JP5595532B2 - 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.
A wing body according to the present invention (for example, the moving blades 1, 21, 31 in the embodiment) is a wing body that is arranged in a plurality of positions on the rotating body at equal intervals, and has a back surface (for example, the back surface 2 in the embodiment) and an abdominal surface. The body part (for example, the body part 4 in the embodiment) having (for example, the abdominal surface 3 in the embodiment) and the back surface and the abdominal surface are continuous curved surfaces (for example, the curved surfaces 5, 25, 35 in the embodiment). A rear edge portion (for example, 6, 26, 36 in the embodiment) to be connected, and the curved surface of the rear edge portion is located on the most downstream side in the fluid flow direction from either the back surface or the abdominal surface The radius of curvature gradually decreases toward an end portion (for example, the rear end portions 7, 27, and 37 in the embodiment), and the curvature radius becomes the smallest at the rear end portion. To either side of the stomach Reaches the other one of the back or the belly gradually radius of curvature is increased, the trailing portion is disposed on an extension of the camber line of the main body portion, the curved surface of the trailing edge, the trailing edge throat (e.g., the throat S in the embodiment) between the blades when no that are formed in a sustainable radius of curvature.
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.

  Further, by arranging the rear end portion on the extension line of the camber line of the main body portion, the curvature radius changes on the abdominal surface side and the back surface side become equal, and the wing shape can be formed easily and smoothly.

Furthermore , since the trailing edge does not affect the throat between the blades, 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. Further, the wing shape can be easily and smoothly formed.

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

  Next, the wing body and the rotary machine according to the first embodiment of the present invention will be described with reference to the drawings. In the first embodiment, 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 this embodiment. 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 present embodiment is formed so that the radius of curvature of the curved surface 5 gradually decreases toward the rear end portion 7, so that the rear edge portion 6 extends narrower downstream than the arc 8. Further, the base side of the rear edge portion 6 is Since it is formed with the same thickness as the trailing edge of a 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 rotary machine of the above-described embodiment, the curvature radius gradually increases as the curved surface 5 of the rear edge portion 6 continuous with the back surface 2 or the abdominal surface 3 of the main body portion 4 approaches the rear end portion 7. Since the thickness is reduced and the thickness is reduced, the cross-sectional shape is simply a semi-circular shape and the angle of the connection point between the back and abdominal surfaces is made almost vertical, as in the rear edge of a conventional wing body, while ensuring strength. Compared to the case, the separation position of the flow from the blade surface moves rearward, and the wake from the trailing edge portion 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 above embodiment, 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 a blade body in the second embodiment 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 1st Embodiment.

As shown in FIG. 6, the moving blade 21 according to the second embodiment includes a main body 4 having a back surface 2 and an abdominal surface 3, and a continuous curved surface 25 on the back surface 2 and the abdominal surface 3 on the downstream side 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 embodiment 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 portion 26 and the rate of decrease in the radius of curvature of the curved surface 25b on the ventral surface side. 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 embodiment, the rate of decrease in the radius of curvature of the curved surface 25a on the back side toward the rear end 27 in the vicinity of the rear end 27 is lower than the rate of decrease in the radius of curvature of the curved surface 25b on the ventral surface. 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, a moving blade 31 that is a blade body of a reference example of the present invention will be described with reference to FIGS. In this reference example, the rear end portion 27 of the second embodiment is offset from the extended line 10 of the camber line 9 on the back side or the abdominal side. The same portions as those in the first embodiment and the second embodiment described above are denoted by the same reference numerals for description.
As shown in FIG. 8, the moving blade 31 of this reference example is similar to the moving blade 21 of the second embodiment in that the main body portion 4 having the back surface 2 and the abdominal surface 3 and the back surface 2 on the downstream side in the fluid flow direction. And a rear edge 36 that connects the abdominal surface 3 with a continuous curved surface 35.

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 rear edge portion 36 is similar to the second embodiment described above in that the rate of decrease in the radius of curvature of the curved surface 35a 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 are similar. 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.

  Also in the moving blade 31 of this reference example, as in the second embodiment, the cross-sectional shape is simply a semicircular shape like the rear edge portion of the conventional blade body, or the end of the back side edge line and the ventral side edge line Compared to the case where the angle of the connection point with the end portion is formed substantially perpendicularly, the vicinity of the rear end portion 27 can be formed thin by the continuous curved surface 35, so that the separation position of the flow from the blade surface is Moving backward, the wake from the trailing edge 36 becomes thinner, and flow loss can be reduced and efficiency can be improved.

  In the above reference example, the rear end portion 37 is offset to the abdominal surface 3 side with respect to the extension line 10, and the radius of curvature of the curved surface 35 a on the back side toward the rear end portion 37 in the vicinity of the rear end portion 37. The case where the reduction rate is set lower than the reduction rate of the radius of curvature of the curved surface 35b on the abdominal surface side has been described. However, depending on the conditions for maintaining the throat S, for example, as shown in FIG. 10 is offset to the back surface 2 side, and the decrease rate of the curvature radius of the curved surface 35a toward the rear end portion 37 and the decrease rate of the curvature radius of the curved surface 35b described above are interchanged, and the rear portion in the vicinity of the rear end portion 37 is replaced. You may make it set the decreasing rate of the curvature radius of the curved surface 35b of the abdominal surface toward the edge part 37 lower than the decreasing rate of the curvature radius of the curved surface 35a of the back 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 (2)

A plurality of wings arranged at equal intervals on the rotating body,
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 rear end portion is disposed on an extension line of the camber line of the main body portion ,
The curved surface of the trailing edge is a wing body formed with a radius of curvature capable of maintaining a throat between the blades when the trailing edge is not provided. A rotating machine comprising the wing body according to claim 1 .

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