JP2020159275A - Turbine stator blade and turbine - Google Patents

Abstract

To provide a turbine stator blade whose efficiency is further improved by suppressing a secondary flow, and a turbine.SOLUTION: A turbine stator blade is provided in a flow path of a fluid flowing along an axis, and has a blade body having an airfoil section which extends in the radial direction of the axis and in which a front S1 becoming a high-pressure side when viewed from the radial direction and a back S2 becoming a low-pressure side are formed. The blade body has a chip side portion 31A located on the outermost side in the radial direction, a central portion 31B provided inside in the radial direction of the chip side portion 31A, and a hub side portion 31C provided further inside in the radial direction of the central portion 31B. In at least one of the chip side portion 31A and the hub side portion 31C, the turbine stator blade is twisted with respect to a reference airfoil Wc which is the airfoil in the central portion 31B, such that the leading edge 6d, which is the upstream edge, is located on the front S1 side in a direction Dc orthogonal to the chord of the reference airfoil Wc, and the trailing edge 7d, which is the downstream edge, is located on the back S2 side in the direction Dc orthogonal to the chord.SELECTED DRAWING: Figure 3

Description

The present invention relates to turbine vanes and turbines.

The gas turbine includes a compressor, a combustor, and a turbine. The compressor compresses the outside air to produce high pressure air. The combustor produces high-temperature and high-pressure combustion gas by mixing fuel with this high-pressure air and burning it. The turbine is rotationally driven by this combustion gas. The rotational force of the turbine is taken out from the shaft end and used for various purposes.

The turbine includes a rotating shaft that rotates around the axis, a turbine moving blade stage that is arranged along the axis direction on the rotating shaft, a casing that covers the rotating shaft and the turbine moving blade stage from the outside, and an inner peripheral surface of the casing. It has the above-mentioned turbine moving blade stage and a turbine stationary blade stage alternately arranged in the axial direction.

The turbine vane stage has a plurality of turbine vanes arranged in the circumferential direction with respect to the axis. Each turbine vane extends radially with respect to the axis. The fluid (combustion gas) flowing from one side in the axial direction collides with these turbine blades, changes the direction of flow, and is guided to the subsequent turbine blade stage. Here, in the turbine stationary blade, of the extending length in the radial direction, the portion on the chip side (outer in the radial direction) and the portion on the hub side (inner in the radial direction) are at the center excluding the tip side and the hub side. It is known that a flow component called a secondary flow is more likely to occur than a part. The secondary flow is a flow that travels while turning from the front edge to the trailing edge of the turbine vane. When the secondary flow is dominant, the energy loss of the mainstream flowing along the turbine vane increases. As a result, the efficiency of the turbine can be reduced.

Therefore, for example, the configuration described in Patent Document 1 below has been proposed. In the turbine stationary blade (nozzle blade) described in Patent Document 1, the throat pitch ratio is expanded at the central portion in the blade height direction by bending the trailing edge of the blade in the circumferential direction. As a result, the flow is concentrated in the central part, and the secondary flow is suppressed.

Japanese Patent No. 4723043

However, in the turbine vane described in Patent Document 1, since the trailing edge having a relatively large flow velocity is curved, the friction loss between the fluid and the turbine vane increases. As a result, the effect of suppressing the secondary flow may be offset by friction loss, limiting the efficiency improvement of the turbine.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a turbine stationary blade and a turbine whose efficiency is further improved by suppressing a secondary flow.

The turbine airfoil according to one aspect of the present invention is a turbine airfoil provided in a flow path of a fluid flowing along an axis, and extends in the radial direction of the axis and has a ventral surface on the high pressure side when viewed from the radial direction. And has an airfoil body having an airfoil cross section with a back surface formed on the low pressure side, and the airfoil body is provided on the chip side portion located on the outermost radial side and on the radial inner side of the chip side portion. It has a central portion and a hub side portion provided on the inner side in the radial direction of the central portion, and at least one of the chip side portion and the hub side portion is an airfoil in the central portion. For a reference airfoil, the front edge, which is the upstream edge, is located on the ventral side in the direction orthogonal to the airfoil chord, and the trailing edge, which is the downstream edge, is orthogonal to the chord. It is twisted so that it is located on the back side in the direction of

According to the above configuration, at least one of the tip side portion and the hub side portion is the ventral side in the direction in which the front edge is orthogonal to the chord of the reference airfoil with respect to the reference airfoil which is the airfoil in the central portion. It is twisted so that the trailing edge is located on the back side in the direction orthogonal to the chord. As a result, in the chip side portion and the hub side portion, the portion having the lowest pressure (static pressure) in the entire area in the axial direction is shifted from the trailing edge side to the front edge side. As a result, a pressure gradient is formed from the central portion to the chip side or the hub side from the front edge to the trailing edge. This pressure gradient allows the secondary flow to be pressed against the chip side or hub side. That is, the loss due to the growth of the secondary flow can be reduced.

In the turbine stationary blade, the amount of twist with respect to the reference airfoil may be smaller at the trailing edge of at least one of the tip side portion and the hub side portion than the front edge.

According to the above configuration, the wet area on the trailing edge side can be reduced by reducing the twist amount of the trailing edge as compared with the leading edge. By reducing the wet area, friction loss of the fluid passing through the trailing edge can be suppressed. Here, since the flow velocity is high on the trailing edge side, friction loss is likely to occur when the wet area increases. However, according to the above configuration, since the wet area is suppressed, such friction loss can be effectively reduced.

In the turbine stationary blade, when viewed from the circumferential direction with respect to the axis line, the front edge may form a linear shape extending in the radial direction at the central portion.

According to the above configuration, at the central portion of the turbine vane, the front edge forms a linear shape extending in the radial direction. Thereby, for example, the increase in the wet area can be suppressed as compared with the case where the entire front edge is curved instead of straight. As a result, an increase in friction loss can be suppressed.

In the turbine stationary blade, when viewed from the axial direction, the front edge of the tip side portion may be inclined and extended toward the ventral surface side toward the outer side in the radial direction.

According to the above configuration, at the chip side portion, the front edge is inclined toward the ventral surface side toward the outer side in the radial direction. As a result, in the chip side portion, the portion having the lowest pressure (static pressure) in the entire area in the axial direction shifts from the trailing edge side (downstream side) to the front edge side. As a result, a pressure gradient is formed from the central portion to the side portion of the chip toward the position where the static pressure becomes the smallest from the front edge. This pressure gradient allows the secondary flow to be pressed against the side of the chip. That is, the loss due to the growth of the secondary flow can be reduced.

In the turbine stationary blade, when viewed from the axial direction, the front edge of the hub side portion may be inclined and extended toward the ventral surface side toward the inner side in the radial direction.

According to the above configuration, on the hub side, the front edge is inclined toward the ventral surface side toward the inner side in the radial direction. As a result, in the hub side portion, the portion having the lowest pressure (static pressure) in the entire area in the axial direction is shifted from the trailing edge side (downstream side) to the front edge side (upstream side). As a result, a pressure gradient is formed from the central portion to the hub side portion from the front edge toward the position where the static pressure becomes the smallest. This pressure gradient allows the secondary flow to be pressed against the hub side. That is, the loss due to the growth of the secondary flow can be reduced.

In the turbine stationary blade, when viewed from the axial direction, the trailing edge of the tip side portion may be inclined and extended toward the back surface side toward the outer side in the radial direction.

According to the above configuration, at the chip side portion, the trailing edge is inclined toward the back surface side toward the outer side in the radial direction. As a result, in the chip side portion, the portion where the pressure (static pressure) is the lowest in the entire area in the axial direction is shifted from the trailing edge side to the front edge side (upstream side). As a result, a pressure gradient is formed from the central portion to the side portion of the chip toward the position where the static pressure becomes the smallest from the front edge. This pressure gradient allows the secondary flow to be pressed against the side of the chip. That is, the loss due to the growth of the secondary flow can be reduced.

In the turbine stationary blade, when viewed from the axial direction, the trailing edge of the hub side portion may be inclined and extended toward the back surface side toward the inner side in the radial direction.

According to the above configuration, on the hub side, the trailing edge is inclined toward the back side toward the outer side in the radial direction. As a result, in the hub side portion, the portion where the pressure (static pressure) is the lowest in the entire area in the axial direction is shifted from the trailing edge side to the front edge side (upstream side). As a result, a pressure gradient is formed from the central portion to the hub side portion from the front edge toward the position where the static pressure becomes the smallest. This pressure gradient allows the secondary flow to be pressed against the hub side. That is, the loss due to the growth of the secondary flow can be reduced.

In the turbine stationary blade, when viewed from the circumferential direction with respect to the axis line, the front edge of the tip side portion may extend toward the upstream side in the radial direction outward.

In the turbine stationary blade, the front edge of the hub side portion may extend toward the upstream side in the radial direction when viewed from the circumferential direction with respect to the axis line.

In the turbine vane, the trailing edge of the tip side portion may extend toward the downstream side in the radial direction when viewed from the circumferential direction with respect to the axis.

In the turbine stationary blade, the trailing edge of the hub side portion may extend toward the downstream side inward in the radial direction when viewed from the circumferential direction with respect to the axis line.

The turbine according to one aspect of the present invention includes a rotating shaft extending along an axis, a plurality of turbine blade stages arranged at intervals in the axial direction on the rotating shaft, and the turbine blade stage in the axial direction. A plurality of turbine blade stages having a plurality of turbine blades according to any one of the above aspects arranged alternately with the above.

According to the above configuration, it is possible to provide a turbine that can be operated more efficiently by suppressing the formation of a secondary flow in the turbine stationary blade.

According to the present invention, it is possible to provide a turbine stationary blade and a turbine having further improved efficiency by suppressing a secondary flow.

It is a schematic diagram which shows the structure of the turbine which concerns on embodiment of this invention. It is a figure which looked at the turbine stationary blade which concerns on embodiment of this invention from the circumferential direction with respect to the axis. It is a figure which looked at the turbine stationary blade which concerns on embodiment of this invention from the radial direction with respect to the axis. It is a perspective view which shows the structure of the turbine stationary blade which concerns on embodiment of this invention. It is a figure which shows the pressure distribution (isobar) on the back surface side of the turbine stationary blade which concerns on embodiment of this invention. It is a graph which shows the static pressure distribution in the chord direction of the turbine stationary blade which concerns on embodiment of this invention. It is a figure which looked at the turbine stationary blade which concerns on the modification of embodiment of this invention from the circumferential direction with respect to the axis. It is a figure which shows the further modification of the turbine stationary blade which concerns on embodiment of this invention, and is the figure which looked at the turbine stationary blade from the circumferential direction with respect to the axis. It is sectional drawing which shows the structure of the turbine stationary blade which concerns on the modification of the Embodiment of this invention.

The first embodiment of the present invention will be described with reference to FIGS. 1 to 6. The turbine 100 according to the present embodiment is suitably used for a turboshaft engine mounted on a helicopter. Although not shown in detail, the turboshaft engine includes a compressor that compresses external air to generate high-pressure air and a combustor that produces high-temperature and high-pressure combustion gas by mixing fuel with high-pressure air and burning it. It includes a turbine 100 that is rotationally driven by combustion gas, and a rotor that coaxially connects the compressor and the turbine 100. The rotational force of the rotor is taken out to the outside via a transmission or the like, and in the case of a helicopter, it is used to rotate the main rotor and tail rotor.

Next, the configuration of the turbine 100 will be described. As shown in FIG. 1, the turbine 100 has a rotary shaft 1, a turbine blade stage 2, and a turbine stationary blade stage 3. The rotating shaft 1 has a columnar shape extending along the axis Ac. A plurality (two) of turbine blade stages 2 are provided on the outer peripheral surface of the rotating shaft 1 at intervals in the axis Ac direction. Each turbine blade stage 2 has a plurality of turbine blades 20 arranged in the circumferential direction with respect to the axis Ac. The turbine rotor blade 20 has a rotor blade body 21 having an airfoil cross section and a platform 22 provided on the radial inside of the rotor blade body 21. Further, the dividing ring 4 faces the radial outer end of the rotor blade body 21.

The turbine blade stages 3 are arranged alternately with the turbine blade stages 2 in the axial direction Ac. Specifically, each turbine blade stage 3 is arranged on the downstream side of each turbine blade stage 2. The turbine stationary blade stage 3 has a plurality of turbine stationary blades 30 arranged in the circumferential direction with respect to the axis line Ac. Each turbine vane 30 is provided at a vane body 31 (blade body) having an airfoil cross section, a tip shroud 32 provided at the radial outer end of the airfoil body 31, and a radial inner end. It has a hub shroud 33 and. Although not shown in detail, the tip shroud 32 is fixed to the inner peripheral surface of the casing.

The tail cover 5 of the combustor is connected to the upstream side of the turbine 100. The combustion gas flowing through the tail cover 5 is rectified when passing through the turbine blade stage 3 and collides with the turbine blade stage 2. As a result, a rotational force is applied to the rotating shaft 1.

Next, the configuration of the turbine stationary blade 30 will be described with reference to FIGS. 2 to 4. FIG. 2 is a view of the turbine stationary blade 30 as viewed from the axis O direction. As shown in FIG. 2, the turbine stationary blade 30 has the above-mentioned tip shroud 32, a stationary blade main body 31, and a hub shroud 33 from the outer side to the inner side in the radial direction. The stationary blade main body 31 has a tip side portion 31A, a central portion 31B, and a hub side portion 31C from the outer side to the inner side in the radial direction. The radial outer end of the tip side portion 31A is connected to the tip shroud 32. The radial inner shroud on the chip side is integrally connected to the radial outer end of the central portion 31B. The radial outer end of the hub side 31C is integrally connected to the radial inner end of the central 31B. The radial inner end of the hub side portion 31C is connected to the hub shroud 33.

As shown in FIG. 3, the chip side portion 31A, the central portion 31B, and the hub side portion 31C all have a blade-shaped cross-sectional shape. More specifically, this airfoil has an ventral surface S1 on the high pressure side and a back surface S2 on the low pressure side when viewed in the radial direction. The ventral surface S1 is recessed toward the downstream side. The back surface S2 bulges toward the downstream side. Of the connecting portions of the ventral surface S1 and the back surface S2, the edge facing the upstream side is the front edge 6, and the edge facing the downstream side is the trailing edge 7. The end portion including the front edge 6 has a smooth curved surface shape from the ventral surface S1 side to the back surface S2 side. At the end including the trailing edge 7, the ventral surface S1 and the back surface S2 intersect at an acute angle.

In FIG. 3, the solid line shows the airfoil cross section of the tip side portion 31A and the hub side portion 31C, and the chain line shows the airfoil cross section of the central portion 31B. Here, the airfoil of the central portion 31B is referred to as a reference airfoil Wc. Further, the straight line connecting the front edge 6c and the trailing edge 7c of the reference airfoil Wc is called the reference chord line Ch, and the direction orthogonal to the reference chord line Ch is called the orthogonal direction Dc. In this case, as shown in FIG. 3, in the tip side portion 31A and the hub side portion 31C, the front edge 6d is located on the ventral surface S1 side in the orthogonal direction Dc with respect to the reference airfoil Wc. On the other hand, the trailing edge 7d is located on the back surface S2 side in the orthogonal direction Dc with respect to the reference airfoil Wc. That is, the airfoils of the tip side portion 31A and the hub side portion 31C are twisted counterclockwise with respect to the reference airfoil Wc when viewed from the outside in the radial direction. Further, in the tip side portion 31A and the hub side portion 31C, the amount of twist with respect to the reference airfoil Wc is relatively large on the front edge 6d side and relatively small on the trailing edge 7d side. The amount of twist in the tip side portion 31A and the hub side portion 31C is the same as each other. In the hub side portion 31C, it is desirable that the front edge 6d and the trailing edge 7c are twisted in a region where the radial height of the stationary blade body 31 is about 5% to 30% or less, and the tip side portion 31C. In 31A, it is desirable that the twist is formed in a region of about 70 to 95% or more of the radial height.

As a result, when viewed from the axis O direction, as shown in FIG. 2, in the chip side portion 31A and the hub side portion 31C, the front edge 6d and the trailing edge 7d extend obliquely toward the downstream side. Specifically, in the chip side portion 31A, the front edge 6d and the trailing edge 7d are inclined toward the downstream side from the inside to the outside in the radial direction. In the hub side portion 31C, the front edge 6d and the trailing edge 7d are inclined toward the downstream side from the outer side to the inner side in the radial direction. On the other hand, the front edge 6c and the trailing edge 7c of the central portion 31B extend linearly in the radial direction. With such a configuration, when the turbine stationary blade 30 is viewed from an oblique direction, it has a shape as shown in FIG.

When the turbine stationary blade is viewed from the ventral side (ventral side in the circumferential direction) (when viewed from the lower side in FIG. 3), the front edge 6d of the tip side portion 31A moves toward the upstream side in the radial direction. It extends toward. Further, in the hub side portion 31C, the front edge 6d extends toward the upstream side toward the inner side in the radial direction. Further, in the chip side portion 31A, the trailing edge 7d extends toward the downstream side toward the outer side in the radial direction. Further, in the hub side portion 31C, the trailing edge 7d extends toward the downstream side toward the inner side in the radial direction.

Subsequently, the behavior of the turbine stationary blade 30 according to the present embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 shows the static pressure distribution (isobars) of the fluid on the back surface S2 of the turbine stationary blade 30, with the left side of the drawing as the front edge 6 side and the right side as the trailing edge 7 side. The upper part of the drawing is the chip side portion 31A, and the lower part is the hub side portion 31C. As shown in the figure, a pressure gradient is formed on the back surface S2 so that the static pressure gradually decreases from the front edge 6 side to the trailing edge 7 side (chain line arrow in FIG. 5). Further, in the vicinity of the chip side portion 31A and the vicinity of the hub side portion 31C, the intervals between the isobars are narrowed, and the ends of the isobars are located on the front edge 6 side as compared with the central portion 31B. That is, as shown in FIG. 6, in the chord line direction, the position P1 where the static pressure is the smallest at the tip side portion 31A and the hub side portion 31C is before the position P2 where the static pressure is the smallest at the central portion 31B. It will be located on the edge 6 side.

Here, in the turbine stationary blade 30, among the extending lengths in the radial direction, the tip side portion 31A and the hub side portion 31C are more likely to generate a flow component called a secondary flow than the central portion 31B. It has been known. The secondary flow is a flow that proceeds while turning from the front edge 6 of the turbine vane 30 toward the trailing edge 7. If the secondary flow is predominant, the energy loss of the mainstream flowing along the turbine stationary blade 30 will increase. As a result, the efficiency of the turbine 100 may decrease.

However, according to the above configuration, at least one of the chip side portion 31A and the hub side portion 31C has a blade whose front edge 6d is the reference airfoil Wc with respect to the reference airfoil Wc which is the airfoil in the central portion 31B. It is twisted so that it is located on the ventral surface S1 side in the direction orthogonal to the chord and the trailing edge 7d is located on the back surface S2 side in the direction orthogonal to the chord. As a result, in the chip side portion 31A and the hub side portion 31C, the portion having the lowest pressure (static pressure) in the entire area in the axial direction Ac is shifted from the trailing edge 7d side to the front edge 6d side. As a result, a pressure gradient is formed from the central portion 31B toward the chip side portion 31A or the hub side portion 31C toward the position P1 where the pressure (static pressure) becomes the smallest from the front edge 6d. Due to this pressure gradient, the secondary flow can be pressed against the tip side portion 31A or the hub side portion 31C. That is, the loss due to the growth of the secondary flow can be reduced. As a result, the efficiency of the turbine 100 can be improved.

Further, according to the above configuration, in the chip side portion 31A and the hub side portion 31B, the wetting area on the trailing edge 7d side can be reduced by reducing the twist amount of the trailing edge 7d as compared with the front edge 6d. it can. By reducing the wet area, the friction loss of the fluid passing through the trailing edge 7d can be suppressed. Here, since the flow velocity on the trailing edge 7d side is higher than that on the front edge 6d side, friction loss is likely to occur when the wet area increases. However, according to the above configuration, since the wet area is suppressed, such friction loss can be effectively reduced.

In addition, according to the above configuration, in the central portion 31B of the turbine stationary blade 30, the front edge 6c has a linear shape extending in the radial direction. Thereby, for example, an increase in the wet area can be suppressed as compared with the case where the entire front edge 6 is curved instead of straight. As a result, an increase in friction loss can be suppressed.

Further, according to the above configuration, in the chip side portion 31A, the front edge 6d is inclined toward the ventral surface S1 side and the trailing edge 7d is inclined toward the back surface S2 side toward the outer side in the radial direction. .. As a result, in the chip side portion 31A, the portion where the pressure (static pressure) is the lowest in the entire area in the axial direction Ac direction is shifted from the trailing edge 7d side to the front edge 6d side. As a result, a pressure gradient is formed from the front edge 6d toward the position P1 where the static pressure is the smallest, from the central portion 31B toward the chip side portion 31A. Due to this pressure gradient, the secondary flow can be pressed against the chip side portion 31A. That is, the loss due to the growth of the secondary flow can be reduced.

Further, according to the above configuration, in the hub side portion 31C, the front edge 6d is inclined toward the ventral surface S1 side and the rear edge 7d is inclined toward the back surface S2 side toward the inner side in the radial direction. As a result, in the hub side portion 31C, the portion where the pressure (static pressure) is the lowest in the entire area in the axial direction Ac direction is shifted to the front edge 6d side. As a result, a pressure gradient is formed from the front edge 6d toward the position P1 where the static pressure is the smallest, from the central portion 31B toward the hub side portion 31C. Due to this pressure gradient, the secondary flow can be pressed against the hub side portion 31C. That is, the loss due to the growth of the secondary flow can be reduced.

The embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above configuration as long as the gist of the present invention is not deviated. For example, in the above embodiment, an example in which the tip side portion 31A and the hub side portion 31C both form a twist with respect to the reference airfoil Wc has been described. However, as shown in FIG. 7 or 8, it is also possible to adopt a configuration in which a twist is formed in only one of the chip side portion 31A and the hub side portion 31C. In this case, as shown in FIG. 9, when adopting a configuration in which the insert member 90 for forming the cooling flow path is provided inside the turbine stationary blade 30, the insert member is from the end where the twist is not formed. The 90 can be easily inserted.

Further, in the above embodiment, an example in which the turbine vane 30 is applied to the turboshaft engine mounted on the helicopter has been described. However, the application target of the turbine stationary blade 30 is not limited to the turboshaft engine. As another application example, the above turbine vane 30 is applied to any engine that requires a reduced number of blade rows and a high load / low aspect ratio blade in order to simplify the structure and reduce the cost. It is possible. More specifically, the above-mentioned turbine stationary blade 30 can be suitably used for an aircraft engine such as a vertical take-off and landing aircraft, a flying object, and a drone. The above-mentioned aspect ratio refers to the ratio of the blade height to the cord length of the blade. The cord length is the length of a line segment connecting the front edge 6 and the trailing edge 7. For example, when this aspect ratio is 1 or less, it can be said that the aspect ratio is low.

100 ... Turbine 1 ... Rotating shaft 2 ... Turbine blade stage 3 ... Turbine blade stage 4 ... Dividing ring 5 ... Tail cylinder 6, 6c, 6d ... Front edge 7, 7c, 7d ... Trailing edge 20 ... Turbine blade 21 ... Moving blade body 22 ... Platform 30 ... Turbine stationary blade 31 ... Static blade body 32 ... Chip shroud 33 ... Hub shroud 31A ... Chip side 31B ... Central 31C ... Hub side Ac ... Axis Ch ... Reference chord line Dc ... Orthogonal Direction S1 ... Abdominal surface S2 ... Back surface Wc ... Reference wing type

Claims (12)

A turbine vane provided in the flow path of fluid flowing along the axis.
It has a wing body that extends in the radial direction of the axis and has an airfoil-shaped cross section in which a ventral surface on the high pressure side and a back surface on the low pressure side when viewed from the radial direction are formed.
The wing body
The chip side located on the outermost radial direction and
A central portion provided on the inner side in the radial direction of the chip side portion, and a central portion.
A hub side portion provided on the inner side in the radial direction of the central portion, and
Have,
At least one of the tip side portion and the hub side portion has a front edge, which is an upstream end edge, orthogonal to the chord of the reference airfoil with respect to the reference airfoil, which is the airfoil in the central portion. A turbine airfoil that is located on the ventral side in the direction of airfoil and is twisted so that the trailing edge, which is the edge on the downstream side, is located on the back side in the direction orthogonal to the chord. The turbine stationary blade according to claim 1, wherein the amount of twist with respect to the reference airfoil is smaller at the trailing edge of at least one of the tip side portion and the hub side portion than the front edge. The turbine stationary blade according to claim 1 or 2, wherein the front edge extends in the radial direction at the central portion when viewed from the circumferential direction with respect to the axis. The turbine stationary blade according to any one of claims 1 to 3, wherein the front edge of the tip side portion is inclined toward the ventral surface side toward the outer side in the radial direction when viewed from the axial direction. .. The turbine stationary blade according to any one of claims 1 to 4, wherein the front edge of the hub side portion is inclined and extends toward the ventral surface side toward the inside in the radial direction when viewed from the axial direction. .. The turbine stationary blade according to any one of claims 1 to 5, wherein when viewed from the axial direction, the trailing edge of the tip side portion is inclined and extends toward the back surface side toward the outer side in the radial direction. .. The turbine stationary blade according to any one of claims 1 to 6, wherein when viewed from the axial direction, the trailing edge of the hub side portion is inclined toward the back surface side toward the inside in the radial direction. .. The turbine stationary blade according to any one of claims 1 to 7, wherein the front edge of the tip side portion extends toward the upstream side as it goes outward in the radial direction when viewed from the circumferential direction with respect to the axis line. The turbine stationary blade according to any one of claims 1 to 8, wherein the front edge of the hub side portion extends inward in the radial direction toward the upstream side when viewed from the circumferential direction with respect to the axis. The turbine stationary blade according to any one of claims 1 to 9, wherein the trailing edge of the tip side portion extends toward the downstream side as it goes outward in the radial direction when viewed from the circumferential direction with respect to the axis. The turbine stationary blade according to any one of claims 1 to 10, wherein in the hub side portion when viewed from the circumferential direction with respect to the axis line, the trailing edge extends toward the downstream side toward the inner side in the radial direction. A rotation axis that extends along the axis and
A plurality of turbine blade stages arranged at intervals in the axial direction on the rotation axis,
A plurality of turbine blade stages having a plurality of turbine blades according to any one of claims 1 to 11 arranged alternately with the turbine blade stages in the axial direction.
A turbine equipped with.

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