JPH09133046A - Fluid mixing device for jet engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid mixing device for a jet engine by which mixing of a fan flow in a core flow can be further promoted, and, in this way, improvement of thrust, improvement of combustion efficiency of an after burner, reduction of noise by a jet flow and the like can be attained. SOLUTION: In a fluid mixing device 20 for a jet engine, a core flow 14 passing through a compressor, combustor and a turbine and a bypass flow 13 bypassing these members are provided. A small/large mixer 22, 24, provided in a cylindrical partition 17 partitioning the core flow and the bypass flow to mix the core flow in the bypass flow guided in a circumferential direction alternately to an outer/inner side, are provided. In the small/large mixer, diametric extension parts 22a, 24a gradually enlarging a diameter in the downstream and diametric contraction parts 22b, 24b gradually contracting the diameter are positioned alternately in a circumferential direction reversely to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid mixing apparatus (mixer) for mixing a fan flow and a core flow of a jet engine.
About.

[0002]

2. Description of the Related Art As shown in FIG. 4, an aircraft engine 1 (jet engine) having an afterburner includes a fan 2 that takes in air, a compressor 3 that compresses the taken-in air, and a combustor that burns fuel with the compressed air. 4, a turbine 5 that drives the fan 2 and the compressor 3 by the combustion gas of the combustor 4, an afterburner 6 that reburns to increase thrust, and the like.

The afterburner 6 has a triangular cross-section or the like and forms a circulation region X in the downstream for flame holding, and a fuel nozzle 8 for ejecting fuel.
It is composed of a spark plug 9 and the like, and is ejected from an exhaust nozzle 12 through a liner 11 inside the outer duct 10 to increase thrust.

The air taken in by the fan 2 is
Core flow 14 through compressor 3, combustor 4 and turbine 5
And bypass flow 13 (fan flow) that bypasses these
And are combined in a mixer (mixer) 15. In addition, 16 is a tail cone.

As shown in FIG. 5, the mixer 15 has a guide wall (partition wall) having a corrugated cross-sectional shape, and this corrugated shape is formed so as to become larger toward the downstream side, and the fan flow 13 ( The solid line) and the core flow 14 (broken line) join together to form a circulation region X (see FIG. 4) downstream of the mixer 15 so that they are efficiently mixed.

[0006]

However, in the conventional mixer illustrated in FIG. 5, mixing can be ensured by reducing the spread angle of the mixer, but there is a problem that the total length becomes long and the weight becomes large. It was On the contrary, when the spread angle was increased, the flow could be separated and sufficient mixing properties could not be obtained.

In order to solve this problem, the inventors of the present application have provided a mixer with a hole in the partition wall (Japanese Patent Application No. 4-308215) and a partition wall with a swirl (special characteristics). Japanese Patent Application No. 5-118819), which promotes mixing and swirling due to the shape of the partition wall (Japanese Patent Application No. 6-278132).
No.), a partition having a hole for adding a swirling flow (Japanese Patent Application No. 6-311048), etc.

[0008] However, the mixing of the fan flow and the core flow is important for improving the thrust, improving the combustion performance of the afterburner, etc., but the conventional mixer described above is still insufficient, and further mixing is promoted. Was needed. That is, in the conventional mixer, since the mixing of the fan flow and the core flow is insufficient, the jet thrust is reduced due to the loss at the time of mixing,
There are problems that efficient combustion by an afterburner is difficult, the velocity of the jet jet near the center is high, and noise proportional to the velocity cannot be reduced.

The present invention has been made to solve such a problem. That is, the object of the present invention is to further promote the mixing of the fan flow and the core flow, whereby the thrust can be improved, the combustion efficiency of the afterburner can be improved, and the noise due to the jet jet can be reduced. An object is to provide a fluid mixing device for an engine.

[0010]

According to the present invention, a core flow and a bypass flow are provided in a fluid mixing device of a jet engine having a core flow passing through a compressor, a combustor and a turbine, and a bypass flow bypassing the core flow. A plurality of mixers, which are provided in the cylindrical partition wall that divides the space and guide the core flow and the bypass flow alternately in the circumferential direction to the outside and the inside, are mixed, and the plurality of mixers are continuous in the axial direction of the engine and mutually It is arranged in a staggered position in the circumferential direction.
Provided is a fluid mixing device for a jet engine, characterized in that the core flow and the bypass flow are alternately guided to the outer side and the inner side at different circumferential positions.

According to the above-described structure of the present invention, since a plurality of mixers arranged in the axial direction of the engine and displaced from each other in the circumferential direction are provided, the upstream mixers are used as in the conventional fan. The flow and the core flow can be mixed, and the partially mixed fan flow and the core flow can be mixed again in the downstream mixer, so that the mixing of the fan flow and the core flow can be further promoted.

According to a preferred embodiment of the present invention, the mixer is composed of an upstream small mixer and a downstream large mixer, and both the small mixer and the large mixer have an enlarged diameter portion in which the diameter on the downstream side gradually increases. And the gradually decreasing diameter-reduced portion are alternately located in the circumferential direction, and the diameter-enlarged portion and the diameter-reduced portion are opposite to each other. With this configuration, the expanded diameter portion and the reduced diameter portion of the small mixer and the large mixer are positioned opposite to each other, so that the mixed flow of a part of the core flow guided to the outside by the small mixer and the bypass flow is Can be mixed again with the remaining core flow that has been guided inward and passed through the small mixer, and mixing can be performed more effectively.

Further, it is preferable that the partition walls constituting the mixer are inclined in the same rotation direction. With this configuration, a strong swirling flow can be generated at the same time as mixing, and mixing can be promoted. Furthermore, it is preferable that the partition wall forming the mixer is provided with a plurality of through holes or louvers. With this configuration, the mixing can be promoted also by the fan flow and the core flow that have passed through the through hole or the louver.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, common parts are denoted by the same reference numerals. FIG. 1 is a partial configuration diagram of a jet engine provided with a fluid mixing device according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG.
FIG. 3 is a partial perspective view of a fluid mixing device according to the present invention. 1 and 2, the jet engine of the present invention has a core flow 14 that passes through the compressor, the combustor 4 and the turbine 5 and a bypass flow 13 that bypasses the core flow 14 as in FIG. The cylindrical partition wall 1 is between the bypass flow 14 and the bypass flow 14.
Partitioned by 7. In this figure, 10 is an outer duct, 11 is a liner, and 16 is a tail cone.

The jet engine fluid mixing apparatus 20 of the present invention comprises an upstream small mixer 22 and a downstream large mixer 24.
And a front edge is attached to a cylindrical partition wall 17 that divides the core flow 14 and the bypass flow 13, respectively, so that the core flow 14 and the bypass flow 13 are alternately guided to the outer side and the inner side in the circumferential direction to be mixed. Has become. In addition, the mixer 22,
24 are continuously arranged in the axial direction of the engine as shown in FIGS. 1 and 3, and are arranged so as to be displaced from each other in the circumferential direction as shown in FIG.

With the above-described structure, the plurality of mixers 22 and 24 which are continuous in the axial direction of the engine and are displaced from each other in the circumferential direction allow the fan on the upstream side (small mixer 22) to operate in the same manner as the conventional fan. The flow 13 and the core flow 14 can be mixed, and the partially mixed fan flow 13 and the core flow 14 can be mixed again in the downstream mixer (large mixer 24) to further promote the mixing of the fan flow and the core flow. can do.

In FIG. 2, the small mixer 22 and the large mixer 2 are shown.
The expanded diameter portions 22a, 24a and the reduced diameter portions 22b, 24b of 4 are
Each of them is provided at 15 places in total, separated by 24 ° in the circumferential direction. In addition, as shown in FIGS. 1 and 3, the small mixer 22 and the large mixer 24 both have a diameter-increasing portion 22a, 24a whose diameter on the downstream side gradually increases and a diameter-decreasing portion 22b, 24b which gradually decrease.
And are located alternately in the circumferential direction. Further, as shown in FIG. 2, the reduced diameter portion 24b of the large mixer is located on the downstream side of the enlarged diameter portion 22a of the small mixer 22, and the reduced diameter portion 22 of the small mixer 22 is located.
The enlarged diameter portion 24a of the large mixer is located on the downstream side of b, and the enlarged diameter portions 22a, 24a and the reduced diameter portions 22b, 24b are arranged opposite to each other.

With this configuration, since the expanded diameter portions 22a, 24a and the reduced diameter portions 22b, 24b of the small mixer 22 and the large mixer 24 are located opposite to each other, the core flow 14 guided to the outside by the small mixer 22 is small. A mixed flow of a part and the bypass flow 13,
The large mixer 24 can guide the inside and mix again with the remaining core flow that has passed through the small mixer 22, so that the mixing can be performed more effectively.

2 and 3, the cross-sectional shape (flow path shape) of the expanded diameter portion and the reduced diameter portion is formed in a corrugated shape, but the present invention is not limited to this, and a rectangular shape, a triangular shape, a trapezoidal shape. And so on. In addition, the small mixer 22 and the large mixer 24
The expanded diameter portions 22a, 24a and the reduced diameter portions 22b, 24b are formed in the same number, but the number is not limited to this, and one may be increased. Further, in the above-described embodiment, the expanded diameter portion 22
Although the a and 24a and the reduced diameter portions 22b and 24b are arranged opposite to each other, they may not be arranged completely opposite to each other but may be arranged to be slightly shifted.

Further, the partition walls forming the mixers 22 and 24 may be inclined in the same rotation direction. With this configuration, a strong swirling flow can be generated simultaneously with mixing,
Mixing can be promoted. Furthermore, the mixer 2
A plurality of through-holes or louvers may be provided in the partition walls forming 2, 24. With this configuration, the mixing can be promoted also by the fan flow and the core flow that have passed through the through hole or the louver.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0022]

As described above, the fluid mixing device for a jet engine according to the present invention can further promote the mixing of the fan flow and the core flow, which improves thrust and combustion efficiency of the afterburner. It has excellent effects such as reduction of noise due to jet jet flow.

[Brief description of the drawings]

FIG. 1 is a partial configuration diagram of a jet engine including a fluid mixing device according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partial perspective view of a fluid mixing device according to the present invention.

FIG. 4 is a configuration diagram of a jet engine having a conventional mixer.

FIG. 5 is a partial perspective view of a conventional mixer.

[Explanation of symbols]

 1 Aircraft Engine (Jet Engine) 2 Fan 3 Compressor 4 Combustor 5 Turbine 6 Afterburner 7 Frame Holder 8 Fuel Nozzle 9 Spark Plug 10 Outer Duct 11 Liner 12 Exhaust Nozzle 13 Bypass Flow (Fan Flow) 14 Core Flow 15 Mixer (Mixture) 16 tail cone 17 partition wall 20 fluid mixing device 22 small mixer 22a expanded diameter portion 22b reduced diameter portion 24 large mixer 24a expanded diameter portion 24b reduced diameter portion

Claims (4)

[Claims] 1. A fluid mixing apparatus for a jet engine having a core flow passing through a compressor, a combustor, and a turbine, and a bypass flow bypassing the core flow, the cylindrical flow partition being provided between the core flow and the bypass flow.
A plurality of mixers for guiding the core flow and the bypass flow alternately in the circumferential direction to the outside and the inside and mixing the mixers are provided.
It is arranged so as to be continuous in the axial direction of the engine and offset from each other in the circumferential direction, so that the core flow and the bypass flow are alternately guided to the outside and the inside at different circumferential positions. Jet engine fluid mixing device. 2. The mixer comprises a small mixer on the upstream side and a large mixer on the downstream side, and the small mixer and the large mixer each have a diameter-increasing portion on the downstream side and a diameter-decreasing portion on the downstream side. 2. The fluid mixing device for a jet engine according to claim 1, wherein the enlarged diameter portion and the reduced diameter portion are located alternately in the direction, and are located opposite to each other. 3. The fluid mixing device for a jet engine according to claim 1, wherein the partition walls forming the mixer are inclined in the same rotation direction. 4. The fluid mixing apparatus for a jet engine according to claim 1, wherein the partition wall forming the mixer is provided with a plurality of through holes or louvers.