JP2012041821A - Wing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wing device that can effectively suppress flow separation on a suction surface by a minimum flow resistance.SOLUTION: The wing device 3b includes: a pressure surface 15 that connects a front edge part 13 with a rear edge part 14; the suction surface 16 that is provided facing the pressure surface 15 and that is formed to project from the front edge part 13 to the rear edge part 14 and on which a negative pressure relatively acts to a pressure acting on the pressure surface 15; a notch step 20 that is provided on a side of the suction surface 16 along the front edge part 13 and that forms a step that is recessed toward the pressure surface 15 on the suction surface 16 where a width dimension of a wing length direction Y is formed so that the dimension gets narrower from a starting point 20a of a side of the front edge part 13 to and an end point 20b of an end part of a side of the rear edge part 14; and a protrusion 21 that is provided in a maximum switching point M where a curvature heading the rear edge part 14 from the front edge part 13 of the suction surface 16 is maximum, or is provided to project closer to the front edge part 13 than the maximum switching point M.

Description

  The present invention relates to a wing body for a fluid machine such as a gas turbine compressor or a cooling fan for a vehicle or for an aircraft.

  In general, a wing body used in a fluid machine or an aircraft has a wing surface that is relatively negative with respect to a pressure surface that receives pressure from a fluid and a pressure that acts on the pressure surface with respect to a front edge portion and a rear edge portion. It is divided into the suction surface that becomes pressure. For example, blades used in gas turbine compressors and vehicle cooling fans have a wing shape (cross section perpendicular to the blade length direction along the chord connecting the leading and trailing edges). The pressure of the fluid flowing along the positive pressure surface is increased, and the pressure of the fluid flowing along the negative pressure surface is set to a relatively negative pressure, thereby generating a driving force.

  Such a wing body is designed so that a design operation point such as a predetermined air volume, a static pressure, and a rotational speed is determined, and the wing shape is optimized. However, in actual use, it may be used at a higher load than the design operating point described above, and the fluid flowing along the suction surface will be peeled off, leading to noise and blade performance degradation.

  The blade body described in Patent Document 1 below forms an average surface roughness near the leading edge of the blade more coarsely than the average surface roughness on the pressure surface side and the suction surface side, and the turbulence transitions to the fluid flow. It is formed in the roughness which raises. In other words, this wing body is forced to make a turbulent transition of the working fluid flowing along the suction surface to suppress separation that occurs on the suction surface.

  Further, in the wing body of Patent Document 2 below, the apex angle with the highest height is installed at the upstream end of the air flow, and the back surface height decreases linearly toward the wake side, and the lateral width is linear. A plow material whose plane view increased to a triangular shape is provided on the blade surface. Thereby, it is supposed that the separation of the flow generated on the blade surface can be suppressed by the vertical vortex generated when the air current passes over the plow material.

JP 2000-104501 A JP 2003-108144 A

However, the wing body of Patent Document 1 adjusts the average surface roughness in the vicinity of the leading edge of the blade to cause turbulent transition, but merely causing turbulent transition has an effect of suppressing separation. There is a problem of being small. In particular, when dust is contained in the fluid, there is a problem that the effect of turbulent transition is reduced because the dust accumulates in the recesses on the surface of the blade leading edge, and the effect of suppressing separation is further reduced.

  In addition, the wing body of Patent Document 2 is provided with a plow material on the wing surface to generate a vertical vortex. However, when such a projection is disposed at the upper end of the airflow, in a state where separation is difficult to occur. There is a problem of functioning as a flow resistance. Moreover, in the state of the flow in which peeling is likely to occur, there is a problem that peeling occurring upstream of the plow material cannot be suppressed.

  The present invention has been made in view of the above-described circumstances, and provides a wing body that can effectively suppress the separation of the flow on the suction surface with a minimum flow resistance.

In order to solve the above problems, the present invention proposes the following means.
The wing body of the present invention is provided with a pressure surface that connects a front edge portion and a rear edge portion, and a pressure acts thereon, and is opposed to the pressure surface, and is curved in a convex shape from the front edge portion to the rear edge portion. A negative pressure surface on which the negative pressure acts relative to the pressure acting on the positive pressure surface, and is provided on the negative pressure surface side along the front edge, and is recessed toward the positive pressure surface side to form the negative pressure surface. A notch step portion formed so that a step is formed between the pressure surface and the width dimension in the blade length direction gradually decreases from the start end on the front edge side toward the end on the rear edge side, and the suction surface A maximum turning portion having a maximum curvature from the front edge portion to the rear edge portion, or a protrusion provided to protrude from the maximum turning portion toward the front edge portion.

  According to this configuration, since the notch step portion is provided at the front edge portion, a part of the fluid that has flowed to the suction surface side first flows into the notch step portion and rides on the suction surface from the notch step portion. . The fluid that rides on the suction surface forms a longitudinal vortex so as to be involved when riding, and this longitudinal vortex flows downstream along the suction surface. That is, this longitudinal vortex attracts a high-energy fluid in the vicinity of the suction surface and suppresses the development of the boundary layer in the vicinity of the suction surface, so that the peeling suppression effect can be increased. Moreover, since the notch level | step-difference part is provided along the front edge part, the peeling which arises in the upstream of a suction surface can be suppressed effectively. Furthermore, since the notch step portion is recessed toward the pressure surface, the flow resistance can be reduced as compared with the case where a protrusion is provided on the suction surface. On the other hand, on the suction surface, a protrusion is provided on the downstream side of the notch step portion and on the leading edge side of the maximum turning portion or the maximum turning portion with the maximum curvature, and the protrusion causes the flow along the suction surface. A vertical vortex is newly formed. For this reason, even if the longitudinal vortex formed by the notch step portion weakens at the maximum turning portion where separation is relatively likely to occur due to a large change in the flow direction, separation occurs due to the longitudinal vortex generated by the protrusion. Can be effectively suppressed.

  In the above wing body, the surface of the notch step portion forming the step is formed in a convex shape from the start end to the end.

  According to this configuration, the surface of the notch step portion that forms the step is formed in a convex shape from the start to the end, so that the width of the notch step portion that is defined by the distance between the surfaces that form the steps facing each other. Is set to be large at the starting end and decreases at a high reduction rate from the starting end to the intermediate portion. On the other hand, from the intermediate part to the terminal part, the width of the notch step part decreases with a relatively low reduction rate with a small width. Therefore, at the starting end, the fluid flowing on the suction side is effectively allowed to flow into the notch step portion, and the width is reduced at a high reduction rate, so that the fluid flowing into the notch step portion is discharged to generate a vertical vortex. Further, by decreasing at a relatively low reduction rate from the intermediate portion to the end portion, the fluid can flow out from the intermediate portion to the end portion in a well-balanced manner to form a vertical vortex.

  Further, in the above wing body, the notch step portion has a change rate of a cross-sectional area as viewed from the front edge side toward the rear edge side, from at least midway on the front edge side to the rear edge side. It is characterized by being formed to be constant.

  According to this configuration, the rate of change in the cross-sectional area of the notch step portion is constant from at least halfway on the front edge side to the rear edge side. The fluid can be allowed to flow out at a constant flow rate to form a uniform vertical vortex, thereby effectively suppressing separation.

  The wing body is characterized in that a plurality of the notch step portions and the projection portions are provided so as to be located at different positions in the blade length direction.

  According to this configuration, the notch step portion and the projection portion are located at different positions in the blade length direction so that the vertical vortex generated at the notch step portion and the vertical vortex generated at the projection portion do not overlap each other. The longitudinal vortex can be generated in a well-balanced manner over the entire blade length direction, and separation can be suppressed.

  In the above wing body, the protrusion projects from the suction side to the rear edge side so that the height of the projection protrudes from the suction surface as the curvature of the suction surface increases. It is characterized in that a plurality are provided.

  According to this configuration, a plurality of protrusions are provided from the front edge toward the rear edge, so that the stepped portion and the plurality of protrusions gradually increase the front edge toward the rear edge. Longitudinal vortices can be generated. In addition, the height at which the protrusion protrudes from the front edge toward the rear edge according to the curvature of the suction surface increases, so that vertical vortices are generated more effectively at locations with high curvature. Thus, the flow resistance can be suppressed to a minimum at a portion having a relatively low curvature and hardly causing the separation while suppressing the separation.

  Further, the wing body of the present invention is provided with a pressure surface on which a pressure acts by connecting a front edge portion and a rear edge portion, and opposed to the pressure surface, and is convex from the front edge portion to the rear edge portion. A negative pressure surface that is formed in a curved shape and has a negative pressure acting relative to the pressure acting on the positive pressure surface, and is provided on the negative pressure surface side along the blade leading edge, and is depressed on the positive pressure surface side. A notch step portion formed with a step between the suction surface and a width dimension in the blade length direction that gradually decreases from the front edge side toward the rear edge side. The surface of the portion forming the step is formed in a convex shape from the start end on the front edge side to the end on the rear edge side.

  According to this configuration, since the notch step portion is provided at the front edge portion, a part of the fluid that has flowed to the suction surface side first flows into the notch step portion and rides on the suction surface from the notch step portion. . The fluid that rides on the suction surface forms a longitudinal vortex so as to be involved when riding, and this longitudinal vortex flows downstream along the suction surface. That is, this longitudinal vortex attracts a high-energy fluid in the vicinity of the suction surface and suppresses the development of the boundary layer in the vicinity of the suction surface. Moreover, since the notch level | step-difference part is provided along the front edge part, the peeling which arises in the upstream of a suction surface can be suppressed effectively. Furthermore, since the notch step portion is recessed toward the pressure surface, the flow resistance can be reduced as compared with the case where a protrusion is provided on the suction surface. Further, since the surface forming the step of the notch step portion is formed in a convex shape from the start end to the end, the width of the notch step portion defined by the distance between the surfaces forming the step facing each other is In addition to being set large, it decreases at a high reduction rate from the beginning to the middle. On the other hand, from the intermediate part to the terminal part, the width of the notch step part decreases with a relatively low reduction rate with a small width. Therefore, at the start end, the fluid flowing toward the suction surface side is effectively allowed to flow into the notch step portion, and the width is decreased at a high reduction rate so that the fluid flowing into the notch step portion is caused to flow out. By causing the vortex to be generated and further decreasing at a relatively low reduction rate from the intermediate portion to the end portion, the fluid can flow out in a balanced manner from the intermediate portion to the end portion to form a vertical vortex.

  In the above wing body, the surface of the notch step portion that forms the step is a steep wall surface that forms a ridge with the negative pressure surface.

According to this configuration, the fluid that has flowed into the notch stepped portion collides with or flows along the steep wall surface, and forms a strong vertical vortex so as to involve a ridge when riding on the suction surface. Development can be further suppressed, and the peeling suppression effect can be further increased.

  In the above wing body, the bottom surface of the notch step portion gradually becomes shallower as it advances from the start end to the end, and the end is smoothly connected to the suction surface with a curvature.

According to this configuration, the fluid that has flowed into the notch step portion that has flowed to the end is smoothly guided to the negative pressure surface, so that an increase in pressure loss can be suppressed.

  In the wing body, a plurality of the notch step portions are provided along the front edge portion, and the negative notch is seen between two adjacent notch step portions from the normal direction of the suction surface. A feature is that a delta portion in which the pressure surface remains in a substantially triangular shape is formed.

According to this configuration, since a plurality of notch steps are provided continuously along the blade leading edge, a longitudinal vortex can be formed in a wide range in the blade width direction. Thereby, peeling can be suppressed in a wide range in the blade width direction.

  According to the wing body of the present invention, it is possible to effectively suppress the separation of the flow on the suction surface with the minimum flow resistance.

1 is a schematic diagram of a gas turbine according to a first embodiment of the present invention. In the compressor of the gas turbine of the 1st Embodiment of this invention, it is a perspective view which shows the detail of a compressor moving blade. In the compressor rotor blade of the 1st Embodiment of this invention, it is sectional drawing orthogonal to a blade length direction. It is a fragmentary perspective view which shows the detail of a front edge part and a suction surface in the compressor moving blade of the 1st Embodiment of this invention. It is sectional drawing in the cutting line II-II of FIG. FIG. 5 is a plan view taken along arrow III in FIG. 4. It is a graph showing the shape of the suction surface in the compressor rotor blade of the first embodiment of the present invention, and (a) an angle formed by a position along the chord on the suction surface and a tangent line of the chord and the suction surface; (B) is a graph showing the relationship between the position along the chord on the suction surface and the rate of change of the angle between the chord and the tangent to the suction surface. It is action | operation explanatory drawing of the compressor rotor blade of the 1st Embodiment of this invention, Comprising: It is sectional drawing which shows the state at the time of low load driving | operation. It is operation | movement explanatory drawing of the compressor blade of the 1st Embodiment of this invention, Comprising: It is a fragmentary perspective view which shows the state at the time of low load driving | operation. It is operation | movement explanatory drawing of the compressor rotor blade of the 1st Embodiment of this invention, Comprising: It is sectional drawing which shows the state at the time of high load operation. It is a fragmentary perspective view which shows the detail of a front edge part and a suction surface in the compressor rotor blade of the modification of the 1st Embodiment of this invention. It is a partial top view which shows the detail of the front edge part and suction surface of the compressor blade of the 2nd Embodiment of this invention. It is a fragmentary sectional view which shows the detail of the front edge part of the compressor moving blade of the 2nd Embodiment of this invention. It is a graph showing the shape of a notch step part in the compressor rotor blade of the 2nd Embodiment of this invention, Comprising: (a) The graph showing the relationship between the position from a start end, and the width | variety of a notch step part, (b) From the start end (C) a graph showing the relationship between the position from the starting end and the cross-sectional area of the notch step portion, (d) a cross-sectional area of the position from the starting end and the notch step portion It is a graph showing the relationship with the change rate of. It is a perspective view which shows the detail of the compressor rotor blade of the 3rd Embodiment of this invention. In the compressor rotor blade of the 4th Embodiment of this invention, it is sectional drawing orthogonal to a blade length direction. It is a front view which shows the propeller fan as other embodiment to which the wing | blade body of this invention is applied. It is a perspective view which shows the detail of the wing | blade body of the propeller fan shown in FIG.

(First embodiment)
A first embodiment according to the present invention will be described below with reference to the drawings.
FIG. 1 shows a gas turbine as an example to which the wing body of the present invention is applied.
As shown in FIG. 1, a gas turbine 1 includes a rotor 2, a compressor 3 that generates compressed air, and a combustor 4 that generates fuel gas G by supplying fuel to the compressed air supplied from the compressor 3. And a turbine 5 that is rotationally driven by the combustion gas G supplied from the combustor 4. The compressor 3 includes a compressor casing 3a disposed on the outer periphery of the rotor 2, a plurality of compressor blades 3b fixed to the rotor 2 and arranged in an annular shape, and an annular arrangement supported by the compressor casing 3a. The compressor rotor blades 3b and the compressor stator blades 3c are alternately arranged in a plurality of stages in the turbine axial direction R. The turbine 5 includes a turbine casing 5a disposed on the outer periphery of the rotor 2 and having a combustion gas flow path F therein, a plurality of turbine rotor blades 5b fixed to the rotor 2 and arranged in an annular shape, and a turbine casing 5a. A plurality of turbine stationary blades 5c that are supported and arranged in an annular shape are provided, and the turbine rotor blades 5b and the turbine stationary blades 5c are alternately arranged in a plurality of stages in the turbine axial direction R. And in 1st Embodiment, the blade body which shows the one aspect | mode of this invention is applied to the compressor rotor blade 3b. Details are shown below.

  As shown in FIG. 2, the compressor rotor blade 3 b includes a blade body 10 whose section is an airfoil, a platform 11 provided so as to protrude from the base end of the blade body 10, and a base 11 protruding from the platform 11. The blade root 12 is provided. The blade root 12 is formed with a serration 12a having a shape corresponding to a blade groove (not shown) formed in the rotor 2, and the compressor rotor blade 3b is inserted into the blade groove 12 by fitting the blade root 12 into the blade groove (not shown). The blade 10 is fixed to the rotor 2 such that the blade length direction Y of the main body 10 is the radial direction of the rotor 2.

  The blade body 10 is connected to the front edge 13 on the upstream side in the flow direction of the compressed air flow, the rear edge 14 on the downstream side in the flow direction, and the positive edge on which the pressure acts. The pressure surface 15 and the negative pressure surface 16 provided opposite to the positive pressure surface 15 and having a negative pressure acting on the pressure acting on the positive pressure surface 15 are provided. As shown in FIG. 3, in the present embodiment, in the blade body 10, in the cross section orthogonal to the blade length direction Y, the pressure surface 15 forms a convex curved surface, the suction surface 16 forms a concave curved surface, and the leading edge It is formed in an arcuate shape as a whole so that the width dimension gradually decreases from the portion 13 side to the rear edge portion 14 side. Further, the surfaces of the leading edge portion 13 and the trailing edge portion 14 are formed in curved surfaces having a substantially arc shape in a cross section perpendicular to the blade length direction Y so as to smoothly connect the positive pressure surface 15 and the negative pressure surface 16. . The compressor rotor blade 3b is designed so that a predetermined air flow, static pressure, rotation speed, and other design operation points are determined, and the blade shape is optimized.

  As shown in FIGS. 2 and 3, the blade body 10 is provided on the suction surface 16 side along the front edge portion 13, and is recessed on the pressure surface 15 side to form a step with the suction surface 16. A notch step 20 and a protrusion 21 provided on the rear edge 14 side of the notch step 20 are provided. A plurality of notch step portions 20 are continuously formed on the negative pressure surface 16 along the front edge portion 13, and a delta portion 22 is formed between adjacent notch step portions 20.

4 is an enlarged perspective view of the notched stepped portion 20 and the protruding portion 21, FIG. 5 is a sectional view taken along the line II-II in FIG. 4, and FIG. 6 is a view taken in the direction of arrow III in FIG.
As shown in FIG. 6, the notch step portion 20 has an isosceles triangle shape when viewed from the normal direction of the suction surface 16, and the end 20 b on the rear edge portion 14 side is directed to the rear edge portion 14 side. , The leading edge 20a on the front edge 13 side is formed to be the bottom. That is, the notch step portion 20 is gradually reduced in width dimension P in the blade length direction Y from the start end 20a on the front edge 13 side to the end 20b on the rear edge 14 side.

  As shown in FIG. 3, the notch step portion 20 has a chord length L (the length of a straight line connecting the front edge portion 13 and the rear edge portion 14), and a notch length D (start end 20a and end end 20b). In this embodiment, D / L = 0.05.

  As shown in FIG. 5, the notch step portion 20 includes a bottom surface 20 c and side surfaces 20 d and 20 e that form a step between the bottom surface 20 c and the negative pressure surface 16. The bottom surface 20c is connected to the surface 13a of the front edge 13 at the start end 20a, and is connected to the negative pressure surface 16 at the end 20b. Further, the side surfaces 20d and 20e form a ridge side (angular side) 23 together with the negative pressure surface 16 as a wall surface, and also form a corner portion 24 with θ = 90 ° together with the bottom surface 20c.

As shown in FIG. 6, the delta portion 22 is a portion where the suction surface 16 remains in an isosceles triangle shape when viewed from the normal direction of the suction surface 16. The apex is directed to the edge 13 side, and the base is directed to the rear edge 14 side.
As shown in FIG. 6, in the present embodiment, the delta portion 22 is set so that the apex angle α, which is an angle formed at the apex, is 60 °.
Further, as shown in FIG. 5, the depth of the notch step portion 20, that is, the height from the bottom surface 20 c to the suction surface 16 of the delta portion 22 (more precisely, in contact with the bottom surface 20 c and the suction surface 16 in the airfoil. In this embodiment, Hmax / W is 0.3, where H is the diameter of the inscribed circle) and W is the dimension between the terminal ends 20b of the adjacent notch step portions 20.

  Further, as shown in FIGS. 3 and 4, the protrusion 21 is formed in, for example, a triangular pyramid shape, and one apex 21 a of the triangle constituting the bottom connected to the suction surface 16 is directed to the front edge 13 side. It is arranged to face. Further, in the protrusion 21, the ridge line 21 c with respect to the inclination of the ridge line 21 c connecting the vertex 21 a facing the front edge 13 and the vertex 21 b facing the bottom surface and protruding from the suction surface 16 with respect to the suction surface 16. The inclination of the side surface 21d facing the rear edge portion 14 facing the negative pressure surface 16 is set to a gentle angle. FIG. 7 shows an example of the suction surface shape. In FIG. 7A, in the cross section orthogonal to the blade length direction, the position of the chord direction on the suction surface and the angle φ of the tangent to the suction surface with respect to the chord (B) is a graph showing the relationship between the position in the chord direction on the suction surface and the rate of change of the angle φ, that is, the curvature of the suction surface. Note that the position in the chord direction on the suction surface is represented by a distance N from the connection portion, where 0 is a connection portion with the front edge portion of the suction surface. As shown in FIG. 7 (a), in this example, the leading edge side has a certain angle with respect to the chord, the angle changes greatly toward the trailing edge side, and gradually becomes parallel to the chord. That is, the angle φ formed approaches 0, and then the angle formed with the chord becomes a negative value, thereby forming a convex curved surface as a whole. Further, as shown in FIG. 7B, the curvature of the suction surface gradually increases from the front edge portion to the intermediate portion, becomes the maximum turning portion where the curvature becomes maximum at a certain position, and then goes to the rear edge portion 14. The curvature is getting smaller. As shown in FIG. 3, the protruding portion 21 has a maximum turning portion M in which the curvature from the leading edge portion 13 to the trailing edge portion 14 of the suction surface 16 becomes maximum in a cross section orthogonal to the blade length direction Y. Is provided. Further, in the present embodiment, the protrusion 21 is formed so that the position of the notch step portion 20 and the blade length direction Y is different, that is, the delta portion 22 formed between the notch step portions 20 and the blade length direction Y. Are arranged so that their positions coincide.

Next, the operation of the wing body 10 having the above configuration will be described.
First, as shown in FIG. 1, the rotor 27 is rotationally driven and the compressor blades 3b are rotated in the compressor 3, so that the intake air is compressed by the compressor blades 3b and burned as compressed air. Supplied to the vessel 4. At this time, the air compressed by the compressor rotor blade 3b is divided into an air flow along the pressure surface 15 and an air flow along the negative pressure surface 16 at the front edge portion 13 and flows toward the rear edge portion 14 side. From the part 14, it flows into between the compressor stationary blades 3c behind it.

  In the process of flowing along the positive pressure surface 15, the air flow along the positive pressure surface 15 is gradually increased in pressure and discharged from the rear edge portion 14. On the other hand, part of the airflow along the negative pressure surface 16 becomes a vertical vortex T <b> 1 due to the notched stepped portion 20, and flows backward along the negative pressure surface 16. Furthermore, part of the airflow flowing backward along the negative pressure surface 16 collides with the protrusion 21 and becomes a vertical vortex T2 and flows along the negative pressure surface 16 to the rear edge 14 side. Hereinafter, the details of the operation of the notch step portion 20 and the projection portion 21 with respect to the airflow will be described.

First, the effect | action of vertical vortex formation in the notch level difference part 20 is demonstrated.
As shown in FIGS. 8 and 9, most of the airflow that flows along the suction surface 16 from the front edge portion 13 is divided into a plurality of parts and flows into the notch step portions 20. And the airflow which flowed into this notch level | step-difference part 20 collides with the side surfaces 20d and 20e, or flows along the side surfaces 20d and 20e, and some of them run on the negative pressure surface 16 which adjoins. At this time, the airflow riding on the suction surface 16 forms a strong vertical vortex T1 so as to involve the ridge 23 as shown in FIG. As shown in FIG. 9, the longitudinal vortex T1 gradually increases and becomes stronger at each ridge side 23 as it proceeds from the start end 20a side to the end end 20b side. In other words, the vertical vortex T1 increases while the center of the vertical vortex T1 moves in the blade length direction Y along the edge 23, and the vertical vortex T1 flows downstream when reaching the end 20b. The longitudinal vortex T <b> 1 formed in this way is well maintained up to the downstream side of the suction surface 16.

  At the time of operation below the predetermined design operating point of the compressor 3 (at the time of low load operation), as shown in FIG. 8, the inflow angle of the air flow with respect to the front edge portion 13 is within the assumed range, and the negative pressure surface 16 also Flow separation is unlikely to occur. Even in such a state, the notch step portion 20 forms the vertical vortex T1, but since it is recessed toward the positive pressure surface 15, the flow resistance against the airflow is small.

  At the time of operation exceeding the predetermined design operating point of the compressor 3 (during high load operation), as shown in FIG. 10, the inflow angle of the airflow with respect to the front edge portion 13 becomes unexpected and the suction surface 16 The flow separation tends to occur on the upstream side. Even in such a state, the vertical vortex T <b> 1 formed by the notch step portion 20 attracts the high energy fluid on the upstream side of the suction surface 16. That is, when the high energy fluid is attracted to the vicinity of the suction surface 16, the development of the boundary layer that becomes low energy is suppressed, and the occurrence of separation is hindered.

  On the other hand, in the protrusion 21, the airflow branched in the blade length direction Y at the ridge line 21 c on the front edge 13 side flows along both side surfaces forming the ridge line 21 c, and the side surfaces facing the side surface and the rear edge portion 14 side. Overcoming the ridge line formed between 21d and 21d, a strong vertical vortex T2 is formed at this time. Here, the protruding portion 21 is provided in the maximum turning portion M where the curvature is maximum on the suction surface 16. For this reason, even if the vertical vortex T1 formed by the notch step portion 20 is weakened, the vertical vortex T2 is newly formed by the protrusion 21 so that the airflow along the suction surface 16 has a maximum curvature. It can suppress effectively that it peels in the part M and its vicinity.

  As described above, in the compressor rotor blade 3b of the present embodiment, the flow resistance is prevented from increasing by the notch step portion 20, and the longitudinal vortex T1 is generated at the front edge portion 13 and the downstream separation from the front edge portion 13 occurs. In addition, the protrusion 21 capable of suppressing the separation by generating the vertical vortex T2 on the suction surface 16 is disposed in the maximum turning portion M where the separation is most likely to occur, thereby minimizing the flow resistance. It is possible to effectively suppress peeling while restraining to a low level. In such a compressor 3 provided with a plurality of compressor blades 3b, even during high-load operation, the compressor 3 operates stably and compresses air without causing vibration or the like due to separation. Can be supplied to the vessel 4.

  Further, in the present embodiment, the side surfaces 20d and 20e form the negative pressure surface 16 and the ridge side 23 in the notch step portion 20, so that the airflow collides with the side surfaces 20d and 20e or flows along the side surfaces 20d and 20e and is negative. When riding on the pressure surface 16, a strong vertical vortex T1 is formed so as to involve the ridge 23. Thereby, the development of the boundary layer can be further suppressed, and the peeling suppression effect can be further increased.

  In addition, since a plurality of notch step portions 20 are continuously provided along the front edge portion 13, the longitudinal vortex T <b> 1 can be formed in a wide range in the blade length direction Y. Thereby, in the wide range of the blade length direction Y, peeling of airflow can be suppressed. Further, since the notch step 20 and the protrusion 21 are located at different positions in the blade length direction Y, the vertical vortex T1 generated at the notch step 20 and the vertical vortex T2 generated at the protrusion 21 do not overlap each other. In other words, longitudinal vortices can be generated in a well-balanced manner in the entire blade length direction Y to suppress separation.

  In the above-described configuration, the D / L value is set to 0.05 in the notch step portion 20, but the value is not limited to this value, and other values can be set. However, it is desirable to set under the condition of D / L <0.1. Similarly, although the value of Hmax / W is 0.3, the value is not limited to this value and can be set to other values. However, it is desirable to set in the range of 0.2 ≦ Hmax / W ≦ 0.5.

  Further, in the configuration described above, the angle of the corner portion 24 is perpendicular to the bottom surface 20c (θ = 90 °), but may be formed to have another angle. At this time, if it is formed so as to be θ = 90 to 120 °, the longitudinal vortex T1 is satisfactorily formed. Further, in the configuration described above, the ridge side 23 is formed, but chamfering may be performed without providing the ridge side 23. In the configuration described above, the apex angle α of the delta portion 22 is 60 °, but other angles may be used. At this time, when 50 ° ≦ α ≦ 70 °, the vertical vortex T1 is formed satisfactorily.

  Moreover, in the said embodiment, although the shape of the bottom face 20c of the notch level | step-difference part 20 shall be triangular shape and formed so that the width | variety P may become zero at the terminal end 20b, it is not restricted to this. As shown in FIG. 11, the end 20b may have a certain width and be formed in a trapezoidal shape as a whole. By doing in this way, the separation distance of vertical vortex T1 formed over each of the mutually opposing side surfaces can be maintained, and vertical vortices do not interfere with each other. That is, the high-density vertical vortex T1 is formed over a wide range in the blade length direction Y, attracts a high energy fluid near the suction surface 16, and further suppresses the development of the boundary layer. Thereby, the fluid peeling suppression effect can be further increased. Alternatively, the bottom surface 20c may be smoothly connected to the suction surface 16 with a curvature at the end 20b. By doing in this way, since the airflow which flowed into the notch level | step-difference part 20 and flowed to the termination | terminus 20b is smoothly guide | induced to the negative pressure surface 16, the increase in pressure loss can be suppressed.

  Further, in the present embodiment, the projecting portion 21 has a triangular pyramid shape and has a ridge line 21c on the front edge portion 13 side and an inclined surface 21d on the rear edge portion 14 side facing the ridge line 21c. However, the present invention is not limited to this, and the direction may be reversed. In this case, the vertical vortex T2 is formed when the airflow from the front edge 13 side passes over the inclined surface 21d. Furthermore, the shape of the protrusion 21 is not limited to the triangular pyramid shape. If the protrusion 21 is at least a protrusion that guides the airflow in a direction away from the suction surface 16, the guided airflow gets over the protrusion 21. In this case, the vertical vortex T2 can be formed. Further, the position where the protrusion 21 is provided is the maximum turning portion M, but the present invention is not limited to this, and the vertical vortex T2 formed by the protrusion 21 is also formed on the front edge 13 side of the maximum turning portion M. By making it flow on the maximum turning portion M, separation in the vicinity of the maximum turning portion M can be effectively suppressed.

  In the present embodiment, the protrusions 21 are arranged in a row in the blade length direction Y, but the present invention is not limited to this. For example, if the cross-sectional shape changes in the blade length direction Y even if it is disposed in the maximum turning portion M, the position of the maximum turning portion M at which the curvature becomes maximum from the front edge portion 13 toward the rear edge portion 14 is also the blade. Each cross section orthogonal to the longitudinal direction Y is different, and accordingly, the arrangement of the protrusions 21 may be an arrangement that is not parallel to the blade length direction Y.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. 12 to 14 show a second embodiment of the present invention. In this embodiment, the same members as those used in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The second embodiment is characterized by the shape of the notch step portion. As shown in FIGS. 12 and 13, the notch step portion 30 of the present embodiment has side surfaces 30 d and 30 e that form a step from the start end 30 a on the front edge portion 13 side to the end point 30 b on the rear edge portion 14 side. It is formed in a curved surface that is curved in a convex shape. For this reason, as shown in FIG. 14A, the width P of the notch step portion 30 defined by the distance between the side surfaces 30d and 30e facing each other is set large at the start end 20a and is intermediate from the start end 30a. It decreases at a high rate of reduction over the part. On the other hand, from the intermediate portion to the end portion 30b, the width P of the notch step portion 30 decreases with a small width and a relatively low reduction rate. In FIG. 14, the horizontal axis Q represents the position in the notch step portion 20 as a linear distance from the start end 20a to the end point 20b. Further, as shown in FIG. 13, the bottom surface 30c of the notch step portion 30 is substantially parallel to the cross-sectional center line L10 of the wing body 10 at the start end 30a, and is gradually curved concavely so as to face the suction surface 16. Yes. Therefore, as shown in FIG. 14B, the depth H defined by the surface 13a and the suction surface 16 of the front edge 13 and the bottom surface 20c is the shape of the surface 13a of the front edge 13 on the start end 20a side. As a result, the surface increases from the surface 13a of the front edge portion 13 to the suction surface 16 along the cross-sectional center line L10. On the other hand, from the intermediate portion to the end 20b, the angle formed with the cross-sectional center line L10 increases so that the bottom surface 20c faces the suction surface 16, so that the change in the depth H changes from increase to decrease. It is formed such that the reduction rate increases and the depth H decreases rapidly. Then, as shown in FIGS. 14 (c) and 14 (d), the cross-sectional area as viewed from the front edge portion 13 side toward the rear edge portion 14 side of the notch step portion 30 obtained by the product of the width P and the depth H. A is set so that the change rate dA / dQ decreases at a substantially constant change rate from the intermediate portion to the terminal end 30b.

  In the present embodiment, the side surfaces 30d and 30e forming the step of the notch step portion 30 are formed in a convex shape from the start end 30a to the end 30b, so that the side surfaces 30d and 30e forming the step facing each other are spaced apart from each other. The defined width P of the notch step portion 30 changes as described above. For this reason, at the start end 30a, the airflow flowing toward the suction surface 16 side is effectively allowed to flow into the notch step portion 30, and the airflow flowing into the notch step portion 30 is discharged by decreasing the width P at a high reduction rate. The vertical vortex T1 is generated. Furthermore, since the width P decreases at a relatively low reduction rate from the intermediate portion to the end 30b, the vertical vortex T1 can be formed by allowing the air flow to flow out in a balanced manner from the intermediate portion to the end 30b. Further, in the present embodiment, the side surfaces 30d and 30e are formed into convex curved surfaces as described above, the width P defined by the side surfaces 30d and 30e, and the bottom surface 30c are the surface 13a and the suction surface 16 of the front edge portion 13. The cross-sectional area A is constant from the intermediate portion to the terminal end 30b from the relationship with the depth H defined by the above, so that the air flow is allowed to flow out at a constant flow rate over the entire range where the constant change rate is obtained. By forming the uniform longitudinal vortex T1, peeling can be effectively suppressed.

(Third embodiment)
Next, a third embodiment of the present invention will be described. 15 and 16 show a third embodiment of the present invention. In this embodiment, the same members as those used in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 15 and 16, the compressor blade 40 of this embodiment includes a plurality of protrusions 21 from the front edge 13 side toward the rear edge 14 side. More specifically, in the present embodiment, protrusions 21 (21A, 21B) are provided at two locations from the front edge 13 side toward the rear edge 14 side. Here, the height of the protrusions 21 </ b> A and 21 </ b> B protruding from the suction surface 16 is set higher as the curvature of the suction surface 16 increases, and the rear edge portion 14 relatively close to the maximum turning portion M. The side protrusion 21B is set higher.

  In the compressor rotor blade 40 of the present embodiment, a plurality of protrusions 21 (21A, 21B) are provided from the front edge portion 13 toward the rear edge portion 14, so that the notch step portion 30 and the plurality of protrusion portions 21 ( 21A and 21B), it is possible to generate longitudinal vortices T1 and T2 stepwise from the front edge portion 13 to the rear edge portion 14 to suppress peeling more effectively. Further, the height of the protrusion 21 (21A, 21B) protruding from the front edge 13 toward the rear edge 14 in accordance with the curvature of the suction surface 16 is increased, thereby providing a portion with a high curvature. Then, while generating the vertical vortex T2 more effectively and suppressing the separation, the flow resistance can be suppressed to a minimum at a location where the curvature is relatively low and the separation is difficult to occur.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  In each of the above embodiments, the compressor rotor blades 3b and 40 are provided with the notched step portions 20 and 30 and the protrusions 21. However, the present invention is not limited to this, and the compressor rotor blades 3b and 40 are provided with the compressor stationary blade 3c. Produces the same effect. Moreover, it is good also as what applies to the turbine rotor blade 5b and the turbine stationary blade 5b. Furthermore, the blade body provided with the notched step portions 20 and 30 and the protrusion 21 is not limited to the compressor blade 3b, the compressor blade 3c, the turbine blade 5b, and the turbine blade 5c in the gas turbine 1. Applicable to various wing bodies. For example, as shown in FIGS. 17 and 18, a rotary impeller 51 of a propeller fan 50 used as a vehicle cooling fan is provided with a notch step portion 53 along a front edge portion 52 a of the propeller 52, and the propeller 52 In the negative pressure surface 54, the maximum turning portion M or the protrusion 55 may be provided closer to the front edge portion 52a than the maximum turning portion M. Also in this case, the same effect as described above is obtained. Further, the present invention is not limited to a wing body incorporated in a rotating machine such as the gas turbine 1 or the propeller fan 50, but can be applied to a wing body used in an aircraft, for example, a main wing of an airplane. In each of the above embodiments, the compressor rotor blades 3b and 40, which are blade bodies, have a concave surface on the pressure surface, a convex surface on the suction surface, and have an arcuate shape as a whole. However, the shape is not limited to this, and various shapes can be used depending on the application. For example, the present invention can be applied to a wing body in which not only the suction surface but also the pressure surface is a convex curved surface, or a wing body formed in an S shape as a whole.

3b, 40 Compressor blade (wing body)
13 Front edge portion 14 Rear edge portion 15 Pressure surface 16 Vacuum pressure surface 20, 30 Notch stepped portions 20a, 30a Start end 20b, 30b End 21 Projection portion 22 Delta portion M Maximum turning portion Y Blade length direction

Claims (10)

A pressure surface connecting the front edge and the rear edge and acting on pressure,
A negative pressure surface that is provided opposite to the positive pressure surface, is formed to be convexly curved from the front edge portion to the rear edge portion, and a negative pressure acts on the pressure acting on the pressure surface;
Provided on the suction surface side along the front edge portion, and is recessed toward the pressure surface side to form a step between the suction surface and the width dimension in the blade length direction from the start end on the front edge side. A notch step portion formed so as to gradually become smaller toward the end on the rear edge side,
A wing body comprising: a maximum turning portion having a maximum curvature from the front edge portion to the rear edge portion of the suction surface or a protruding portion provided to protrude toward the front edge portion from the maximum turning portion. . The wing body according to claim 1,
The wing body is characterized in that the surface of the notch step portion forming the step is formed in a convex shape from the start end to the end. The wing body according to claim 2,
The notch step portion is formed such that the change rate of the cross-sectional area viewed from the front edge side toward the rear edge side is constant from at least the middle of the front edge side to the rear edge side. A wing body characterized by being. In the wing body according to any one of claims 1 to 3,
A wing body, wherein a plurality of the notch step portions and the projection portions are provided at different positions in the wing length direction. In the wing body according to any one of claims 1 to 4,
A plurality of the projecting portions are provided from the front edge side to the rear edge side so that the height protruding from the suction surface increases as the curvature of the suction surface increases. Wing body characterized by. A pressure surface connecting the front edge and the rear edge and acting on pressure,
A negative pressure surface that is provided opposite to the positive pressure surface, is formed to be convexly curved from the front edge portion to the rear edge portion, and a negative pressure acts on the pressure acting on the pressure surface;
Provided on the suction surface side along the blade leading edge, and is recessed toward the pressure surface side to form a step between the suction surface and the width dimension in the blade length direction from the leading edge side to the trailing edge A notch step portion formed so as to gradually become smaller toward the part side,
The wing body is characterized in that a surface of the notch step portion forming the step is formed in a convex shape from the start end on the front edge side to the end on the rear edge side. In the wing body according to any one of claims 1 to 6,
The wing body characterized in that a surface of the notch step portion that forms the step is a wall surface that forms a ridge with the negative pressure surface. In the wing body according to any one of claims 1 to 7,
The bottom surface of the notch step portion gradually becomes shallower as it goes from the start end to the end, and the end is smoothly connected to the suction surface with a curvature. In the wing body according to any one of claims 1 to 8,
A plurality of the notch step portions are provided along the front edge portion,
The wing body is characterized in that a delta portion in which the suction surface remains in a substantially triangular shape as viewed from the normal direction of the suction surface is formed between two adjacent cutout step portions. The wing body according to claim 9,
The wing body is characterized in that the notch step portion is set to have a width dimension in the blade length direction of the terminal end that is equal to or larger than an interval between adjacent notch step portions.

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