JP2006010179A - Afterburner for aircraft engine and aircraft engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aircraft engine for enhancing flame holding performance without impairing ignitability of an afterburner for the aircraft engine. <P>SOLUTION: This afterburner has an exhaust duct 29 arranged in a rear part of an engine case, an annular gutter 33 arranged in the exhaust duct 29 and having an outer ring part 35 and an inner ring part 37, a spray bar 43 for injecting fuel in the rear direction along a surface of the outer ring part 35 and the inner ring part 37, and an igniter 47 for igniting by flying a spark to mixed gas including the fuel from a tip part. An outer cutout 51 is formed in the rear side vicinity of the tip part of the igniter 47 in the rear edge of the outer ring part 35. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to the technical field of aircraft engines, and more particularly to the technical field of aircraft engine afterburners that re-burn fuel to increase engine thrust.

  An aircraft engine afterburner, which is one of the elements of an aircraft engine mounted on an aircraft, increases the engine thrust by reburning fuel. Hereinafter, a conventional general aircraft engine afterburner will be described. Briefly described.

  That is, an exhaust duct is disposed at the rear part of the engine case in the aircraft engine, and an annular gutta (frame holder) capable of forming a circulating flow (vortex flow) of the mixed gas behind in the exhaust duct. ) Is arranged. Here, the gutta has an outer ring part on the outer side and an inner ring part on the inner side. Moreover, the said gutta is comprised so that a partial cross-sectional shape may expand in a V shape toward back.

  In the exhaust duct, a plurality of spray bars for injecting fuel in the backward direction along the surfaces of the outer ring part and the inner ring part are arranged at equal intervals. Further, an igniter is disposed in the vicinity of any one of the spray bars in the exhaust duct, and this igniter ignites by sparking a mixed gas containing fuel from the tip, The tip of the igniter penetrates the outer ring from the front side.

  Therefore, during the operation of the aircraft engine, the high temperature gas discharged from the main flow path in the aircraft engine and the low temperature air discharged from the bypass flow path in the aircraft engine are mixed to form a mixed gas from the aircraft engine. By exhausting backward, the aircraft can obtain engine thrust.

  Further, when fuel is injected backward along the surfaces of the outer ring portion and the inner ring portion by the spray bar, a circulating flow of mixed gas containing fuel is formed behind by the gutter. Then, by sparking and igniting the mixed gas containing fuel from the tip of the igniter, the fuel can be reburned to form a flame behind the gutter. Thereby, the engine thrust can be increased by expanding and accelerating the mixture exhausted backward from the aircraft engine.

In addition, there exists a thing shown to patent document 1 as a prior art relevant to this invention.
JP-A-9-119346

  By the way, in order to stably form a flame behind the gutta and improve the flame holding performance of the aircraft engine afterburner, it is necessary to lengthen the time that the fuel stays in the vicinity of the gutta. For this reason, it is necessary to increase the size of the gutta in the engine axial direction (front-rear direction) of the aircraft engine to increase the scale of the circulating flow of the mixed gas.

  On the other hand, as the scale of the mixed gas circulation flow increases, the circulation flow center (vortex flow center) of the mixed gas circulation flow moves rearward, so that the front end of the igniter and the circulation flow of the mixed gas are transferred. The distance from the center of the circulation flow becomes longer. For this reason, when the flame holding performance of the aircraft engine afterburner is increased, sufficient fuel cannot be returned to the vicinity of the tip of the igniter on the circulating flow of the mixed gas. Ignition performance deteriorates.

  That is, in the conventional aircraft engine afterburner, it is extremely difficult to improve the flame holding performance of the aircraft engine afterburner without impairing the ignition performance of the aircraft engine afterburner. is there.

In the invention according to claim 1, in the afterburner for an aircraft engine, which is one of the elements of the aircraft engine and re-burns the fuel to increase the engine thrust,
An exhaust duct disposed at the rear of an engine case in the aircraft engine;
It is arranged in the exhaust duct, has an outer ring part on the outside, an inner ring part on the inside, and is configured so that the partial cross-sectional shape expands in a V shape toward the rear, An annular gutta capable of forming a circulating flow of mixed gas;
A spray bar for injecting fuel backward along the surfaces of the outer ring part and the inner ring part;
An igniter that has a tip portion penetrating the outer ring portion from the front side and ignites a spark from the tip portion against a mixed gas containing fuel; and
An outer notch is formed in the vicinity of the rear side of the front end portion of the igniter at the rear edge of the outer ring portion.

  According to the invention specific matter of claim 1, during operation of the aircraft engine, the hot gas discharged from the main flow path in the aircraft engine and the low-temperature air discharged from the bypass flow path in the aircraft engine are mixed. Thus, the aircraft can obtain engine thrust by being exhausted backward from the aircraft engine as a mixed gas.

  Further, when fuel is injected backward along the surfaces of the outer ring part and the inner ring part by the spray bar, a circulating flow of mixed gas containing fuel is formed backward by the gutter. Then, by sparking and igniting the mixed gas containing fuel from the tip of the igniter, the fuel can be reburned to form a flame behind the gutter. Thereby, the engine thrust can be increased by expanding and accelerating the mixture exhausted rearward from the aircraft engine (general operation of the aircraft engine afterburner).

  In addition to the general operation of the aircraft engine afterburner, the outer notch is formed in the vicinity of the rear side of the front end of the igniter at the rear edge of the outer ring portion. The circulating flow center (vortex flow center) in a part of the circulating flow of the mixed gas formed in the above can be locally brought close to the tip of the igniter.

  In the invention according to claim 2, in addition to the matters specifying the invention according to claim 1, an inner notch facing the outer notch is formed at the rear edge of the inner ring portion. Features.

  According to the invention specific matter of claim 2, in addition to the action of the invention specific matter of claim 1, the inner notch facing the outer notch is formed at the rear edge of the inner ring portion. Therefore, the circulating flow center in a part of the circulating region of the mixed gas formed behind the inner ring portion can be locally brought close to the tip of the igniter.

According to a third aspect of the present invention, in addition to the specific matters of the first or second aspect, the exhaust duct is disposed so as to surround the gutta and the mixed gas is supplied to the outer ring. An outer guide that leads backward along the surface of the part;
An inner guide disposed in the exhaust duct so as to be surrounded by the gutta and guiding the mixed gas in a backward direction along the surface of the inner ring portion;
It is characterized by comprising.

  According to the invention specific matter of the third aspect, in addition to the action of the invention specific matter of the first or second aspect, the outer ring portion and the inner ring are used to supply the mixed gas by the outer guide and the inner guide. Since it is guided backwards along the surface of the part, it is possible to stably form a circulation flow behind the outer ring part and the inner ring part, and the time for the fuel to stay in the vicinity of the gutter is long. Become.

  According to a fourth aspect of the present invention, the aircraft engine afterburner according to any one of the first to third aspects is provided.

  In invention of Claim 4, there exists an effect | action similar to the effect | action by the invention specific matter as described in the claim in any one of Claims 1-3.

  According to the invention described in any one of claims 1 to 4, the center of the circulating flow in a partial region in the circulating flow of the mixed gas formed behind the outer ring portion is locally provided. Therefore, even if the size of the gutter is increased in the engine axial direction and the scale of the circulating flow of the mixed gas is increased, sufficient fuel rides on the circulating flow of the mixed gas and the above-mentioned You can return to the vicinity of the tip of the igniter. Therefore, the flame holding performance of the aircraft engine afterburner can be easily and easily increased without impairing the ignition performance of the aircraft engine afterburner. In particular, according to the invention described in any one of claims 2 to 4, the center of the circulation flow in a part of the circulation flow of the mixed gas formed behind the inner ring portion is provided. Since the tip of the igniter can be locally approached, more sufficient fuel can ride on the circulating flow of the mixed gas and return to the vicinity of the tip of the igniter, thereby further improving the above-described effect. .

  According to invention of Claim 3 or Claim 4, a circulation flow can be stably formed in the back of the said outer ring part and the said inner ring part, respectively, and the time for which a fuel stays in the vicinity of the said guttata Therefore, the flame holding performance of the aircraft engine afterburner can be further enhanced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5.

Here, FIG. 1 is an enlarged view of a portion I in FIG. 5, FIG. 2 is a view taken along line II-II in FIG. 1, and FIG. 3 is an aircraft according to an embodiment of the present invention. FIG. 4 is a schematic partial rear view of an afterburner for an engine, FIG. 4 is a diagram for explaining a circulating flow of a mixed gas formed at the rear of a gutter, and FIG. 5 is an embodiment of the present invention. It is a typical sectional side view of the aircraft engine concerned. In the drawings, “F” indicates the forward direction, and “R” indicates the backward direction.
As shown in FIG. 5, an aircraft engine 1 according to an embodiment of the present invention is mounted on an aircraft and includes a cylindrical engine case 3 as a main body. A main flow path 5 through which high-temperature gas flows is formed in the engine case 3, and a bypass flow path 7 through which low-temperature air flows is formed outside the main flow path 5 in the engine case 3.

  A fan 9 for sending air to the main flow path 5 and the bypass flow path 7 is disposed at the front part in the engine case 3. The fan 9 has a fan rotor 9 a that can rotate about the engine axis C. I have. An inlet cone 11 is disposed at the front center of the fan rotor 9a.

  A compressor 13 for compressing the air sent into the main flow path 5 is disposed on the rear side of the fan 9 in the engine case 3, and the compressor 13 is rotatable about the engine axis C. A compressor rotor 13a is provided. A combustor 15 for combusting fuel in compressed air is disposed behind the compressor 13 in the engine case 3.

  A high-pressure turbine 17 is disposed on the rear side of the combustor 15 in the engine case 3, and the high-pressure turbine 17 is driven by the expansion of high-temperature gas from the combustor 15 and interlocks with the compressor 13. And a high-pressure turbine rotor 17a that can rotate around the engine axis C. Here, the high-pressure turbine rotor 17a is integrally connected to the compressor rotor 13a.

  A low-pressure turbine 19 is disposed on the rear side of the high-pressure turbine 17 in the engine case 3, and the low-pressure turbine 19 is driven by expansion of high-temperature gas and drives the fan 9 in conjunction with it. And a low-pressure turbine rotor 19a rotatable about the engine axis C. Here, the low-pressure turbine rotor 19 a is integrally connected to the fan 9. A tail cone 21 is disposed at the rear center of the low-pressure turbine rotor 19a.

  A mixer 23 is disposed at the rear of the engine case 3, and this mixer 23 mixes the hot gas discharged from the main flow path 5 and the low-temperature air discharged from the bypass flow path 7. . An after burner 25 is disposed on the rear side of the mixer 23 to increase the engine thrust by recombusting the fuel. On the rear side of the after burner 25, a mixed gas of high-temperature gas and low-temperature air is provided. As shown in FIG.

  Next, the afterburner (afterburner for aircraft engine) 25 which is one of the components of the aircraft engine 1 will be described in detail.

  As shown in FIGS. 1 and 3, an exhaust duct 29 is disposed at the rear of the engine case 3, and the exhaust duct 29 is connected to an exhaust nozzle 27. A cylindrical liner 31 is disposed in the exhaust duct 29.

  An annular gutta (frame holder) 33 capable of forming a circulating flow (vortex flow) S (see FIG. 4) of the mixed gas is disposed in the liner 31 at the rear. Here, the gutta 33 has an outer ring portion 35 on the outer side and an inner ring portion 37 on the inner side. Further, the gutta 33 is configured such that the partial cross-sectional shape expands in a V shape toward the rear.

  In the vicinity of the outer ring portion 35 in the liner 31, an annular outer guide 39 that guides the mixed gas in the rearward direction along the surface of the outer ring portion 35 is disposed so as to surround the gutter 33. The front / rear position of the rear edge of the guide 39 (the position of the aircraft engine 1 in the engine axial direction) is the same as the front / rear position of the rear edge of the outer ring portion 35. An annular inner guide 41 that guides the mixed gas in the rearward direction along the surface of the inner ring portion 37 is disposed in the vicinity of the inner ring portion 37 in the liner 31 so as to be surrounded by the gutta 33. The front and rear positions of the rear edge of the inner guide 41 are the same as the front and rear positions of the rear edge of the inner ring portion 37.

  In the exhaust duct 29, a plurality of spray bars 43 for injecting fuel rearward along the surfaces of the outer ring portion 35 and the inner ring portion 37 are arranged at equal intervals via a bracket 45 (not shown in FIG. 3). Has been. Here, each spray bar 43 passes through the liner 31 and the outer guide 39, and the tip of each spray bar 43 is located in the vicinity of the front side of the gutta 33. Each spray bar 43 includes a fuel injection hole 43a in the vicinity of the tip.

  An igniter 47 is disposed in the exhaust duct 29 in the vicinity of the rear side of one of the spray bars 43 via a fixed sleeve 49, and this igniter 47 blows sparks to the mixed gas containing fuel from the tip. To ignite. Here, the igniter 47 penetrates the liner 31, and the tip of the igniter 47 penetrates the outer guide 39 and the outer ring portion 35 from the front side.

  As shown in FIGS. 1, 2, and 4 (b), a rectangular outer notch 51 is formed in the vicinity of the rear side of the front end portion of the igniter 47 at the rear edge of the outer ring portion 35. The width of the outer notch 51 is larger than the diameter of the tip of the igniter 47. As shown in FIG. 4 (c), in addition to the outer notch 51 being formed at the rear edge of the outer ring portion 35, a rectangular inner that faces the outer notch 51 at the rear edge of the inner ring portion 37. A notch 53 may be formed.

  Next, the operation of the embodiment of the present invention will be described.

  When the fan rotor 9a and the compressor rotor 13a are rotated around the engine axis C by operating an appropriate starter device (not shown), air can be sent to the main flow path 5 and the bypass flow path 7 by the fan 9, The air sent into the main flow path 5 by the compressor 13 can be compressed. Next, when fuel is combusted in the air compressed by the combustor 15 to generate high-pressure high-temperature gas, the high-pressure turbine 17 and the low-pressure turbine 19 are driven by the expansion of the high-temperature gas, and the compressor 13 and the fan are driven. 9 can be driven in conjunction with each other. The aircraft engine 1 can be operated by continuously performing a series of operations (drive of the fan 9, drive of the compressor 13, combustion by the combustor 15, and drive of the high pressure turbine 17 and the low pressure turbine 19). it can.

  Further, during the operation of the aircraft engine 1, the high-temperature gas discharged from the main flow path 5 and the low-temperature air discharged from the bypass flow path 7 are mixed by the mixer 23, and the mixed gas is rearward from the exhaust nozzle 27. By being exhausted, the aircraft can obtain engine thrust.

  Further, when fuel is injected backward along the surfaces of the outer ring portion 35 and the inner ring portion 37 by the spray bar 43, a mixed gas circulation flow S containing fuel is formed by the gutta 33. Here, in order to guide the mixed gas backward along the surfaces of the outer ring part 35 and the inner ring part 37 by the outer guide 39 and the inner guide 41, the mixed gas circulates behind the outer ring part 35 and the inner ring part 37, respectively. The flow S can be stably formed, and the time during which the fuel stays in the vicinity of the gutter 33 is increased. Then, by sparking the mixed gas containing fuel from the tip of the igniter 47 and igniting it, the fuel can be reburned and a flame can be formed behind the gutta 33. Thereby, the engine exhaust force can be increased by expanding and accelerating the mixture exhausted rearward from the exhaust nozzle 27 (a general action of the afterburner 25).

  In addition to the general action of the afterburner 25, an outer notch 51 is formed in the vicinity of the rear side of the front end of the igniter 47 at the rear edge of the outer ring portion 35, so that as shown in FIG. The circulation flow center (vortex flow center) Sb in a part of the circulation flow S of the mixed gas formed behind the outer ring portion 35 can be locally brought close to the tip of the igniter 47.

  As shown in FIG. 4C, when the outer notch 51 is formed at the rear edge of the outer ring portion 35 and the inner notch 53 is formed at the rear edge of the inner ring portion 37, the outer ring portion 35 The circulating flow center Sb in a part of the circulating flow S of the mixed gas formed behind the ring portion 35 and the inner ring portion 37 can be made closer to the tip of the igniter 47 locally.

  As shown in FIG. 4 (a), the circulation flow center Sb in the most part of the mixed gas circulation flow S formed behind the outer ring portion 35 and the inner ring portion 37 is the circulation of the mixed gas. The distance from the tip of the igniter 47 is maintained according to the scale of the flow S. Further, the circulating flow center Sb of the mixed gas circulating flow S shown in FIGS. 4A, 4B, and 4C is obtained by CFD (Computational Fluid Dynamics) analysis.

  As described above, according to the embodiment of the present invention, the circulation flow center Sb in a part of the circulation flow S of the mixed gas formed behind the outer ring portion 35 is locally brought close to the tip of the igniter 47. Therefore, even if the size of the gutta 33 is increased in the engine axial direction and the scale of the circulating flow S of the mixed gas is increased, sufficient fuel rides on the circulating flow S of the mixed gas to the vicinity of the tip of the igniter 47. I can come back. Therefore, the flame holding performance of the afterburner 25 can be easily and easily increased without impairing the ignition performance of the afterburner 25.

  In particular, when the outer notch 51 is formed at the rear edge of the outer ring portion 35 and the inner notch 53 is formed at the rear edge of the inner ring portion 37, the rear of the outer ring portion 35 and the inner ring portion 37. Since the circulating flow center Sb in a part of the region of the mixed gas circulation flow S formed in each can be further brought closer to the tip of the igniter 47, more sufficient fuel is supplied to the mixed gas circulation flow S. It is possible to ride and return to the vicinity of the tip of the igniter 47, and the above-described effects are further improved.

  In addition, the circulation flow S can be stably formed behind the outer ring part 35 and the inner ring part 37, and the time during which the fuel stays in the vicinity of the gutta 33 becomes longer, so that the flame holding performance of the after burner 25 is improved. It can be further increased.

  In addition, this invention is not restricted to description of embodiment of the above-mentioned invention, It can implement in another various aspect by making an appropriate change.

It is an enlarged view of the I section in FIG. It is the figure along the II-II line in FIG. It is a typical partial rear view of the afterburner for aircraft engines concerning the embodiment of the present invention. It is a figure explaining the circulation flow of the mixed gas formed in the back of a gutta. 1 is a schematic cross-sectional side view of an aircraft engine according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aircraft engine 5 Main flow path 7 Bypass flow path 25 Afterburner (afterburner for aircraft engines)
29 Exhaust duct 31 Liner 33 Gutta 35 Outer ring part 37 Inner ring part 39 Outer guide 41 Inner guide 43 Spray bar 47 Igniter 51 Outer notch 53 Inner notch

Claims (4)

In an aircraft engine afterburner, which is one of the elements of an aircraft engine and reburns fuel to increase engine thrust,
An exhaust duct disposed at the rear of an engine case in the aircraft engine;
It is arranged in the exhaust duct, has an outer ring part on the outside, an inner ring part on the inside, and is configured so that the partial cross-sectional shape expands in a V shape toward the rear, An annular gutta capable of forming a circulating flow of mixed gas;
A spray bar for injecting fuel backward along the surfaces of the outer ring part and the inner ring part;
An igniter that has a tip portion penetrating the outer ring portion from the front side and ignites a spark from the tip portion against a mixed gas containing fuel; and
An afterburner for an aircraft engine, wherein an outer notch is formed in the vicinity of the rear side of the tip portion of the igniter at the rear edge of the outer ring portion.   The afterburner for an aircraft engine according to claim 1, wherein an inner notch facing the outer notch is formed at a rear edge of the inner ring portion. An outer guide disposed in the exhaust duct so as to surround the gutta and guiding the mixed gas backward along the surface of the outer ring portion;
An inner guide disposed in the exhaust duct so as to be surrounded by the gutta and guiding the mixed gas in a backward direction along the surface of the inner ring portion;
The afterburner for an aircraft engine according to claim 1 or 2, characterized by comprising:   An aircraft engine comprising the afterburner for an aircraft engine according to any one of claims 1 to 3.

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