JP2004027854A - Turbofan engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbofan engine capable of increasing the intake air flow of a fan single-stage moving blade without increasing the diameter of a fan and the inside diameter of a casing, thereby increasing bypass ratio to achieve low fuel consumption and low noise while reducing engine weight. <P>SOLUTION: The turbofan engine has the fan single-stage moving blade 2 for admitting air, and a spinner 4 for driving the fan single-stage moving blade to rotate it. The spinner 4 has a spiral vane 6 on its front face. The spiral vane 6 extends radially outwardly and spirally from its axis X and sucks air from the front face of the spinner to supply the air to the fan single-stage moving vane. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a turbofan engine having a high bypass ratio and capable of reducing fuel consumption and noise.
[0002]
[Prior art]
FIG. 3 is a schematic configuration diagram of the aircraft engine 51 (turbojet engine). As shown in this figure, the turbojet engine includes a fan 52 for taking in air, a compressor 53 for compressing the taken-in air, a combustor 54 for burning fuel with the compressed air, and a fan 52 and a compressor for burning gas from the combustor 54. A turbine 55 for driving the engine 53, an afterburner 56 for reburning to increase the thrust, and the like.
[0003]
The afterburner 56 has a triangular cross section and the like, and comprises a frame holder (flame holder) 57 for forming a circulation area downstream and performing flame holding, a fuel nozzle 58 for ejecting fuel, an ignition plug 59 and the like, and an outer duct. The gas is ejected from an exhaust nozzle 62 through a liner 61 inside 60 to increase the thrust.
[0004]
In the turbojet engine described above, the one that enlarges the fan 52 for taking in air and increases the bypass ratio is called a “turbofan engine”. The bypass ratio is a flow ratio (bypass flow / core flow) of the bypass flow that bypasses the air flow (core flow) flowing into the core engine (the compressor 53, the combustor 54, and the turbine 55 described above). The larger the value, the lower the flow velocity of the exhaust jet, which is effective in reducing noise and fuel consumption.
[0005]
[Problems to be solved by the invention]
However, in the turbofan engine described above, when the bypass ratio is increased, there is a problem that the first stage blade of the fan (the front-row fan) and the inner diameter of the casing surrounding the same become large, and the weight of the engine increases.
[0006]
That is, the fan one-stage rotor blade 52a having a structure embedded in the spinner 63 of the turbofan engine requires a certain hub / tip ratio (entrance hub diameter / inlet tip diameter) because of the embedded structure, and is equivalent to the area of the spinner. The fan entrance area becomes smaller.
Therefore, in order to increase the bypass ratio in order to achieve low fuel consumption and low noise, the diameter of the fan and the inside diameter of the casing must be further increased, and the weight of the engine increases.
[0007]
The present invention has been made to solve such a problem. That is, an object of the present invention is to increase the suction air flow rate of the fan one-stage rotor blade without increasing the fan diameter and the casing inner diameter, thereby increasing the bypass ratio, achieving low fuel consumption and low noise. Another object of the present invention is to provide a turbofan engine capable of reducing the engine weight while reducing the engine weight.
[0008]
[Means for Solving the Problems]
According to the present invention, there is provided a fan one-stage rotor blade (2) for taking in air, and a spinner (4) for rotating and driving the fan one-stage rotor blade, the spinner being located radially outward from its axis. And a spiral blade (6) extending spirally to draw air from the front surface of the spinner and supply the air to the one-stage moving blade of the fan.
[0009]
According to a preferred embodiment of the present invention, the first stage rotor blade (2) and the spinner (4) are integrally connected, and the spiral blade (6) and the first stage rotor blade (2) have a blade surface. It is formed to connect smoothly.
[0010]
According to the configuration of the present invention, the spinner (4) spirally extends radially outward from the axis thereof and sucks air from the front surface of the spinner and supplies it to the fan one-stage blade (2). Therefore, air can also be sucked in from the front surface of the spinner, compressed and supplied to the first-stage moving blades (2) of the fan.
Therefore, the entire area in front of the engine becomes the air inflow area of the first stage rotor blade (2) as it is, so that the fan diameter can be reduced and the engine weight can be reduced.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description is omitted.
[0012]
FIG. 1 is a partial configuration diagram of a turbofan engine of the present invention. In this figure, (A) shows the present invention, and (B) shows a conventional example. In each of the drawings, Z-Z denotes an engine rotation shaft, 12 and 12 'denote casing inner diameters, 13 denotes an inflow air flow, 14 denotes a core flow, and 15 denotes a bypass flow.
[0013]
As shown in FIG. 1A, the turbofan engine of the present invention includes a first-stage fan blade 2 for taking in air, and a spinner 4 for rotating the first-stage fan blade 2. The spinner 4 has a spiral blade 6 on the front surface. The spiral blade 6 spirally extends radially outward from the axis Z of the spinner 4, sucks air from the front surface of the spinner, compresses the air, and supplies the compressed air to the one-stage fan blade 2. The shape of the spiral blade 6 may be, for example, a spiral blade similar to the impeller shape of a mixed flow compressor or a radial flow compressor.
[0014]
The first-stage fan blade 2 and the spinner 4 are preferably connected integrally, and the spiral blade 6 and the first-stage fan blade 2 are formed such that their respective blade surfaces are smoothly connected.
[0015]
【Example】
An analysis for confirming the performance of the present invention was performed using the conventional configuration and the present invention shown in FIG. Compared to the conventional type (B), in the present invention (A), the rotor blades (the spiral blade 6 and the fan first-stage rotor blade 2) are provided from the engine center axis Z, and the outer diameter (12, 12 ′) of the engine is The present invention 12 is set to be about 5% smaller than the mold 12 '. In this analysis, the total pressure distribution and the total temperature distribution behind the first-stage fan blades 2 and 52a were made the same.
[0016]
FIG. 2 shows the speed triangle of the fan one-stage rotor blade as a result of the analysis in three cross sections (hub, mid, and tip). In the drawing, ABS1 and ABS2 indicate the absolute speeds of the inflow air and the outflow air, and REL1 and REL2 indicate the relative speeds of the inflow air and the outflow air.
[0017]
As can be seen from FIG. 2, the speed triangles of the mid and the chip are almost equal in the conventional type and the present invention. However, there is a difference in the speed triangle of the hub, and the turning angles θ and θ ′ (difference in the relative flow angle between the inlet and the outlet) for bending the flow are clearly smaller in the present invention. That is, in the conventional example, the turning angle θ ′ is about 50 °, whereas in the present invention, the turning angle θ is only about 20 °.
Therefore, in the present invention, it is understood that the load applied to the wing is lighter than that of the conventional type, and it is easy to realize such a wing. In addition, if the work of the spinner section can be increased and the flow rate can be increased by increasing the axial speed of the flow flowing into the spinner section, the outer diameter of the engine can be further reduced.
[0018]
According to the configuration of the present invention described above, since the spinner 4 has the spiral blade 6 that extends helically from the axis Z outward in the radial direction and sucks air from the front surface of the spinner and supplies the air to the first-stage rotor blade 2, Air can also be sucked in from the front surface of the spinner, compressed and supplied to the first-stage moving blades 2 of the fan.
[0019]
Accordingly, since the entire area in front of the engine becomes the air inflow area of the first stage rotor blade 2 as it is, the suction air flow rate of the first stage rotor blade can be increased even if the fan diameter and the casing inner diameter are made smaller than before. As a result, it is possible to increase the bypass ratio, achieve low fuel consumption and low noise, and reduce the engine weight.
[0020]
It should be noted that the present invention is not limited to the above-described embodiments and examples, and it is needless to say that various changes can be made without departing from the spirit of the present invention.
[0021]
【The invention's effect】
As described above, the turbofan engine of the present invention can increase the suction air flow rate of the first-stage blade of the fan without increasing the fan diameter and the casing inner diameter, thereby increasing the bypass ratio and improving fuel efficiency. It has excellent effects such as achieving low noise and reducing engine weight.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a turbofan engine of the present invention.
FIG. 2 is an explanatory diagram of a turbofan engine of the present invention.
FIG. 3 is a configuration diagram of a conventional turbofan engine.
[Explanation of symbols]
Z-Z engine rotation axis,
2 1-stage rotor blade, 4 spinner, 6 spiral blade 12, 12 'casing inner diameter, 13 flow of inflow air,
14 core flow, 15 bypass flow,
51 aircraft engines (jet engines),
52 fan, 52a, 53 compressor, 54 combustor,
55 turbines, 56 afterburners,
57 frame holder (flame holder),
58 fuel nozzle, 59 spark plug,
60 outer duct, 61 liner,
62 exhaust nozzle, 63

Claims (2)

A fan one-stage blade for taking in air (2) and a spinner (4) for rotating and driving the fan one-stage blade are provided, and the spinner spirally extends radially outward from its axis. A turbofan engine having a spiral blade (6) for sucking air from a front surface of a spinner and supplying the air to a first stage rotor blade. The one-stage fan blade (2) and the spinner (4) are integrally connected, and the spiral blade (6) and the one-stage fan blade (2) are formed so that the blade surfaces are smoothly connected. The turbofan engine according to claim 1, wherein:

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