JP2006322394A - Exhaust pipe structure used for turbine engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce temperature of high speed exhaust gas discharged from an exhaust pipe used for a turbine engine of a small size vertical take-off and landing aircraft. <P>SOLUTION: An exhaust pipe structure is provided with a first duct 30 in which exhaust gas discharged from a turbine engine circulates and a second duct 40 in which outside air around the turbine engine arranged to form a double pipe around the first duct 30 circulates. An opening part 30a discharging exhaust gas of the first duct 30 and an opening part 40a discharging outside air around the turbine engine of the second duct 40 are arranged to form a double pipe at roughly same position in a longitudinal direction, and the opening part 30a of the first duct 30 is formed to keep the distance from a center line to an outer circumference line in a cross section at a predetermined length or shorter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exhaust pipe mechanism used for a turbine engine of a vertical take-off and landing aircraft.

  Currently, automobiles are widely used. However, in an automobile, it is impossible to reach a destination in an area where a travelable ground or road is not provided. In order to solve this problem, an aircraft equipped with a propeller has been proposed. With such an aircraft, unlike a general aircraft, a runway is not required, and it is possible to reach a destination where a road or the like is not maintained. However, when parked, a space corresponding to the rotation area of the propeller is required, and it is impossible for the user to use it with the same feeling as an automobile.

  In view of such circumstances, there has been proposed a vertical take-off and landing aircraft that can be used as an automobile and that can be used in place of an automobile currently used and can carry passengers and cargo (see, for example, Patent Document 1). ).

Turbine engines are mainly used for vertical take-off and landing aircraft. In addition, the gas discharged | emitted from a turbine engine is high temperature. Therefore, in order to lower the temperature of the gas exhausted from the turbine engine, a duct is formed so as to form a double pipe around the exhaust pipe, and air is circulated by the louver around the inner pipe and exhausted from the turbine engine. There has been proposed an exhaust pipe structure of a gas turbine engine vehicle that lowers the temperature of the generated gas (see, for example, Patent Document 2).
JP 2004-82999 A No. 7-10044

  The vertical take-off and landing aircraft can take off and land by the thrust generated by the take-off and landing engine installed in the aircraft in a direction substantially perpendicular to the ground, and the thrust generated from the engine holds the aircraft in the air. More specifically, the vertical take-off and landing aircraft compresses and burns the air taken into the vertical take-off and landing engine, and discharges exhaust gas (high-speed exhaust gas) from the injection port (exhaust port) of the exhaust pipe (duct). Have gained.

  Here, a vertical take-off and landing aircraft, particularly a small vertical take-off and landing aircraft that can be replaced by an automobile, is required to be able to take off and landing in a narrow space. In addition, a turbine engine is mainly used as the vertical take-off and landing engine, and high-speed exhaust gas discharged from the exhaust pipe outlet is high in temperature, so it is necessary to consider the heat damage to the place of take-off and landing and the waiting person. However, in consideration of heat damage, if the takeoff and landing locations are greatly limited, the function as a small vertical takeoff and landing aircraft that can be replaced by an automobile cannot be fully exhibited.

  Accordingly, an object of the present invention is to more effectively lower the temperature of high-speed exhaust gas discharged from an exhaust pipe used in a turbine engine of a small vertical take-off and landing aircraft.

In order to solve such a problem, in the present invention, in an exhaust pipe mechanism used in a turbine engine, outside air around the turbine engine is introduced around an exhaust pipe (duct) through which exhaust exhausted from the turbine engine flows. Ducts for circulating the outside air around the turbine engine are arranged so as to form a double pipe, and the exhaust gas discharged from the duct is mixed with the outside air around the turbine engine, and the exhaust gas discharged from the turbine engine. The shape of the outlet of the duct through which the gas flows is easy to mix with the ambient air around the turbine engine. Thereby, the temperature of the high-speed exhaust gas discharged | emitted from the exhaust pipe (duct) used for the turbine engine of a small vertical take-off and landing aircraft can be reduced more effectively.

  Specifically, the first duct through which the exhaust discharged from the turbine engine circulates, and the second duct arranged so as to form a double pipe around the first duct and through which the outside air around the turbine engine circulates. And an opening for discharging the exhaust of the first duct and an opening for discharging the outside air around the turbine engine of the second duct are substantially in the same position in the longitudinal direction. The cross section of the opening of the first duct is represented by a region defined by a width of a predetermined length or less with a predetermined center line as a reference. .

  The exhaust pipe mechanism used in the above turbine engine is arranged so as to form a double pipe around the first duct through which the exhaust discharged from the turbine engine flows, and around the turbine engine. A second duct through which the outside air flows. The first duct is an exhaust pipe that discharges the gas compressed and burned inside the turbine engine, and thrust (lift) is generated by the gas (high-speed exhaust gas) discharged from the exhaust pipe.

  The second duct is arranged so as to form a double pipe around the first duct. The opening for discharging the exhaust of the first duct and the opening for discharging the outside air around the turbine engine of the second duct are arranged so as to form a double pipe at substantially the same position in the longitudinal direction. Note that the high-speed exhaust gas discharged from the first duct is discharged at a high speed. Therefore, with such a configuration, the ambient air around the turbine engine exhausted from the second duct is mixed by being guided by suction to the flow velocity of the high-speed exhaust gas exhausted from the first duct. The temperature of the exhaust gas can be lowered.

  Further, the cross section of the opening portion of the first duct is represented by an area determined with a width of a predetermined length or less with a predetermined center line as a reference. Here, the cross section of the opening of the first duct refers to a plane perpendicular to the direction in which the exhaust flows. The predetermined center line is a virtual line used when specifying the cross-sectional shape of the opening, and means a line passing through the center of the cross-sectional shape. The predetermined length refers to the distance over which ambient air around the turbine engine exhausted from the second duct reaches the center of the high-speed exhaust gas exhausted from the first duct. The width means a width based on the predetermined center line.

  Therefore, the cross section of the opening of the first duct is a closed region having a width with respect to a predetermined center line, and the width is a turbine discharged from the second duct to the center of the high-speed exhaust gas. It is a shape that requires a distance that the outside air around the engine can reach. As a result, the ambient air around the turbine engine is easily mixed up to the center of the high-speed exhaust gas, and the temperature of the high-speed exhaust gas can be effectively lowered. The predetermined center line may be plural. When there is one predetermined center line, a flat shape is configured with the center line as a reference. When the predetermined center line is, for example, two lines that intersect perpendicularly, it has a cross shape. By narrowing the width with respect to the predetermined center line, or by forming a shape that requires a plurality of predetermined center lines, the ambient air around the turbine engine is mixed to the center of the high-speed exhaust gas, and the temperature of the high-speed exhaust gas Can be lowered effectively.

The thrust of the turbine engine is proportional to the cross-sectional area of the opening of the duct. Therefore, even if the cross section of the opening of the first duct is circular, if the diameter of the circle is reduced, the outside air around the turbine engine discharged from the second duct is discharged from the first duct. However, since the cross-sectional area is reduced, sufficient thrust cannot be ensured. Therefore, for example, the cross-section of the opening of the first duct has the same area as the cross-sectional area in the case of a circular shape that has been widely used in the past, and is determined with a width of a predetermined length or less with a predetermined center line as a reference By making the shape represented by the region to be expressed, the temperature of the high-speed exhaust gas can be lowered while maintaining the thrust.

  The upper end of the first duct connected to the turbine engine is usually cylindrical, whereas the cross section of the opening of the first duct is determined with a width of a predetermined length or less with respect to a predetermined center line. The upper end and the opening are different shapes. Therefore, it is desirable that the central portion between the upper end portion of the first duct coupled to the turbine engine and the opening portion of the first duct be a streamline. By making the central portion of the first duct a streamline, the resistance of the exhaust fluid flowing in the first duct can be reduced.

  In addition to the above, the exhaust pipe mechanism used for the turbine engine includes a fan for flowing in the outside air around the turbine engine, and a part of the outside air around the turbine engine that has flowed in by the fan is It is good also as a structure which flows in into the said turbine engine and the external air around other turbine engines flows in into the said 2nd duct.

  The second duct is arranged so as to form a double pipe around the first duct. When the turbine engine includes a fan, for example, the second duct is placed around the turbine engine. By forming so as to cover, a part of the outside air around the turbine engine that has flowed in from the fan can flow into the second duct. The outside air around the turbine engine flowing through the second duct is sucked and guided to the flow velocity of the high-speed exhaust gas discharged from the first duct, and is mixed. The flow rate of the outside air flowing through the second duct increases by being configured to flow into this duct, and the mixing effect of the high-speed exhaust gas and the outside air around the turbine engine can be further enhanced. In addition, by projecting the upper end of the second duct from the fan, a part of the outside air around the turbine engine flowing in from the fan can be more efficiently flowed into the second duct.

  In addition to the above, the exhaust pipe mechanism used for the turbine engine has an opening for exhausting outside air around the turbine engine of the second duct extending beyond an opening for exhausting the exhaust of the first duct, And it can be set as the structure bent toward the said turbine engine side.

  With such a configuration, the outside air around the turbine engine discharged from the second duct is discharged toward the center of the high-speed exhaust gas discharged from the first duct. It becomes possible to further enhance the mixing effect between the air and the ambient air around the turbine engine. It should be noted that the extension of the opening for discharging outside air around the turbine engine of the second turbine beyond the opening of the first turbine means that the opening of the second turbine protrudes from the opening of the first turbine. It means that

  In the exhaust pipe mechanism used for the turbine engine, in addition to the above, the cross section of the opening portion of the first duct may have a shape in which a plurality of the predetermined center lines extend radially on the basis of the coupling point. The coupling point means a point where the predetermined center lines are coupled. For example, when three predetermined center lines extend radially from one coupling point as a reference, a Y shape having a predetermined width is obtained. A plurality of coupling points may be provided.

In the exhaust pipe mechanism used in the turbine engine, a cross section of the opening of the first duct may be an ellipse. When the cross section of the opening is elliptical, the distance from the center of the high-speed exhaust gas discharged from the first duct to the peripheral wall surface of the opening of the first duct is short, and the cross section is circular As compared with the above, the mixing effect of the high-speed exhaust gas and the ambient air around the turbine engine can be further enhanced. The cross section of the opening of the first duct is not limited to the above, and may be, for example, a rectangle or a star.

  ADVANTAGE OF THE INVENTION According to this invention, in the exhaust pipe mechanism used for a turbine engine, the temperature of the high speed exhaust gas discharged | emitted from the exhaust pipe used for a turbine engine can be reduced effectively.

  Next, an embodiment of an exhaust pipe mechanism used for a turbine engine according to the present invention will be described based on the drawings.

  FIG. 1 is a perspective view showing a schematic configuration of a small vertical take-off and landing aircraft. As shown in the figure, the small vertical take-off and landing aircraft includes a fuselage 200 and two turbine engines 100 installed on a side surface of the fuselage 200, and a pilot 300 can be boarded on the fuselage 200. And the exhaust pipe mechanism used for the turbine engine which concerns on a present Example can be mounted in a small vertical take-off and landing aircraft as shown in the figure. In this case, an exhaust pipe mechanism used for the turbine engine according to the present embodiment is mounted on the turbine engine 100 together with the turbine engine. As a result, the range of heat damage is greatly reduced as compared with the conventional case, and the function as a small vertical take-off and landing aircraft that can be replaced with an automobile can be sufficiently exhibited.

  2A is a side sectional view showing the configuration of the exhaust pipe mechanism used in the turbine engine according to this embodiment, and FIG. 2B is a sectional view seen from the duct outlet side. FIG. As shown in FIG. 2A, the exhaust pipe mechanism used for the turbine engine flows in and discharges the first duct 30 through which the exhaust discharged from the turbine engine main body 10 flows and the outside air around the turbine engine 100. The second duct 40 is provided, and the first duct 30 and the second duct 40 are arranged to form a double pipe. The opening 40a of the second duct 40 includes a bent portion 40b that extends from the opening 30a of the first duct 30 and bends inward.

2A, the first duct 30 includes an upper end 30c, a streamlined central portion 30b, and an opening 30a. The upper end 30c is connected to the turbine engine main body 10. . And as shown in FIG.2 (b), the opening part 30a is narrowly formed in the left-right direction of a paper surface compared with the upper end part 30c. In addition, the width | variety currently formed narrowly in the paper surface left-right direction is corresponded to the width | variety below predetermined length on the basis of the predetermined centerline in this invention.
In FIG. 3, FIG. 3 (a) is a cross-sectional view of the side as viewed from the right direction in FIG. 1, and FIG. 3 (b) is viewed from the duct outlet side of FIG. 3 (a). It is sectional drawing.

  The air flowing in from the air intake port 2 for taking in the air is compressed by the compressor 1, and the temperature rises accordingly. The compressed atmosphere is sent to the combustion chamber 3 where fuel is sprayed and the temperature rises further. Through the combustion chamber 3, the turbine 4 is rotated by the high-temperature and high-pressure gas, a part of the energy is converted into mechanical power, and the remaining energy is discharged from the duct 30 as high-speed exhaust gas (velocity energy), and thrust Is produced. In addition, the dotted line arrow of FIG. 1 shows the flow of the atmosphere, and the solid line arrow shows the flow of the high-speed exhaust gas.

Outside air around the turbine engine 100 flows from an outside air inflow portion 40 c provided at the upper part of the second duct 40. The outside air around the turbine engine 100 is guided to be sucked at the flow velocity of the high-speed exhaust gas discharged from the first duct 30 and is discharged from the outside air discharge port of the second duct 40. Outside air around the turbine engine 100 discharged from the second duct 40 is mixed with high-speed exhaust gas discharged from the first duct 30. As a result, the temperature of the high-speed exhaust gas discharged from the second duct 40 can be effectively lowered.

  FIG. 4 is a side view of the turbine engine 100 corresponding to FIG. 3, and FIG. 5 is a view as seen from AA in FIG. The one-dot chain line shown in FIG. 5 corresponds to the predetermined center line of the present invention. X corresponds to a width equal to or less than a predetermined length based on the predetermined center line in the present invention. The thrust generated from the turbine engine body 10 is proportional to the cross-sectional area Y. Therefore, outside air discharged from the second duct to the center of the high-speed exhaust gas discharged from the first duct while maintaining the cross-sectional area when the cross section of the opening of the duct used in the past is circular. By determining the predetermined width X, which is the distance that is spread over, the temperature of the high-speed exhaust gas discharged from the first duct 30 can be effectively lowered while maintaining the thrust.

  FIG. 6 shows a cross-sectional view at the opening of a conventionally used duct. In the conventional exhaust pipe mechanism as shown in FIG. 6, even if the first duct 30 and the second duct 40 are arranged so as to form a double pipe, the outside air around the turbine engine remains in the first duct 30. It is not mixed up to the center of the high-speed exhaust gas discharged from. Therefore, the mixing effect of the ambient air around the turbine engine and the high-speed exhaust gas cannot be sufficiently obtained, and as a result, the high-temperature portion P remains in the center of the high-speed exhaust gas (FIG. 7). The arrows in FIG. 7 indicate the flow of outside air discharged from the second duct 40. On the other hand, in this embodiment, as shown in FIG. 8, the outside air exhausted from the second duct 40 reaches the center of the high-speed exhaust gas exhausted from the first duct 30. The effect of mixing the outside air and high-speed exhaust gas increases. As a result, since the high temperature portion P as shown in FIG. 7 is not formed, the temperature of the high-speed exhaust gas can be effectively lowered.

  FIG. 9 is a table showing the relationship between the temperature drop near the outlet of the first duct 30 and the distance from the vicinity of the outlet. A dotted line shows the case where the cross section of the opening part of the 1st duct 30 currently used conventionally shown in FIG. 7 is circular. A solid line indicates the exhaust pipe mechanism of the present embodiment. As shown in the figure, when the cross section is circular (dotted line), the mixing effect of the outside air around the turbine engine and the high-speed exhaust gas cannot be sufficiently obtained, so a gentle descending line is drawn. On the other hand, in the exhaust pipe mechanism according to the present embodiment, a curve having a larger inclination than the dotted line is drawn. That is, in this embodiment, since the temperature of the high-speed exhaust gas can be lowered, the range where the heat damage of the high-speed exhaust gas reaches can be made extremely small.

  FIG. 10 is a side cross-sectional view showing the configuration when the exhaust pipe mechanism used in the turbine engine according to the present invention is used in a turbofan engine. Description of the same components as those in FIG. 2 is omitted. As shown in FIG. 10, the exhaust pipe mechanism according to the present embodiment flows in and discharges the outside air around the first duct 30 and the turbofan engine 101 through which the exhaust discharged from the turbofan engine body 20 flows. The second duct 40 is provided, and the first duct 30 and the second duct 40 are arranged to form a double pipe. The cross section of the opening 30a of the first duct 30 is formed, for example, in the same manner as in FIG.

  The turbofan engine main body 20 includes the fan 6, and the outside air inflow portion 40 c of the second duct 40 extends beyond the fan 6. Outside air around the turbofan engine 101 sucked from the fan 6 passes through the compressor 1, the combustion chamber 3, and the turbine 4 and is discharged as high-speed exhaust gas from the first duct 30. Further, a part of the outside air around the turbofan engine 101 sucked from the fan 6 is sent to the second duct 40, and is sucked and guided to the flow velocity of the high-speed exhaust gas discharged from the first duct 30. It is discharged from the opening 40a of the duct 40. The ambient air around the turbine engine discharged from the second duct 40 is mixed with the high-speed exhaust gas discharged from the first duct 30. As a result, the temperature of the high-speed exhaust gas discharged from the second duct 40 can be effectively lowered.

  FIG. 11 shows an example of an opening cross section of the first duct 30a. In the embodiment described above, as shown in the figure, the cross section of the opening 30a of the first duct 30 may have a cross shape as shown in FIG. 11, for example. By making the cross-sectional shape cross-shaped, the distance from the center of the high-speed exhaust gas discharged from the first duct to the peripheral wall surface of the opening of the first duct is shortened, and the high-speed exhaust gas and the turbine engine Therefore, the effect of mixing the high-speed exhaust gas and the ambient air around the turbine engine can be further enhanced. In FIG. 11, an alternate long and short dash line means a predetermined center line. In the present embodiment, there are two predetermined center lines, and the point where the predetermined center lines intersect corresponds to the coupling point. The cross-sectional shape of the opening of the first duct is not limited to the above. For example, when five predetermined center lines are provided radially with respect to the coupling point, the opening section of the first duct 30a has a star shape.

  FIG. 12 is a front view of a small vertical take-off and landing aircraft that gathers thrust generated by two engines by extending ducts. As shown in FIG. 1, the small vertical take-off and landing aircraft according to the present embodiment includes a fuselage 200 and two turbine engine bodies 10 installed on the side of the fuselage 200. A collecting pipe 31 is connected to each of the lower ends of the two turbine engine bodies 10. The high-speed exhaust gas discharged from the two turbine engine main bodies 10 flows in from the connection portions of the collecting pipes 31 to the respective turbine engine main bodies 10, and the high-speed exhaust gases merge in the middle of the flow path and are discharged from the openings 31a. Is done.

  The cross section of the opening 31a of the collecting pipe 31 is configured by the cross sectional shape shown in FIG. 2B or the cross sectional shape shown in FIG. Further, the turbine engine body 10 may be a turbofan engine 40 as shown in FIG. That is, the exhaust pipe mechanism used in the turbine engine according to the present embodiment is not limited to the small vertical take-off and landing aircraft integrated with the turbine engine as shown in FIG. 1, but the thrust generated by the two engines as shown in FIG. It can also be used for the exhaust pipe mechanism of a small vertical take-off and landing aircraft that gathers by extending ducts.

  As mentioned above, although preferred embodiment of this invention was described, the exhaust pipe mechanism used for the turbine engine which concerns on this invention can include these combinations as much as possible not only in these. Moreover, although the present Example demonstrated the case where it used for a small vertical take-off and landing aircraft, it can be used also for an aircraft etc. which use a turbine engine, for example, it is ducted by using the exhaust pipe mechanism used for the turbine engine which concerns on this invention. It is possible to effectively lower the temperature of the exhaust gas discharged from the exhaust gas.

FIG. 1 is a perspective view showing a schematic configuration of a small vertical take-off and landing aircraft. 2A is a side sectional view showing a configuration of an exhaust pipe mechanism used in the turbine engine according to the present embodiment, and FIG. 2B is a sectional view seen from the duct outlet side. 3, (a) is a cross-sectional view of a side view viewed from the right side of FIG. 2 showing the configuration of the exhaust pipe mechanism used in the turbine engine according to the present embodiment, and (b) is a cross-sectional view of (a). It is sectional drawing seen from the discharge port side of the duct. FIG. 4 is a side view corresponding to FIG. 5 is a cross-sectional view taken along the line AA in FIG. FIG. 6 is a cross-sectional view of a conventionally used duct opening. FIG. 7 is a diagram showing the mixing effect in the conventional example. FIG. 8 is a diagram illustrating the mixing effect according to the present embodiment. FIG. 9 is a table showing the relationship between the temperature drop in the vicinity of the duct outlet and the distance from the vicinity of the duct outlet in comparison between the present embodiment and the conventional example. FIG. 10 is a side cross-sectional view showing the configuration when the exhaust pipe mechanism used in the turbine engine according to this embodiment is used in a turbofan engine. FIG. 11 is a diagram illustrating an example of a cross section of the opening of the first duct. FIG. 12 is a front view of a small vertical take-off and landing aircraft that gathers thrust generated by two engines by extending ducts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Compressor 2 ... Outside air intake 3 ... Combustion chamber 4, 5 ... Turbine 6 ... Fan 10 ... Turbine engine main body 20 ... Turbofan engine main body 30 ... First duct 30a ... Opening portion 30b of the first duct ... Central portion 30c of the first duct ... Upper end portion 31 of the first duct ... Collecting pipe 31a ... of the collecting pipe Opening 40 ... second duct 40a ... second duct opening 40b ... bending part 40c ... outside air inflow part 100 ... turbine engine 101 ... turbofan engine 200 ...・ Airframe 300 ... Pilot

Claims (5)

A first duct through which the exhaust discharged from the turbine engine flows;
An exhaust pipe mechanism comprising: a second duct arranged so as to form a double pipe around the first duct and through which the outside air around the turbine engine flows.
The opening for discharging the exhaust of the first duct and the opening for discharging the outside air around the turbine engine of the second duct are arranged so as to form a double pipe at substantially the same position in the longitudinal direction,
An exhaust pipe mechanism used for a turbine engine, wherein a cross section of an opening of the first duct is represented by a region defined by a width of a predetermined length or less with a predetermined center line as a reference. The turbine engine includes a fan for flowing outside air around the turbine engine,
The part of the outside air around the turbine engine that flows in by the fan flows into the turbine engine, and the outside air around the other turbine engines flows into the second duct. An exhaust pipe mechanism used for the turbine engine described.   The opening for discharging the outside air around the turbine engine of the second duct extends beyond the opening for discharging the exhaust of the first duct, and is bent toward the turbine engine side. An exhaust pipe mechanism used for a turbine engine according to claim 1 or 2.   4. The turbine according to claim 1, wherein a cross section of the opening of the first duct has a shape in which a plurality of the predetermined center lines extend radially with reference to a coupling point. 5. Exhaust pipe mechanism used for engines.   The exhaust pipe mechanism used for a turbine engine according to any one of claims 1 to 3, wherein a cross section of the opening of the first duct has an elliptical shape.

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