JP5456186B2 - Wing body and rotating machine - Google Patents

Description

  The present invention relates to a blade body and a rotary machine applied to a rotary machine such as a turbine section of a gas turbine, a compressor, a fan, a steam turbine, and a windmill, and particularly relates to a rear edge shape thereof.

Conventionally, in a blade body applied to a rotating machine such as a turbine portion of a gas turbine, a relatively thick thickness is given to increase the strength, and the trailing edge is formed into a circular arc (substantially semicircle) or There is a case where the shape is a straight line cut substantially perpendicular to the camber line. In this way, when a circular arc shape with a perfect circle or a linear shape cut perpendicular to the camber line is adopted as the trailing edge, the thickness of the trailing edge becomes relatively large, so that the flow generated on the blade surface is separated. Since the wake from the trailing edge is relatively large, the loss of flow or the channel resistance has increased.
Therefore, there has been proposed a wing body in which the angle of the connection point between the end of the ventral side edge line and the end of the back side edge line of the wing body of a straight line or a curve with a large curvature radius is formed substantially perpendicularly (for example, Patent Document 1).

JP 2005-76533 A

  However, in the conventional rotating machine described above, since the ratio of the flow loss and the flow path resistance due to the wake of the blade body is still high in the total loss, the loss due to this wake is further reduced. It is desired to improve efficiency.

  The present invention has been made in view of the above circumstances, and a wing body and a rotation that can reduce flow loss and flow resistance caused by wakes from the trailing edge caused by separation of the flow on the blade surface of the wing body Provide machines.

The present invention adopts the following configuration in order to solve the above-described problems and achieve the object.
The wing body according to the present invention (for example, the moving blades 1, 21, 31 in the embodiment) has a main body (for example, the back surface (for example, the back surface 2 in the embodiment) and the abdominal surface (for example, the abdominal surface 3 in the embodiment). A rear edge portion (for example, 6, 26, 36 in the embodiment) that connects the main body portion 4) in the embodiment and the back surface and the abdominal surface with continuous curved surfaces (for example, the curved surfaces 5, 25, 35 in the embodiment). The curved surface of the rear edge portion is a rear end portion located at the most downstream side in the fluid flow direction from either the back surface or the abdominal surface (for example, the rear end portions 7, 27, 37 in the embodiment). ), The radius of curvature gradually decreases toward the rear end, and the radius of curvature becomes the smallest at the rear end. Thereafter, the radius of curvature gradually increases from the rear end toward the back surface or the abdominal surface. Back or belly Either reaches the other of said rear end, characterized in that it is arranged on the back side or ventral side than the extended line of the camber line of the main body portion.
According to the wing body according to the present invention, the curved surface of the rear edge portion continuous with the back surface or the abdominal surface of the main body portion is thinned as the radius of curvature gradually decreases and approaches the rear end portion. On the other hand, compared to the case where the cross-sectional shape is simply a semi-circular shape like the conventional rear edge, or the angle of the connection point between the end of the back side edge line and the end of the abdominal side edge line is substantially vertical. Since the vicinity of the rear end can be made thin, the separation position of the flow from the blade surface moves rearward and the wake from the rear edge becomes thinner, reducing flow loss and improving efficiency. Can do.

  In addition, even when the rear end portion is arranged on the back side or the abdominal side of the extension line of the camber line of the main body portion, the flow on the wing surface is compared with the shape of the trailing edge of the conventional wing body. Wake due to peeling can be suppressed.

The wing body according to the present invention is the wing body of the present invention described above, wherein a plurality of wing bodies are arranged at equal intervals on the rotating body, and the curved surface of the trailing edge portion has no trailing edge portion. It is formed with the curvature radius which can maintain the throat (for example, throat S in embodiment) between.
According to the wing body according to the present invention, since the trailing edge does not affect the throat between the wings, it is possible to prevent the flow rate from changing due to a decrease in the throat.

  Furthermore, the rotating machine according to the present invention includes the wing body according to the present invention.

  According to the wing body and the rotating machine according to the present invention, the flow separation position from the blade surface can move rearward, and the wake from the trailing edge can be reduced, thereby reducing flow loss and flow path resistance. There is an effect that can be done.

It is the fragmentary sectional view which looked at the gas turbine in the 1st reference example of the present invention from the side. It is a figure which shows the profile of the moving blade in the 1st reference example of this invention. FIG. 3 is a partially enlarged view of the vicinity of a rear edge portion of FIG. 2. It is the elements on larger scale equivalent to FIG. 3 in the other aspect of the 1st reference example of this invention. It is a figure which shows the throat of the moving blade in the 1st reference example of this invention. It is the elements on larger scale equivalent to FIG. 3 in the 2nd reference example of this invention. It is the elements on larger scale equivalent to FIG. 3 in the other aspect of the 2nd reference example of this invention. It is the elements on larger scale equivalent to FIG. 3 in 3rd Embodiment of this invention. It is the elements on larger scale equivalent to FIG. 3 in the other aspect of 3rd Embodiment of this invention.

  Next, the wing body and the rotating machine in the first reference example of the present invention will be described with reference to the drawings. In the first reference example, a moving blade disposed at equal intervals on a rotor of a turbine section of a gas turbine will be described as an example as a blade body (hereinafter, the same applies to the second and third embodiments).

  As shown in FIG. 1, the gas turbine 100 includes a compressor 102 that generates compressed air, a combustor 103 that supplies fuel to the compressed air supplied from the compressor 102 to generate combustion gas, and a stationary blade 104. And a turbine 107 for rotating the rotor 106 to which the rotor blade 1 is attached by the combustion gas supplied from the combustor 103. In the turbine 107, a combustion gas flow path F is formed inside a cylindrical casing 108 disposed coaxially with the axis O of the rotor 106. The combustion gas flow path F is separated from the casing 108 by a cylindrical outer peripheral side end wall 110 provided on the inner peripheral side of the casing 108 on the outer peripheral side, and on the outer peripheral side of the rotor 106 on the inner peripheral side. Is separated from the rotor 106 by a cylindrical inner peripheral side end wall 111 provided in the shape of the flow path along the axis O direction having a donut cross section. In the combustion gas flow path F, a plurality of the stationary blades 104 and the moving blades 1 at each stage are radially arranged.

  FIG. 2 shows a profile of the moving blade 1 which is the blade body of the first reference example. The moving blade 1 includes a main body 4 having a back surface 2 and an abdominal surface 3. The back surface 2 is formed with a curved surface having a relatively small radius of curvature, and the abdominal surface 3 is formed with a curved surface having a larger radius of curvature than the back surface.

  Further, the moving blade 1 includes a rear edge portion 6 that connects the back surface 2 and the abdominal surface 3 of the main body portion 4 with a continuous curved surface 5 on the downstream side in the fluid flow direction (indicated by an arrow in FIG. 3). As shown in FIG. 3, the rear edge 6 has a radius of curvature that gradually decreases from either the back surface 2 or the abdominal surface 3 toward the rear end portion 7 that is the most downstream in the fluid flow direction. The radius of curvature becomes the smallest at the end portion 7, and then the radius of curvature gradually increases from the rear end portion 7 toward the other side of the back surface 2 or the abdominal surface 3 to reach either the back surface 2 or the abdominal surface 3. The rear edge portion 6 and the back surface 2 and the abdominal surface 3 are smoothly connected so that no step or corner portion is generated, and the rear end portion 7 is on the extension line 10 of the camber line 9 which is the center of the airfoil of the main body portion 4. Be placed.

  An arc 8 indicated by a broken line in FIG. 3 is a trailing edge shape of a conventional wing body, that is, a perfect circular arc (semicircle). The rear edge portion 6 of the first reference example is formed so that the radius of curvature of the curved surface 5 gradually decreases toward the rear end portion 7. Since the side is formed with the same thickness as the trailing edge of the conventional wing body, the wake can be made thin while obtaining sufficient strength. As a shape in which the radius of curvature gradually decreases toward the rear end 7, for example, an arc of an ellipse 12 whose major axis overlaps the extension line 10 of the camber line 9 may be used as shown in FIG. 4.

  As shown in FIG. 5, the rear edge 6 improves the rear edge 6 by the cross-sectional area of the throat S that is the portion where the flow path between the blades of the plurality of moving blades 1 arranged at equal intervals is the narrowest. In order to maintain the cross-sectional area of the previous throat S, the radius of curvature is gradually reduced according to the shape of the back surface 2 of the blade 1.

  Therefore, according to the moving blade 1 and the rotating machine of the first reference example described above, the radius of curvature increases as the curved surface 5 of the rear edge 6 continuous to the back surface 2 or the abdominal surface 3 of the main body 4 approaches the rear end 7. Since it is gradually reduced and thinned, the cross-sectional shape is simply a semi-circular shape like the rear edge of a conventional wing body, and the angle of the connection point between the back surface and the abdominal surface is approximately vertical while ensuring strength. Compared with the case of forming the wing, the separation position of the flow from the blade surface moves rearward, and the wake from the trailing edge 6 can be made thinner, so that the flow loss can be reduced and the efficiency can be improved.

Further, since the rear end portion 7 is disposed on the extension line 10 of the camber line 9 of the main body portion 4, the change in the radius of curvature on the abdominal surface side and the back surface side becomes equal, and the wing shape can be formed easily and smoothly.
Further, since the trailing edge 6 does not affect the throat S between the blades, it is possible to prevent the flow rate from changing due to a decrease in the throat.

  In the first reference example, the moving blade of the gas turbine has been described as an example. However, the present invention is not limited to this, and a stationary blade may be used. Moreover, it is not restricted to the blade body of a gas turbine, A compressor, a fan, a steam turbine, a windmill, and the blade body of an aircraft may be sufficient. Moreover, although the case where it applied to the airfoil from which the curvature radius of a back surface and an abdominal surface differs was demonstrated, you may apply to the object wing | blade for which the shape of the back surface and abdominal surface of an airfoil is object.

  Next, the moving blade 21 which is the blade body in the second reference example of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected and demonstrated to the same part as the moving blade 1 of a 1st reference example.

As shown in FIG. 6, the moving blade 21 of the second reference example includes a main body portion 4 having a back surface 2 and an abdominal surface 3, and a continuous curved surface 25 that connects the back surface 2 and the abdominal surface 3 downstream in the fluid flow direction. And a rear edge portion 26 connected to each other. In the curved surface 25 of the trailing edge portion 26, the rear end portion 27 which is the most downstream side in the fluid flow direction is disposed on the extension line 10 of the camber line 9.
The curved surface 25 of the rear edge portion 26 has a radius of curvature that gradually decreases from either the back surface 2 or the abdominal surface 3 toward the rear end portion 27 and becomes the smallest at the rear end portion 27. The radius of curvature gradually increases from the portion 27 toward the other of the back surface 2 or the abdominal surface 3 and reaches either the back surface 2 or the abdominal surface 3.

Here, the curved surface 25 of the rear edge portion 26 shown in FIG. 6 includes a back surface-side curved surface 25 a extending from the back surface 2 to the rear end portion 27 and a ventral surface-side curved surface 25 b extending from the abdominal surface 3 to the rear end portion 27. . The curved surface 25a and the curved surface 25b are formed such that the radius of curvature becomes smaller as they approach the rear end portion 27, but the rate of decrease of the radius of curvature is different.
More specifically, the curved surface 25a is formed so that the decreasing rate of the radius of curvature from the back surface 2 toward the rear end portion 27 is relatively constant, whereas the curved surface 25b is formed from the abdominal surface 3. The rate of decrease in the radius of curvature toward the rear end portion 27 is low at a position away from the rear end portion 27 and high near the rear end portion 27. The decreasing rate toward the rear end portion 27 of the radius of curvature near the rear end portion 27 is lower on the curved surface 25a than on the curved surface 25b.

  Like the moving blade 21 of the second reference example described above, the rate of decrease in the radius of curvature of the curved surface 25a on the back surface toward the rear end portion 27 in the trailing edge 26 and the rate of decrease in the radius of curvature of the curved surface 25b on the ventral surface. Even if they are different from each other, the cross-sectional shape is simply a semi-circular shape like the rear edge of a conventional wing body, or the connection point between the end of the dorsal edge line and the end of the ventral edge line Compared with the case where the angle is substantially vertical, the vicinity of the rear end portion 27 can be made thinner by the continuous curved surface 25, so that the separation position of the flow from the blade surface moves rearward. The wake from the edge portion 26 can be reduced, and flow loss can be reduced and efficiency can be improved.

  In the second reference example, the decreasing rate of the curvature radius of the curved surface 25a on the back surface toward the trailing end portion 27 in the vicinity of the trailing end portion 27 is lower than the decreasing rate of the curvature radius of the curved surface 25b on the ventral surface side. Although the case where it set was demonstrated, according to the conditions of throat S maintenance etc., as shown, for example in FIG. 7, the decreasing rate of the curvature radius of the curved surface 25a mentioned above and the curved surface 25b is replaced, and in the rear-end part 27 vicinity. You may make it set the decreasing rate of the curvature radius of the curved surface 25b by the side of the abdominal surface 3 toward the back end part 27 lower than the decreasing rate of the curvature radius of the curved surface 25a by the side of a back surface.

Next, the moving blade 31 which is the blade body of 3rd Embodiment of this invention is demonstrated, referring FIG. 8, FIG. In the third embodiment, the rear end portion 27 of the second reference example is offset from the extended line 10 of the camber line 9 on the back side or the abdominal side. The same parts as those in the first reference example and the second reference example described above will be described with the same reference numerals.
As shown in FIG. 8, the moving blade 31 of the third embodiment is similar to the moving blade 21 of the second reference example, on the main body portion 4 having the back surface 2 and the abdominal surface 3, and on the downstream side in the fluid flow direction. A rear edge portion 36 that connects the back surface 2 and the abdominal surface 3 with a continuous curved surface 35 is provided.

The rear end portion 37 which is the most downstream side in the fluid flow direction of the curved surface 35 of the rear edge portion 36 is disposed on the abdominal surface 3 side with respect to the extension line 10 of the camber line 9.
The curved surface 35 of the rear edge portion 36 has a radius of curvature that gradually decreases from either the back surface 2 or the abdominal surface 3 toward the rear end portion 37 and becomes the smallest at the rear end portion 37. The radius of curvature gradually increases from the portion 37 toward the other of the back surface 2 and the abdominal surface 3 and reaches either the back surface 2 or the abdominal surface 3.

  The curved surface 35 of the trailing edge 36 is similar to the above-described second reference example in that the rate of decrease in the radius of curvature of the curved surface 35 a on the back surface from the back surface 2 to the rear end portion 37 and the abdominal surface from the abdominal surface 3 to the rear end portion 37. The decreasing rate of the radius of curvature is different from that of the curved surface 35b on the side. More specifically, the curved surface 35a is formed such that the decreasing rate of the radius of curvature from the back surface 2 toward the rear end portion 37 is relatively constant, whereas the curved surface 35b is formed from the abdominal surface 3. The rate of decrease in the radius of curvature toward the rear end portion 37 is formed so as to decrease at a position away from the rear end portion 37 and to increase in the vicinity of the rear end portion 37. And the decreasing rate toward the rear end portion 37 of the radius of curvature near the rear end portion 37 is lower on the curved surface 35a than on the curved surface 35b.

  Similarly to the second reference example, the rotor blade 31 of the third embodiment has a simple semicircular cross-sectional shape like the rear edge portion of the conventional blade body, or the end portion of the back side edge line and the ventral side edge. Compared with the case where the angle of the connection point with the end of the line is formed substantially vertically, the vicinity of the rear end 27 can be formed thin by the continuous curved surface 35, so that the flow is separated from the blade surface. The position moves rearward, and the wake from the rear edge portion 36 becomes thinner, so that flow loss can be reduced and efficiency can be improved.

  In the third embodiment, the rear end portion 37 is offset toward the abdominal surface 3 with respect to the extension line 10, and the curvature of the curved surface 35 a on the back surface toward the rear end portion 37 in the vicinity of the rear end portion 37. The case where the radius reduction rate is set to be lower than the curvature radius reduction rate of the curved surface 35b on the abdominal surface side has been described, but depending on the conditions for maintaining the throat S, for example, as shown in FIG. The offset of the radius of curvature of the curved surface 35a toward the rear end portion 37 and the decrease rate of the radius of curvature of the curved surface 35b are replaced with each other by offsetting the extension line 10 toward the back surface 2 side. The decreasing rate of the radius of curvature of the curved surface 35b on the abdominal surface toward the rear end portion 37 may be set lower than the decreasing rate of the radius of curvature of the curved surface 35a on the back surface side.

1,21,31 Rotor blade 2 Rear surface 3 Abdominal surface 4 Body portion 5, 25, 35 Curved surface 6, 26, 36 Rear edge portion 7, 27, 37 Rear end portion 9 Camber line 10 Extension line 100 Gas turbine S Throat

Claims (3)

A main body having a back surface and an abdominal surface;
A rear edge portion connecting the back surface and the abdominal surface with a continuous curved surface,
The curved surface of the rear edge portion gradually decreases in radius of curvature from either the back surface or the abdominal surface toward the rear end portion located on the most downstream side in the fluid flow direction, and the curvature radius at the rear end portion. Becomes the smallest, and then gradually increases the radius of curvature from the rear end portion toward the other side of the back surface or the abdominal surface to reach either the back surface or the abdominal surface,
The wing body is characterized in that the rear end portion is disposed on the back surface side or the abdominal surface side of the extension line of the camber line of the main body portion. A plurality of wings arranged at equal intervals on the rotating body,
2. The wing body according to claim 1, wherein the curved surface of the trailing edge is formed with a radius of curvature capable of maintaining a throat between the wings when the trailing edge is not provided. 3.   A rotary machine comprising the wing body according to claim 1.

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