JP2019120169A - Rotary machine - Google Patents

Abstract

To provide a rotary machine capable of further suppressing fluttering.SOLUTION: A rotary machine comprises a plurality of blades extending radially and provided at intervals in a circumferential direction. The blade has a belly side surface formed into a concave surface shape and a back side surface formed into a convex surface shape in a cross-sectional view in a radial direction. A position that is a part of the back side surface and at which a flow passage cross sectional area is minimum in a flow passage formed by the belly side surface and the back side surface of the blades adjacent to each other is defined as a primary throat. At a portion corresponding to the primary throat position on the back side surface, a flow disturbance part is provided for disturbing a flow along the back side surface.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotating machine.

  The steam turbine includes a rotor rotating about an axis, a plurality of moving blades attached to the rotor, a casing that covers the rotor and the moving blades from the outside, and a plurality of stationary blades attached to the inner surface of the casing. There is. The high temperature and high pressure steam flows in from one side in the axial direction, energy is added to the moving blades, and the rotating shaft rotates. A generator connected to the steam turbine is driven by the rotational energy.

  The plurality of moving blades are attached radially around the axis on the outer peripheral surface of the rotor. Each moving blade has a wing-shaped cross-sectional shape as viewed in the radial direction with respect to the axis. Specifically, the moving blade has a belly surface having a concave surface shape as viewed from the radial direction and a rear surface having a convex surface shape (see, for example, Patent Document 1 below). In recent years, there is a concern that flutter may occur due to the increase in blade diameter, reduction in weight, increase in flow rate for high output, application of a composite material, or the like. As a method for suppressing flutter, there is known a method in which a sliding portion is provided on a stub or a shroud to increase rigidity by increasing structural damping or thickening of a blade, and increase non-dimensional frequency to achieve stabilization. .

Unexamined-Japanese-Patent No. 2004-340131

  However, the main measures for suppressing flutter so far are mainly the improvement of blade size (blade thickness increase and the like) and the addition of structural damping due to stubs and the like, and no improvement measures for flow fields have been proposed.

  The present invention was made in order to solve the above-mentioned subject, and an object of the present invention is to provide a rotating machine which can further control flutter.

  According to the first aspect of the present invention, the rotary machine includes a plurality of wings extending in the radial direction and provided at intervals in the circumferential direction, and the wings have a concave curved shape in a cross sectional view in the radial direction. The flow passage cross-sectional area of the flow passage formed by the flanks and the back side of the wings which are adjacent to each other and which are a part of the back side and have a ventral side and a convexly curved back side. The position where the value of d becomes small is taken as the primary throat position, and a portion of the back surface corresponding to the primary throat position is provided with a flow disturbance portion that disturbs the flow along the back surface.

  According to this configuration, the velocity distribution of the flow is disturbed in the region downstream of the flow disturbing portion. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). That is, in the region where the flow is decelerated if there is no flow disturbing portion, the flow is disturbed by the flow disturbing portion, whereby the periodic destabilizing force acting on the moving blade can be reduced. This can reduce the possibility of fluttering on the blades.

  Further, according to the second aspect of the present invention, the flow disturbing portion is a protrusion that protrudes from the back surface toward the ventral surface side, and when viewed from the radial direction, the protrusion has an arc-shaped cross section. It may be done.

  According to this configuration, the collision of the flow with the projection causes disturbance in the flow velocity distribution. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering on the blades.

  Further, according to the third aspect of the present invention, the flow disturbing portion may be a groove which is formed so as to be recessed from the back side surface and which extends in the radial direction.

  According to this configuration, a partial component of the flow enters the groove to cause disturbance in the flow velocity distribution. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering on the blades.

  Further, according to the fourth aspect of the present invention, the flow disturbing portion may be a rough surface whose roughness is higher than that of the other region on the back side.

  According to this configuration, friction in passing through the rough surface causes disturbance in the velocity distribution of the flow. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering on the blades.

  Further, according to the fifth aspect of the present invention, the flow disturbing portion may be a plurality of dimples formed to be recessed from the back surface.

  According to this configuration, a partial component of the flow enters the dimple to cause disturbance in the flow velocity distribution. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering on the blades.

  Further, according to the sixth aspect of the present invention, the flow disturbing portion may be within ± 20% of the cord length of the wing based on the first throat position.

  Here, it is known that the area where the flow velocity decreases (the area where the decelerating flow occurs) is within ± 20% of the chord length of the wing, based on the primary throat position. That is, in this region, aerodynamic negative damping tends to increase. However, according to the above configuration, by providing the flow disturbance portion in the area where the decelerating flow occurs, flutter can be suppressed more effectively.

  Further, according to the seventh aspect of the present invention, the flow disturbance portion is provided only in a region of 50% or less of the radial length of the wing from the radial outer end portion of the wing. May be

  Here, it is known that the area where the flow velocity decreases (the area where the decelerating flow occurs) is an area from the radial outer end of the blade to 50% or less of the radial length of the blade. . That is, in this region, aerodynamic negative damping tends to increase. However, according to the above configuration, by providing the flow disturbance portion in the area where the decelerating flow occurs, flutter can be suppressed more effectively.

  According to the present invention, it is possible to provide a rotary machine capable of further suppressing flutter.

It is a schematic diagram which shows the structure of the rotary machine (steam turbine) which concerns on 1st embodiment of this invention. It is a sectional view which looked at a bucket concerning a first embodiment of the present invention from a diameter direction. It is the figure which looked at the moving blade which concerns on 1st embodiment of this invention from the direction which intersects radial direction. It is a graph which shows the characteristic of the moving blade which concerns on 1st embodiment of this invention, Comprising: (a) shows blade surface velocity distribution, (b) shows distribution of attenuation in a blade surface. It is sectional drawing which looked at the moving blade which concerns on the comparative example of 1st embodiment of this invention from radial direction. It is a graph which shows the characteristic of the moving blade which concerns on the comparative example of 1st embodiment of this invention, Comprising: (a) shows blade surface velocity distribution, (b) shows distribution of attenuation | damping in a blade surface. It is sectional drawing which looked at the moving blade which concerns on 2nd embodiment of this invention from radial direction. It is sectional drawing which looked at the moving blade which concerns on 3rd embodiment of this invention from radial direction. It is sectional drawing which looked at the moving blade which concerns on 4th embodiment of this invention from radial direction.

First Embodiment
A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the steam turbine 1 (rotary machine) includes a steam turbine rotor 3 extending along the direction of the axis O, a steam turbine casing 2 covering the steam turbine rotor 3 from the outer peripheral side, and a shaft of the steam turbine rotor 3 A journal bearing 4 rotatably supporting the end 11 about an axis O and a thrust bearing 5 are provided.

  The steam turbine rotor 3 has a plurality of moving blades 30. A plurality of moving blades 30 are arrayed at regular intervals in the circumferential direction of the steam turbine rotor 3. Also in the direction of the axis O, the rows of the plurality of moving blades 30 are arranged at constant intervals. The blade 30 has a blade body 31 and a blade shroud 34 (shroud). The wing body 31 protrudes radially outward from the outer peripheral surface of the steam turbine rotor 3. The wing body 31 has a wing-shaped cross section as viewed in the radial direction. A moving blade shroud 34 is provided at the tip end (radially outer end) of the wing body 31.

  The steam turbine casing 2 has a substantially cylindrical shape covering the steam turbine rotor 3 from the outer peripheral side. A steam supply pipe 12 for taking in steam is provided on one side in the direction of the axis O of the steam turbine casing 2. On the other side of the steam turbine casing 2 in the direction of the axis O, a steam discharge pipe 13 for discharging steam is provided. In the following description, the side where the steam supply pipe 12 is located as viewed from the steam discharge pipe 13 is referred to as the upstream side, and the side where the steam discharge pipe 13 is located as viewed from the steam supply pipe 12 is referred to as the downstream side.

  A plurality of stator blades 21 are provided along the inner circumferential surface 25 of the steam turbine casing 2. The stationary blade 21 is a blade-like member connected to the inner circumferential surface 25 of the steam turbine casing 2 via the stationary blade pedestal 24. Further, a vane shroud 22 is provided at a tip end (a radially inner end) of the vane 21. Similar to the moving blades 30, a plurality of the stationary blades 21 are arranged along the circumferential direction of the inner circumferential surface 25 and the direction of the axis O. The moving blade 30 is disposed to enter an area between the plurality of adjacent stationary blades 21.

  In the inside of the steam turbine casing 2, a region in which the stationary blades 21 and the moving blades 30 are arranged forms a main flow passage 20 through which the steam S, which is a working fluid, flows. Between the inner circumferential surface 25 of the steam turbine casing 2 and the blade shroud 34, a recess 50 that is recessed radially outward with respect to the axis O is formed over the entire circumferential direction.

  The steam S is supplied via the upstream steam supply pipe 12 to the steam turbine 1 configured as described above. Thereafter, as the steam turbine rotor 3 rotates, it passes through the row of the stationary blades 21 and the moving blades 30 and is eventually discharged toward the subsequent device (not shown) through the downstream steam discharge pipe 13.

  The journal bearing 4 supports a load in the radial direction with respect to the axis O. One journal bearing 4 is provided at each end of the steam turbine rotor 3. The thrust bearing 5 supports a load in the direction of the axis O. The thrust bearing 5 is provided only at the upstream end of the steam turbine rotor 3.

  Next, the configuration of the moving blade 30 will be described with reference to FIG. As shown to the same figure, the moving blade 30 which concerns on this embodiment has a wing-shaped cross section seeing from radial direction. Specifically, the moving blade 30 has a ventral side surface 30a in the form of a concave surface and a back surface 30b in the form of a convex surface. Furthermore, the thickness dimension of the moving blade 30 decreases from the leading edge 30L, which is the upstream end, toward the trailing edge 30T, which is the downstream end.

  The plurality of moving blades 30 are arranged at intervals in the circumferential direction with respect to the axis O. That is, the back side 30 b and the ventral side 30 a of the pair of moving blades 30, 30 adjacent to each other face each other in the circumferential direction. A space between the back surface 30 b and the ventral surface 30 a facing each other is an inter-blade flow path F. When the working fluid flows through the inter-blade flow path F, kinetic energy is added to the moving blades 30 by the flow colliding with the ventral surface 30a.

  Here, in the middle of the above-described inter-blade flow path F, the position at which the distance between the inner and outer surfaces 30a and 30b is the smallest when viewed from the radial direction is referred to as the primary throat position T1 (shown by a chain line in FIG. 2). . That is, at the primary throat position T1, the flow passage cross-sectional area of the inter-blade flow passage F is the smallest. On the back side 30b corresponding to the primary throat position T1, a protrusion 91 as a flow disturbing portion 90 is provided.

  The protrusion 91 is provided to disturb the flow along the back surface 30b. The protrusion 91 protrudes from the dorsal surface 30 b toward the ventral side. Seen from the radial direction, the projection 91 has an arc-shaped cross section. It is desirable that the projection 91 be within ± 20% of the cord length of the moving blade 30 on the back side surface 30b with reference to the primary throat position T1. It is further desirable that the projections 91 be within ± 10% of the cord length, and most preferably, the projections 91 be within ± 5% of the cord length. Here, the cord length refers to the length of a straight line connecting the front edge 30L and the rear edge 30T of the moving blade 30.

  The provision of the projection 91 changes the throat position (secondary throat position T2) of the moving blade 30 from the above-mentioned primary throat position T1. In the example of FIG. 2, the case where primary throat position T1 and secondary throat position T2 correspond is shown. When the projection 91 is within ± 20% of the cord length with respect to the primary throat position T1 and is provided at a position different from the primary throat position T1, the position at which the projection 91 is provided is It becomes the secondary throat position T2.

  Furthermore, as shown in FIG. 3, the protrusion 91 is provided in a region of 50% or less of the radial length of the moving blade 30 from the radially outer end portion 30R of the moving blade 30. That is, the projections 91 are provided only in the region of 50 to 100% Ht of the moving blade 30. In the case of a free standing wing not having a moving blade shroud, it is desirable that the projection 91 be provided only in the region of 80 to 100% Ht of the moving blade 30.

  Subsequently, an operation of the steam turbine 1 according to the present embodiment will be described. When operating the steam turbine 1, high temperature and high pressure steam is supplied from the external steam supply source (not shown) to the inside (main flow passage 20) of the steam turbine casing 2 through the steam supply pipe 12. The steam forms a flow (main steam) flowing from the upstream side to the downstream side along the main flow passage 20. The main steam alternately collides with the stationary blades 21 and the moving blades 30 to apply rotational force to the steam turbine rotor 3 via the moving blades 30. The rotation of the steam turbine rotor 3 is taken out from the shaft end to drive an external device such as a generator (not shown).

  When the steam turbine 1 is in operation, a flow of steam along the ventral surface 30a and a flow of steam along the back surface 30b occur around the moving blade 30. The vapor flows from one side to the other side in the circumferential direction from the upstream side to the downstream side on both the ventral surface 30a and the dorsal surface 30b. Here, as shown in FIG. 5 as a comparative example, in the case where no structure is provided on the back surface 30b, the flow along the back surface 30b causes a decrease in speed on the back surface 30b (deceleration A flow is formed). More specifically, the velocity distribution as shown in the graph of FIG. 6 (a) is exhibited. In the graph of FIG. 6 (a), the horizontal axis indicates the position from the leading edge 30L to the trailing edge 30T, and the vertical axis indicates the velocity. Further, the chain line indicates the velocity distribution on the dorsal surface 30b, and the solid line indicates the velocity distribution on the ventral surface 30a. As shown in the graph, in the back surface 30b, the velocity decreases in the region on the trailing edge 30T side of the position P (decelerating flow is generated).

  On the other hand, the graph of FIG. 6 (b) shows the distribution of damping force applied to the fluid in the moving blade 30. In the graph of FIG. 6B, the horizontal axis indicates the position from the leading edge 30L to the trailing edge 30T, and the vertical axis indicates the damping force. Further, the chain line indicates the damping force distribution on the dorsal surface 30b, and the solid line indicates the damping force distribution on the abdominal surface 30a. As shown in the graph, it can be seen that the damping force has a large negative value on the trailing edge 30T side of the position P where the decelerating flow occurs. This increase in negative damping can cause flutter on the blades 30.

  On the other hand, in the steam turbine 1 according to the present embodiment, the projections 91 (the flow disturbing portions 90) are provided on the back surface 30b of the moving blade 30. When the projections 91 are provided, the velocity distribution and the damping force distribution on the blade surface are in the states shown in FIGS. 4 (a) and 4 (b). As shown in FIG. 4 (a), it can be seen that in the region downstream of the position P where the decelerating flow occurs on the back surface 30b, the degree of deceleration is relaxed as compared with the case of FIG. 6 (a) . Furthermore, as shown in FIG. 4B, it can be seen that the decrease in damping force is smaller on the trailing edge 30T side than the position P where the decelerating flow occurs. That is, it can be seen that the increase in negative damping force is reduced as compared with the case of FIG. 6 (b). This is because, in the region where the flow is decelerated without the projection 91, the flow is disturbed by the projection 91, whereby the periodic destabilizing force acting on the moving blade can be reduced. Thereby, the occurrence of flutter in the moving blades 30 can be suppressed.

  As described above, in the steam turbine 1 according to the present embodiment, the velocity distribution of the flow is disturbed in the region downstream of the projection 91 as the flow disturbing portion 90. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering of the moving blades 30.

  Here, it is known that the area where the flow velocity decreases (the area where the decelerating flow occurs) is within ± 20% of the chord length of the wing with reference to the first throat position T1. That is, in this region, aerodynamic negative damping tends to increase. However, according to the above configuration, by providing the flow disturbance portion 90 in the area where the decelerating flow occurs, flutter can be suppressed more effectively.

  Furthermore, it is known that the area in which the flow velocity decreases (the area in which the decelerating flow occurs) is an area of 50% or less of the radial length of the wing from the radially outer end of the wing. That is, in this region, aerodynamic negative damping tends to increase. However, according to the above configuration, by providing the flow disturbance portion 90 in the area where the decelerating flow occurs, flutter can be suppressed more effectively.

  The first embodiment of the present invention has been described above. Note that various changes and modifications can be made to the above-described configuration without departing from the scope of the present invention. For example, in the first embodiment, the moving blade 30 of the steam turbine 1 has been described as an example. However, the application object of the present invention is not limited to the moving blades 30 of the steam turbine 1, and may be applied to a stationary blade. It is also possible to apply the invention to blades of axial compressors.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to the said 1st embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. As shown to the same figure, in this embodiment, the groove | channel 92 as the flow disturbance part 90 is formed on the back surface 30b of the moving blade 30. As shown in FIG. The groove 92 is recessed in a rectangular shape from the back surface 30 b toward the ventral surface 30 a as viewed in the radial direction. The groove 92 is preferably within ± 20% of the cord length of the moving blade 30 on the back surface 30b with reference to the primary throat position T1. The groove 92 is more preferably in the range of ± 10% of the cord length, and most preferably the groove 92 is in the range of ± 5% of the cord length. Here, the cord length refers to the length of a straight line connecting the front edge 30L and the rear edge 30T of the moving blade 30.

  Due to the formation of the groove 92, the throat position (secondary throat position T2) as the moving blade 30 changes from the above-mentioned primary throat position T1. In the example of FIG. 2, the case where primary throat position T1 and secondary throat position T2 correspond is shown.

  Furthermore, the groove 92 is provided in a region of 50% or less of the radial length of the moving blade 30 from the radially outer end of the moving blade 30. That is, the groove 92 is provided only in the region of 50 to 100% Ht of the moving blade 30. In the case of a free standing blade not having a moving blade shroud, it is desirable that the groove 92 be provided only in the region of 80 to 100% Ht of the moving blade 30.

  As described above, in the steam turbine 1 according to the present embodiment, the velocity distribution of the flow is disturbed in the region downstream of the groove 92 as the flow disturbing portion 90. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering of the moving blades 30.

  The second embodiment of the present invention has been described above. Note that various changes and modifications can be made to the above-described configuration without departing from the scope of the present invention. For example, in the second embodiment, the moving blade 30 of the steam turbine 1 has been described as an example. However, the application object of the present invention is not limited to the moving blades 30 of the steam turbine 1, and may be applied to a stationary blade. It is also possible to apply the invention to blades of axial compressors.

Third Embodiment
Subsequently, a third embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to said each embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. As shown in FIG. 8, in the present embodiment, a rough surface 93 as a flow disturbance portion 90 is formed on the back surface 30 b of the moving blade 30. The rough surface 93 is higher in roughness than the other regions on the dorsal surface 30b. As means for forming the rough surface 93, a method of applying a coating on the back surface 30b, a method of attaching carbon particles, and the like can be considered.

  It is desirable that the rough surface 93 be within ± 20% of the cord length of the moving blade 30 on the back surface 30b with reference to the primary throat position T1. The rough surface 93 is more preferably within ± 10% of the cord length, and most preferably the rough surface 93 is within ± 5% of the cord length. Here, the cord length refers to the length of a straight line connecting the front edge 30L and the rear edge 30T of the moving blade 30.

  Furthermore, the rough surface 93 is provided in a region of 50% or less of the radial length of the moving blade 30 from the radial outer end of the moving blade 30. That is, the rough surface 93 is provided only in the region of 50 to 100% Ht of the moving blade 30. In the case of a free standing wing not having a moving blade shroud, it is desirable that the rough surface 93 be provided only in the region of 80 to 100% Ht of the moving blade 30.

  As described above, in the steam turbine 1 according to the present embodiment, the rough surface 93 as the flow disturbing portion 90 is formed, whereby a frictional force is generated when passing through the rough surface 93, and The velocity distribution is disturbed. Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering of the moving blades 30.

  The third embodiment of the present invention has been described above. Note that various changes and modifications can be made to the above-described configuration without departing from the scope of the present invention. For example, in the third embodiment, the moving blade 30 of the steam turbine 1 has been described as an example. However, the application object of the present invention is not limited to the moving blades 30 of the steam turbine 1, and may be applied to a stationary blade. It is also possible to apply the invention to blades of axial compressors.

Fourth Embodiment
Subsequently, a fourth embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to said each embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. As shown in FIG. 9, in the present embodiment, a dimple area 94 as a flow disturbance portion 90 is formed on the back surface 30 b of the moving blade 30. The dimple area 94 has a plurality of dimples 95 formed on the back surface 30 b. Each dimple 95 is slightly recessed from the dorsal surface 30 b toward the ventral surface 30 a.

  The dimple area 94 is preferably within ± 20% of the cord length of the moving blade 30 on the back surface 30b with reference to the primary throat position T1. The dimple area 94 is more preferably within ± 10% of the cord length, and most preferably, the dimple area 94 is within ± 5% of the cord length. Here, the cord length refers to the length of a straight line connecting the front edge 30L and the rear edge 30T of the moving blade 30.

  Furthermore, the dimple region 94 is provided from the radial outer end of the moving blade 30 to a region of 50% or less of the radial length of the moving blade 30. That is, the dimple region 94 is provided only in the region of 50 to 100% Ht of the moving blade 30. In the case of a free standing blade not having a moving blade shroud, it is desirable that the dimple region 94 be provided only in the region of 80 to 100% Ht of the moving blade 30.

  As described above, in the steam turbine 1 according to the present embodiment, when the dimple region 94 as the flow disturbance portion 90 is formed, the velocity distribution of the flow is disturbed when passing through the dimple region 94. Produces Thereby, it can suppress that the aerodynamic damping in the said area becomes small too much (increase of aerodynamic negative damping). This can reduce the possibility of fluttering of the moving blades 30.

  The fourth embodiment of the present invention has been described above. Note that various changes and modifications can be made to the above-described configuration without departing from the scope of the present invention. For example, in the fourth embodiment, the moving blades 30 of the steam turbine 1 have been described as an example. However, the application object of the present invention is not limited to the moving blades 30 of the steam turbine 1, and may be applied to a stationary blade. It is also possible to apply the invention to blades of axial compressors.

DESCRIPTION OF SYMBOLS 1 ... steam turbine 2 ... steam turbine casing 3 ... steam turbine rotor 4 ... journal bearing 5 ... thrust bearing 11 ... shaft end 12 ... steam supply pipe 13 ... steam discharge pipe 20 ... main flow path 24 ... stator blade pedestal 25 ... inner peripheral surface 30: moving blade 30a: belly side 30b: back side 30L: leading edge 30T: trailing edge 31: wing main body 34: moving blade shroud 50: recessed portion 90: flow disturbing portion 91: projection 92: groove 93: rough surface 94: rough surface 94 Dimple area 95: Dimple F: Flow path between wings T1: Primary throat position T2: Secondary throat position

Claims (7)

A plurality of radially extending and circumferentially spaced apart vanes,
The wing has an anti-lateral side forming a concave surface and a back surface forming a convex surface in a cross-sectional view in the radial direction,
Of the channels formed by the ventral surface and the back surface of the wings that are part of the back surface, the position where the channel cross-sectional area is the smallest is taken as the primary throat position,
A rotating machine provided with a flow disturbing portion which disturbs the flow along the back side surface in a portion corresponding to the primary throat position in the back side surface.   The rotary machine according to claim 1, wherein the flow disturbing portion is a protrusion that protrudes from the back surface toward the abdominal surface side, and the protrusion has an arc-shaped cross section when viewed from the radial direction.   The rotary machine according to claim 1, wherein the flow disturbing portion is a groove which is formed to be recessed from the back surface and extends radially.   The rotary machine according to claim 1, wherein the flow disturbing portion is a rough surface having a roughness higher than that of the other region on the back surface.   The rotary machine according to claim 1, wherein the flow disturbing portion is a plurality of dimples formed to be recessed from the back surface.   The rotary machine according to any one of claims 1 to 5, wherein the flow disturbing portion is within a range of ± 20% of a cord length of the wing based on the primary throat position.   The said flow disturbance part is provided in the area | region of 50% or less of the length in the radial direction of this wing | blade from the radial outer end of the said blade, It is described in any one of Claim 1 to 6 Rotary machine.

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