to the outer end of the spring piece (4) is inclined outward to form a wind guide surface (43). The wind guide surface (43) causes the airflow that impacts the fan-shaped impact groove (41) to generate a backflow, and can push the spring piece (4) outward, thereby increasing the windward surface area of ​​the tail end cone (3).

5. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 4 is characterized in that: The lateral wind surface of the spring piece (4) is provided with a cooling air nozzle (42). When the spring piece (4) is completely located in the spring piece mounting groove (31), the cooling air nozzle (42) is completely blocked by the groove wall of the spring piece mounting groove (31). When the spring piece (4) moves outward from the spring piece mounting groove (31), the cooling air nozzle (42) gradually escapes from the blocking of the groove wall of the spring piece mounting groove (31). A cold air channel is provided in the central cone (1) and the mixing tube (2). The cold air channel can inject cold air into the cooling air nozzle (42). The cold air ejected from the cooling air nozzle (42) can radially impact the inner channel airflow, thereby strengthening mixing and reducing the inner channel airflow temperature.

6. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 5 is characterized in that: The mixing tube (2) is a spiral structure with a gradually changing spiral diameter, wherein the spiral diameter at one end of the mixing tube (2) close to the cone tip of the central cone (1) is smaller than the spiral diameter at one end of the mixing tube (2) close to the tail cone (3).

7. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 6 is characterized in that: The spiral pitch of the spring piece (4) is equal, and the number of turns is 3.

8. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 7 is characterized in that: The outer circumference of the spring sheet (4) is arc-shaped, and its curvature is the same as that of the outer circumference of the tail end cone (3). When the spring sheet (4) is completely located in the spring sheet installation groove (31), the outer circumference of the spring sheet (4) is flush with the outer circumference of the tail end cone (3).

9. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 8 is characterized in that: A limit stopper (32) for preventing the spring sheet (4) from falling out is arranged in the spring sheet installation groove (31).

10. The special-shaped central cone with the function of suppressing infrared radiation and enhancing mixing according to claim 9, characterized in that: The depth of the fan-shaped impact groove (41) is one tenth to one fifth of the thickness of the spring piece (4).

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