Cooling system for a main body used in a gas stream

[0002] This is a division of application Ser. No. 08/862,301, filed on May 23, 1997, now U.S. Pat. No. 6,092,982, which is incorporated herein by reference.

[0003] The present invention relates to a structure with elements including a main body used in a gas stream, and especially relates to the main body including a plurality of fluid passages used in the gas stream.

[0004] In a gas turbine, if the gas temperature is high during a first stage of the turbine, the efficiency for generating electric power increases. However, in order to raise the gas temperature for the first stage of the turbine, the heat-durability of the turbine blade and turbine nozzle should also be increased. As a method for raising the heat-durability of the gas turbine, film cooling by fluid on the blade surface is well known. FIG. 1 is a schematic diagram of the turbine blade of the gas turbine according to the prior art. The turbine blade consists of a main body 1 of the blade and a base 2 to attach the main body to a rotor (not shown in FIG. 1). FIG. 2 is a sectional plan of line K—K of FIG. 1. FIG. 3 is a sectional plan of the J—J line of FIG. 1. As shown in FIG. 2 and FIG. 3, three coolant passages 3a, 3b, 3care formed in the base 2 and the main body 1. The three coolant passages are connected to a supply source of cooling fluid. The cooling fluid in the coolant passage 3a, 3b, 3cexecutes convective cooling through the base 2 and the main body 1. When the cooling fluid flows through the coolant passages 3a, 3b, it flows out through a plurality of outlets 8 on the leading edge 4, side wall 5, other side wall 6, tip 7. The cooling fluid in the coolant passage 3cflows out through outlets 10 on the trailing edge 9.

[0005] The outlet of coolant passage is normally formed as an ellipse. FIG. 4 is a schematic diagram of the outlet of the coolant passage on the blade surface according to the prior art. FIG. 5 is a sectional plan of line L—L of FIG. 4. As shown in FIG. 4 and FIG. 5, in the outlet 8 passing through the side wall 5 and the other side wall 6, the center line 12 of the outlet of the coolant passage is inclined in the direction of the gas stream 11 on the surface of the wall 5 (6). The cooling fluid flowing from the outlet 8 is mixed with the gas stream 11 flowing over the surface at high speed, and cools the surface by forming a film-like layer over it. As a method for setting the outlet on the surface, plural lines of the outlets 8 perpendicular to the direction of the gas stream 11 may be set as shown in FIG. 6 and FIG. 7. In order to supplement the outlets 8 on the upstream side, the outlets 8 on the downstream side, whose position is different from the position of the outlets on the upstream side, are set as shown in FIG. 8. Furthermore, in order to strengthen the film cooling effectiveness of the spread of the fluid, the diameter of the outlet 13 is gradually increased as it reaches the surface as shown in FIG. 9A and FIG. 9B. Alternatively, as shown in FIG. 10, the outlet 13 is opened at fixed intervals as it reaches the surface, thus resembling a staircase.

[0006] However, in the film cooling method in which the center line 12 of the coolant passage is inclined in the direction of the stream, the following problem occurs.

[0007] The cooling fluid flowing from the outlet 8 has a high Kinetic energy stream that crosses the direction of the gas stream flowing along the surface. Therefore, as shown in FIG. 11, a separation of the coolant as the cooling fluid flows up in a columnar shape occurs. As a result, the gas stream 11 is divided by a pillar 14 of cooling fluid flown from the outlet 8 and rolled up in the downstream area of the pillar 14. This makes it is difficult for the fluid film to cover the surface 5 (6) and therefore film cooling effectiveness reduces. Furthermore, when the outlet is shaped as shown in FIG. 9B and FIG. 10, the fluid film covers only 70% of the surface interval between neighboring outlets. In addition, the pressure of the fluid flowing from the outlet is low because of the wide outlet 13. Therefore, in the downstream area of the outlet 8 on the surface 5 (6), the gas stream 11 mixes with the cooling fluid 14, and the film cooling effectiveness is low.

[0008] On the other hand, according to the prior method shown in FIGS. 12A and 12B, the direction of the coolant passage is inclined in a direction different from the direction of the gas stream along the surface (i.e., the “lateral direction”). In this method, the fluid diffuses laterally in the direction of the gas stream. In short, the flown fluid diffuses only along the lateral area in the direction of the gas stream. The film cooling effectiveness of the fluid for downstream area is therefore low.

[0009] As another prior method shown in FIGS. 13A and 13B, the outlet is shaped as a diffusion type in addition to the specific feature of FIGS. 12A and 12B. In this method, the center line of the diffusion part is inclined in the lateral direction similar to the center line of the outlet of the coolant passage. Therefore, the film cooling effectiveness of the fluid over the downstream area is low in the same way as shown in FIGS. 12A and 12B.

[0010] It is an object of the present invention to provide a structure with elements that are able to suppress the roll up of the gas stream for the fluid down stream of each outlet on surface of the main body.

[0011] It is another object of the present invention to provide a structure with elements, which are able to uniformly spread the cooling fluid over a wide area of the surface as a fluid film.

[0012] According to the present invention, there is provided a structure with elements including a main body of the elements used in the gas stream and a plurality of fluid passages. Each outlet opens onto the surface of the main body and fluid flows from each outlet through the passage to cover the surface as a fluid film, wherein the plurality of fluid passages, comprising: a first fluid passage, from which fluid flows in the direction of the gas stream on the surface, and a second fluid passage, adjoining the first fluid passage from which fluid flows against the gas stream to suppress the roll up of the gas stream caused by the fluid downstream of each outlet.

[0013] Further in accordance with the present invention, there is provided a structure with elements, including a main body of the element used in the gas stream and a plurality of fluid passages. The fluid passages have outlets which opens onto the surface of the main body through which the fluid flows, covering the surface in the form of a film. The plurality of fluid passages, comprise: a first fluid passage, from which fluid flows along a predetermined direction different from the direction of the gas stream on the surface, and a second fluid passage adjoining the first fluid passages, from which fluid flows against the gas stream to suppress roll up of the gas stream caused by the fluid downstream of each outlet.

[0014] Further in accordance with the present invention, there is provided a structure with elements, including a main body of the element used the gas stream and a plurality of fluid passages, each outlet of which opens onto the surface of the main body. Fluid flows from each outlet through the passage to cover the surface as a fluid film. The plurality of fluid passages are configured so that a center line of each fluid passage is inclined in the direction of the gas stream flowing on the surface.

[0015] Further in accordance with the present invention, there is provided structure with elements, including a main body of the element used in the gas stream and a plurality of fluid passages, each outlet of which opens onto the surface of the main body. Fluid flows from each outlet through the passage to cover the surface as a fluid film. The plurality of fluid passages are configured so that a center line of each fluid passage is inclined in the direction of the gas stream on the surface. The fluid passages include an inner wall forming the fluid passage toward the outlet on the surface of the main body. The inner wall is inclined toward the upstream side of the edge of the outlet from a predetermined inner position in the direction of the inner wall to the upstream side of the edge of the outlet on the surface.

[0016] Further in accordance with the present invention, there is provided a structure with elements, including a main body of the element used in the gas stream and a plurality of fluid passages, each outlet of which opens onto the surface of the main body. Fluid flows from the each outlet through the passage to cover the surface as a fluid film. The plurality of fluid passages comprising a diffusion outlet partially extended from each outlet on the surface. The diffusion outlet is shaped asymmetrically based on the direction of the fluid stream from the each outlet. One edge of the diffusion outlet is perpendicular to the direction of the gas stream.

[0017] FIG. 1 is a schematic diagram of the blade of a gas turbine according to the prior art.

[0018] FIG. 2 is a sectional plan of line K—K of FIG. 1.

[0019] FIG. 3 is a sectional plan of line J—J of FIG. 1.

[0020] FIG. 4 is a schematic diagram of the first example of the outlet of the coolant passage on the surface of the blade according to the prior art.

[0021] FIG. 5 is a sectional plan of line L—L of FIG. 4.

[0022] FIG. 6 is a schematic diagram of the second example of the coolant passage on the surface of the blade according to the prior art.

[0023] FIG. 7 is a schematic diagram of the third example of the coolant passage on the surface of the blade according to the prior art.

[0024] FIG. 8 is a schematic diagram of the fourth example of the coolant passage on the surface of the blade according to the prior art.

[0025] FIG. 9A is a schematic diagram of the fifth example of the coolant passage on the surface of the blade according to the prior art.

[0026] FIG. 9B is a sectional plan of line N—N of FIG. 9A.

[0027] FIG. 10 is a sectional plan of another construction of the fifth example.

[0028] FIG. 11 is a schematic diagram showing the problem of the outlet of the coolant passage according to the prior art.

[0029] FIG. 12A is a schematic diagram of the sixth example of the coolant passage on the surface of the blade according to the prior art.

[0030] FIG. 12B is a sectional plan of line T—T of FIG. 12A.

[0031] FIG. 13A is a schematic diagram of seventh example of the coolant passage on the surface of the brade according to the prior art.

[0032] FIG. 13B is a sectional plan of line U—U of FIG. 13A.

[0033] FIG. 14A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a first embodiment of the present invention.

[0034] FIG. 14B is a sectional plan of line A—A of FIG. 14A.

[0035] FIG. 15A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a second embodiment of the present invention.

[0036] FIG. 15B is a sectional plan of line B—B of FIG. 15A.

[0037] FIG. 16A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a third embodiment of the present invention.

[0038] FIG. 16B is a sectional plan of line C—C of FIG. 16A.

[0039] FIG. 17A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a fourth embodiment of the present invention.

[0040] FIG. 17B is a sectional plan of line M—M of FIG. 17A.

[0041] FIG. 18A is a schematic diagram of outlet of coolant passage on surface of the blade according to a fifth embodiment of the present invention.

[0042] FIG. 18B is a sectional plan of line D—D of FIG. 18A.

[0043] FIG. 19A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a sixth embodiment of the present invention.

[0044] FIG. 19B is a sectional plan of line E—E of FIG. 19A.

[0045] FIG. 20A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a seventh embodiment of the present invention.

[0046] FIG. 20B is a sectional plan of line M—M of FIG. 20A.

[0047] FIG. 21A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to an eighth embodiment of the present invention.

[0048] FIG. 21B is a sectional plan of line N—N of FIG. 21A.

[0049] FIG. 22A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a ninth embodiment of the present invention.

[0050] FIG. 22B is a sectional plan of line O—O of FIG. 22A.

[0051] FIGS. 23A and 23B are schematic diagrams of the turbine blade including the coolant passages according to the first embodiment.

[0052] FIG. 24 is graph comparing the cooling efficiencies of the structures embodied in the present invention and the prior art.

[0053] FIG. 25A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a tenth embodiment of the present invention.

[0054] FIG. 25B is a sectional plan of line F—F of FIG. 25A.

[0055] FIG. 26A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to an eleventh embodiment of the present invention.

[0056] FIG. 26B is a sectional plan of line G—G of FIG. 26A.

[0057] FIG. 27A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a twelfth embodiment of the present invention.

[0058] FIG. 27B is a sectional plan of line H—H of FIG. 27A.

[0059] FIG. 28A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a thirteenth embodiment of the present invention.

[0060] FIG. 28B is a sectional plan of line I—I of FIG. 28A.

[0061] FIG. 29 is a schematic diagram of the turbine blade including the coolant passage according to the thirteenth embodiment.

[0062] FIG. 30A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a fourteenth embodiment of the present invention.

[0063] FIG. 30B is a sectional plan of line A—A line of FIG. 30A.

[0064] FIG. 31A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a fifteenth embodiment of the present invention.

[0065] FIG. 31B is a sectional plan of line B—B of FIG. 31A.

[0066] FIG. 32A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a sixteenth embodiment of the present invention.

[0067] FIG. 32B is a sectional plan of line C—C of FIG. 32A.

[0068] FIG. 33A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a seventeenth embodiment of the present invention.

[0069] FIG. 33B is a sectional plan of line D—D of FIG. 33A.

[0070] FIG. 34A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to an eighteenth embodiment of the present invention.

[0071] FIG. 34B is a sectional plan of line E—E of FIG. 34A.

[0072] FIG. 35A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a nineteenth embodiment of the present invention.

[0073] FIG. 35B is a sectional plan of line F—F of FIG. 35A.

[0074] FIG. 36A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a twentieth embodiment of the present invention.

[0075] FIG. 36B is a sectional plan of line G—G of FIG. 36A.

[0076] FIG. 37A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a twenty-first embodiment of the present invention.

[0077] FIG. 37B is a sectional plan of line H—H of FIG. 37A.

[0078] FIG. 38A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a twenty-second embodiment of the present invention.

[0079] FIG. 38B is a sectional plan of line I—I of FIG. 38A.

[0080] FIG. 39A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a twenty-third embodiment of the present invention.

[0081] FIG. 39B is a sectional plan of line J—J of FIG. 39A.

[0082] FIG. 40A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a twenty-fourth embodiment of the present invention.

[0083] FIG. 40B is a sectional plan of line K—K of FIG. 40A.

[0084] FIG. 41A is a schematic diagram of the outlet of the coolant passage on the surface of the blade according to a twenty-fifth embodiment of the present invention.

[0085] FIG. 41B is a sectional plan of line L—L of FIG. 41A.

[0086] FIG. 42 is a schematic diagram of the turbine blade including the coolant passage according to the fourteenth embodiment.

[0087] FIG. 14A is a plan view of an outlet of a coolant passage on the surface of the turbine blade according to a first embodiment of the present invention. FIG. 14B is a sectional plan of line A—A of FIG. 14A. In FIGS. 14A and 14B, material 21 represents a main body such as the turbine blade or the turbine nozzle. The high temperature gas stream 23 flows over one surface 22 of the main body 21. In the main body 21, a plurality of main passages (first outlet 27 of coolant passage 29) 25 and a plurality of subpassages (second outlet 28 of coolant passage 30) 26 are set. Each section of the main passage 25 and the sub passage 26 is circularly shaped. The first outlet 27 and the second outlet 28 are mutually located along a direction perpendicular to the direction of the gas stream 23 on the surface 22. The cooling fluid flows from the first outlet 27 through the first coolant passage 29 and from the second outlet 28 through the second coolant passage 30. A center line 31 of the first coolant passage 29 is inclined to the downstream side in relation to the direction of the gas stream 23. A center line 32 of the second coolant passage 30 is inclined to the upstream side in relation to the direction of the gas stream 23. The first coolant passage 29 and the second coolant passage 30 are connected to a supply section of the cooling fluid (not shown). Preferably, the section size of the first outlet 27 is larger than the section size of the second outlet 28.

[0088] Preferably, an inclination angle of the first coolant passage 29 facing downstream is smaller than an inclination angle of the second coolant passage 30 facing upstream. Furthermore, the spaces between the first outlets 27, whose direction is perpendicular to the direction of the gas stream 23, are preferably less than three to five times the diameter of the circular of the passage 25. In the above-mentioned structure, the cooling fluid flows from the first outlet 27 to the downstream side in relation to the direction of the gas stream 23. The cooling fluid flows from the second outlet 28 to the upstream side on the surface 22. In this case, the cooling fluid flowing from the second outlet 28 collides with the gas stream 23 passing along side of the first outlet 27. Therefore, the gas stream 23 does not roll up the pillar of the cooling fluid flowing from the first outlet 27. In short, the pillar of cooling fluid easily settles on the downstream side and the cooling fluid film spreads widely along the downstream area. Furthermore, the cooling fluid from the second outlet 28 mixes with the gas stream 23 and the temperature of the gas stream drops. The low temperature gas stream flows on the space between the neighboring first outlets 27. Therefore, cooling for the space between neighboring first outlets 27 is executed and the surface temperature distribution in the direction perpendicular to the direction of the gas stream is made uniform.

[0089] FIG. 15A is a plan of an outlet of a coolant passage on the surface of the turbine according to a second embodiment of the present invention. FIG. 15B is a sectional plan of line B—B of FIG. 15A. In structure of the second embodiment in FIGS. 15A and 15B, two second outlets 28 are located on both sides of the first outlet 27. The two center lines of the two second outlets 28 mutually cross on the upstream side of the first outlet 27 based on the direction of the gas stream 23. The direction of this intersecting flow opposes the direction of the gas stream, which is rolled up. In the second embodiment, the efficiency of the cooling fluid from the second outlet increases. In short, the gas stream 23 roll-up of the cooling fluid flowing from the first outlet 27 is avoided. The cooling fluid film certainly spreads on the downstream side from the first outlet 27.

[0090] FIG. 16A is a plan of an outlet of a coolant passage on the surface of the turbine blade according to a third embodiment of the present invention. FIG. 16B is a sectional plan of line C—C of FIG. 16A. In the structure of the third embodiment, the second outlets 28 are respectively arranged downstream from the arrangement line of the first outlets 27 in addition to the structure of the first embodiment. As in the first embodiment, the cooling fluid flowing from the second outlet 28 collides with the gas stream 23 passing along side of the first outlet 27. Therefore, the gas stream 23 roll-up of the pillar of the cooling fluid flowing from the first outlet 27 does not occure. The cooling fluid film thus widely spreads over the downstream area. Furthermore, the cooling fluid from the second outlet 28 mixes with the gas stream 23 and the temperature of the gas stream drops. The low temperature gas stream flows over the space between neighboring first outlets 27. Cooling of the space between the neighboring first outlets 27 is thus executed.

[0091] FIG. 17A is a plan of an outlet of a coolant passage on the surface of the turbine blade according to a fourth embodiment of the present invention. FIG. 17B is a sectional plan of line M—M of FIG. 17A. In the structure of the fourth embodiment, two second outlets 28 (26) are located on both sides of the first outlet 27 (25). Two center lines 32 of the two second outlets 28 are parallel to the center line 31 of the first outlet 27. The cooling fluid flowing from the second outlets 28 obstructs the gas stream 23 passing on both sides of the first outlet 27. As a result, the gas stream 23 roll-up the fluid flowing from the first outlet 27 is avoided. Accordingly, the pillar of the cooling fluid easily settles on the downstream area and the cooling fluid film spreads widely and uniformly on the downstream area.

[0092] In the four above-mentioned embodiments, the center line 31 of the first coolant passage 25 is inclined to the downstream side relative to the direction of the gas stream 23, and the center line 32 of the second coolant passage is inclined to the upstream side or the downstream side. However, the center line 31 of the first coolant passage 25 may be inclined to the upstream side and the center line 32 of the second coolant passage may be inclined to the downstream side or the upstream side. In this case, the cooling fluid flowing from the first outlet collides with the gas stream and the cooling fluid flowing from the second outlet obstructs passage of the gas stream. Therefore, the gas stream roll-up of the cooling fluid is avoided. Furthermore, the temperature of the gas stream drops and this gas stream flows downstream from the first outlet. The fluid film therefore settles uniformly on the downstream side.

[0093] FIG. 18A is a plan of an outlet of a coolant passage on the surface of the turbine blade according to a fifth embodiment of the present invention. FIG. 18B is a sectional plan of line D—D of FIG. 18A. In the fifth embodiment, the second outlet 28 is located between the neighboring two first outlets 27 and a center line 32 of the second coolant passage 26 is inclined along a direction perpendicular to the direction of the gas stream 23. The cooling fluid flowing from the outlet 28 obstructs the gas stream 23 passing on both sides of the first outlets 27. As a result, the gas stream 23 roll- up of the cooling fluid flowing from the first outlet 27 is avoided. Accordingly, the pillar of the cooling fluid easily settles on the downstream side and the cooling fluid film spreads widely on the downstream area.

[0094] FIG. 19A is a plan of the outlet of the coolant passage on the surface of the turbine blade according to a sixth embodiment of the present invention. FIG. 19B is a sectional plan of line E—E of FIG. 19A. In the sixth embodiment, two second outlets 28 (26) are located on both sides of the first outlet 27 (25). The two center lines of the two second coolant passages 26 intersects at a position above the first outlet 27. The upper position departs from the first outlet 27 after a predetermined distance. Therefore, cooling fluid flowing from the outlet 28 obstructs the gas stream 23 passing on both side of the first outlet 27. As a result, the gas stream 23 roll-up of the cooling fluid flowing from the first outlet 27 is avoided. Accordingly, the pillar of the cooling fluid easily settles on the downstream side and the cooling fluid film spreads widely on the downstream area.

[0095] FIG. 20A is a plan of a coolant passage on the surface of the turbine blade according to a seventh embodiment of the present invention. FIG. 20B is a sectional plan of line M—M of FIG. 20A. In the seventh embodiment, the first coolant passage 50 is inclined in the lateral direction of the downstream side of the gas stream 23. The second coolant passage 60 is inclined to the upstream side on the surface 22. In the structure of the seventh embodiment, the cooling fluid flows from the first outlet 52 toward the lateral direction of the downstream side. On the other hand, the cooling fluid flows from the second outlet 62 toward the upstream side. In this case, the cooling fluid flowing from the second outlet 62 suppresses the roll-up of the gas stream 23 of the cooling fluid flowing from the first outlet 52. In addition, the cooling fluid flowing from the second outlet 62 mixes with the gas stream 23. Therefore, the cooling fluid film uniformly spreads in the lateral direction on the surface 22. Furthermore, the cooling fluid flows from the first outlet 52 in the lateral direction of the downstream side. Therefore, the cooling fluid film widely spreads toward the lateral direction of the downstream side.

[0096] FIG. 21A is a plan of a coolant passage on the surface of the turbine blade according to an eighth embodiment of the present invention. FIG. 21B is a sectional plan of line N—N of FIG. 21A. In the eighth embodiment, the first coolant passage 50 is inclined to the lateral direction of the downstream side of the gas stream 23. The second coolant passage 60 is inclined to the lateral direction of the upstream side. The direction of the center line 54 of the first coolant passage 50 is parallel to the direction of the center line 64 of the second coolant passage 60 on the surface 22. In the structure of the eighth embodiment, the cooling fluid flows from the first outlet 52 toward the lateral direction of the downstream side. On the other hand, the cooling fluid flows from the second outlet 62 toward the lateral direction of the upstream side. In this case, the cooling fluid flowing from the second outlet 62 suppresses the roll-up of the gas stream 23 of the cooling fluid flowing from the first outlet 52. In addition, the cooling fluid flowing from the second outlet 62 mixes with the gas stream 23. Therefore, the cooling fluid film is uniformly spread in the lateral direction on the surface 22. Furthermore, the cooling fluid flown from the first outlet 52 flows from the first outlet 52 toward the lateral direction of the downstream side. Therefore, the cooling fluid film widely spreads in the lateral direction of the downstream side.

[0097] FIG. 22A is a plan of a coolant passage on the surface of the turbine brade according to ninth embodiment of the present invention. FIG. 22B is a sectional plan of line O—O of FIG. 22A. In the ninth embodiment, the first coolant passage 50 is inclined in the lateral direction of the downstream side of the gas stream 23. The second coolant passage 60 is inclined in the lateral direction of the upstream side. Furthermore, the center line 54 of the first coolant passage 50 intersects the center line 64 of the second coolant passage 60 at more than 90 degrees. In the structure of the ninth embodiment, the cooling fluid flows from the first outlet 52 in the lateral direction of the downstream side. On the other hand, the cooling fluid flows from the second outlet 62 in the lateral direction of the upstream side. In this case, the cooling fluid flowing from the second outlet 62 suppresses the roll-up of the gas stream 23 of the cooling fluid flowing from the first outlet 52. In addition, the cooling fluid flowing from the second outlet 62 mixes with the gas stream 23. Therefore, the cooling fluid film spreads uniformly in the lateral direction on the surface 22. Furthermore, the cooling fluid flows from the first outlet 52 in the lateral direction of the downstream side. Therefore, the cooling fluid film widely spreads in the lateral direction of the downstream side.

[0098] FIGS. 23A and 23B are schematic diagrams of the turbine blade including the coolant passages to which the first embodiment is applied. As shown in FIG. 23B, the turbine blade consists of a main body 41 of the blade and a base 42 to connect the main body 41 to a rotor (not shown). A plurality of coolant passages are formed in the base 42 and the main body 41. Each entrance of the coolant passage leads to a path of cooling fluid in the rotor. The cooling fluid flows through the coolant passage in the base 42 and the main body 41 and flows out from each outlet 46, 47. In FIG. 23B, the first outlet 46 and the second outlet 47 are mutually arranged along a direction perpendicular to the direction of the gas stream on the leading edge 43, body wall 44 and other wall 45. In this case, a center line of the first outlet 46 is inclined to the downstream side of the gas flow. A center line of the second outlet 47 is inclined to the upstream side. Referring to FIG. 23A, within each group of first outlets 46 or second outlets 47, the outlets 46 or 47 are located at approximately the same height above base 42. Preferably, the size of the first outlet 46 is equal to or larger than size of the second outlet 47.

[0099] FIG. 24 is a graph comparing the cooling efficiencies of the structures embodied in the present invention and the prior art. In FIG. 24, X1 represents the film cooling efficiency of the outlet of the prior art shown in FIG. 7; X2 represents the film cooling efficiency of the outlet of the prior art shown in FIG. 8; X3 represents the film cooling efficiency of the outlet of the present invention shown in FIGS. 15A and 15B. According to the graph, the cooling efficiency of the present invention is greater in comparison with the prior art.

[0100] FIG. 25A is a plan of an outlet of a coolant passage on the surface of the blade according to a tenth embodiment of the present invention. FIG. 25B is a sectional plan of line F—F of FIG. 25A. In the tenth embodiment, a plurality of one kind of outlet 52 (coolant passage 51) is set in the turbine blade 21f. One entrance of the coolant passage 51 is connected to supply section 53 of cooling fluid. Another entrance of the coolant passage 51 is opened as the outlet 52 on the surface 22. A center line 54 of the coolant passage 51 is inclined toward the upstream side of the gas flow. The shape of the outlet 52 may be circular or rectangular. The inclined angle of the coolant passage 51 is determined by the condition of the gas stream and the curvature ratio of the surface 22. In the structure of the tenth embodiment, the cooling fluid flowing from the outlet 52 collides with the gas stream 23. Therefore, the gas stream 23 does not roll up the cooling fluid in the downstream area. The gas stream 23 mixed with the cooling fluid flows, pushing the remaining cooling fluid downstream along the surface. Therefore, the cooling fluid film is well formed on the downstream area of the outlet 52.

[0101] FIG. 26A is a plan of an outlet of a coolant passage on the surface of the blade according to an eleventh embodiment of the present invention. FIG. 26B is a sectional plan of line G—G of FIG. 26A. In the eleventh embodiment, a diffusion outlet 56 is formed on the outlet 55. As shown in FIG. 26B, the diffusion outlet 56 occupies part of the downstream side of the inner wall of the coolant passage 51a. The downstream side of the inner wall from the surface 22 to predetermined length along a direction of the coolant passage is inclined in the downstream direction. In this structure, the quantity of cooling fluid flowing along arrow 54 (upstream side) is larger than the quantity of cooling fluid flowing along arrow 57 (downstream side). In the area where the movement of the gas stream is rapid such as the downstream area of the stagnation region, the quantity of the cooling fluid to the downstream area is preferably smaller than the quantity of the cooling fluid to the upstream area. This structure is suitable for the area on which gas stream flows with accelerated speed.

[0102] FIG. 27A is a plan of an outlet of a coolant passage on the surface of the blade according to a twelfth embodiment of the present invention. FIG. 27B is a sectional plan of line H—H of FIG. 27A. In the twelfth embodiment, in addition to structure of the eleventh embodiment, a diffusion outlet 58 is formed on the upstream side of the outlet 52b. As shown in FIG. 27B, the diffusing outlet 58 occupies part of the upstream side of the inner wall of the coolant passage 51b. In short, the upstream side of the inner wall is inclined in the upstream direction from the surface 22 to a predetermined length along a direction of the coolant passage. In this structure, in addition to the effect of the eleventh embodiment, the cooling fluid flows to the upstream side along an arrow 59 and the quantity of the cooling fluid flowing to the upstream side increases. Therefore, the mix between the gas stream 23 and the cooling fluid is high for areas where the movement of the gas stream is rapid. The inclination of the angle of the diffusion outlets 56, 58 is determined by the condition of the gas stream and curvature ratio of the surface 22.

[0103] FIG. 28A is a plan of an outlet of a coolant passage on the surface of the blade according to a thirteenth embodiment of the present invention. FIG. 28B is a sectional plan of line I—I of FIG. 28A. In the thirteenth embodiment, a center line 54 of the coolant passage 51C is inclined to the downstream side on the surface 22. A diffusion outlet 60 is formed on the upstream side of the outlet 52C. As shown in FIG. 28B, the diffusing outlet 60 occupies part of the upstream side of the inner wall of the coolant passage 51C. In short, the upstream side of the inner wall is inclined in the upstream direction from the surface 22 to predetermined length along the direction of the coolant passage. In this structure, a part of the cooling fluid flows along the arrow 61 to the upstream side. In addition, the cooling fluid flows along the arrow 54 to the downstream side. Film coverage is widely spread on the downstream side of the outlet 52C. The inclination of the angle of the diffusion outlet 60 is determined by the condition of the gas stream and the curvature ratio of the surface 22.

[0104] FIG. 29 is a schematic diagram of the turbine blade including the coolant passage according to the thirteenth embodiment. In FIG. 29, the outlet 51C of FIG. 28A is applied to the front wall 43 of the turbine blade 41.

[0105] FIG. 30A is a plan of an outlet of a coolant passage on the surface of the blade according to a fourteenth embodiment of the present invention. FIG. 30B is a sectional plan of line A—A of FIG. 30A. In the fourteenth embodiment, a plurality of the outlets 52 of the coolant passage 51 are arranged in a direction perpendicular to the gas flow 23 ( only one outlet 52 is shown in FIG. 30A). A center line 54 of the coolant passage 51 is inclined to the downstream side of the gas flow 23. A diffusion outlet 55 is formed on the outlet 52. The shape of the diffusing outlet 55 is inclined to laterally and vertically in the direction of the gas flow. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 to the downstream side. A part of the cooling fluid flows from the diffusion outlet 55 to the lateral direction. That part of the cooling fluid collides with the gas stream from a direction perpendicular to the gas flow 23. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is distributed uniformly on the downstream area.

[0106] FIG. 31A is a plan of an outlet of a coolant passage on the surface of the blade according to a fifteenth embodiment of the present invention. FIG. 31B is a sectional plan of line B—B of FIG. 31A. In the fifteenth embodiment, the center line 54 of the coolant passage 51 is inclined in lateral direction of the downstream side of the gas flow. The diffusing outlet 55 is formed on the outlet 52. The shape of the diffusion outlet 55 is inclined vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 to the downstream side. A part of the cooling fluid flows from the diffusion outlet 55 to the downstream side. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area, and the temperature is distributed uniformly on the downstream area.

[0107] FIG. 32A is a plan of an outlet of a coolant passage on the surface of the blade according to a sixteenth embodiment of the present invention. FIG. 32B is a sectional plan of line C—C of FIG. 32A. In the sixteenth embodiment, the center line 54 of the coolant passage 51 is inclined in a lateral direction of the downstream side of the gas flow 23. The diffusion outlet 55 is formed on the outlet 52. The shape of the diffusion outlet 55 inclined laterally and vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 to the downstream side. A part of the cooling fluid flows from the diffusion outlet 55 to the downstream side. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is uniformly distributed on the downstream area.

[0108] FIG. 33A is a plan of an outlet of a coolant passage on the surface of the blade according to a seventeenth embodiment of the present invention. FIG. 33B is a sectional plan of line D—D of FIG. 33A. In the seventeenth embodiment, the center line 54 of the coolant passage 51 is inclined in the upstream side of the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusing outlet 55 is inclined laterally and vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 to the upstream side. A part of the cooling fluid flows from the diffusing outlet 55 in the lateral direction. This part of the cooling fluid collides with the gas stream from a direction perpendicular to the gas flow 23. Therefore, the gas stream roll-up the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is distributed uniformly on the downstream area.

[0109] FIG. 34A is a plan of an outlet of a coolant passage on the surface of the blade according to an eighteenth embodiment of the present invention. FIG. 34B is a sectional plan of line E—E of FIG. 34A. In the eighteenth embodiment, the center line 54 of the coolant passage 51 is inclined laterally in the direction of the upstream side in relation to the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusion outlet 55 is inclined vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 in the lateral direction of the upstream side. A part of the cooling fluid flows from the diffusion outlet 55 to the upstream side. This part of the cooling fluid collides with the gas stream. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is uniformly distributed on the downstream area.

[0110] FIG. 35A is a plan of an outlet of a coolant passage on the surface of the blade according to a nineteenth embodiment of the present invention. FIG. 35B is a sectional plan of line F—F of FIG. 35A. In the nineteenth embodiment, the center line 54 of the coolant passage 51 is inclined laterally in the direction of the upstream side of the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusion outlet 55 is inclined laterally and vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 in the lateral direction of the upstream side. A part of the cooling fluid flows from the diffusion outlet 55 to the upstream side. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is widely spread on the downstream area and the temperature is distributed uniformly on the downstream area.

[0111] FIG. 36A is a plan of an outlet of a coolant passage on the surface of the blade according to a twentieth embodiment of the present invention. FIG. 36B is a sectional plan of line G—G of FIG. 36A. In the twentieth embodiment, the center line 54 of the coolant passage 51 is inclined in the lateral direction of downstream side in relation to the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusion outlet 55 is inclined vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 to the lateral direction of the downstream side. A part of the cooling fluid flows from the diffusion outlet 55 along the gas flow. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is uniformly distributed on the downstream area.

[0112] FIG. 37A is a plan of an outlet of a coolant passage on the surface of the brade according to a twenty-first embodiment of the present invention. FIG. 37B is a sectional plan of line H—H of FIG. 37A. In the twenty-first embodiment, the center line 54 of the coolant passage 51 is inclined in the lateral direction of the downstream side of the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusion outlet 55 is inclined laterally and vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 in the lateral direction of the downstream side. A part of the cooling fluid flows from the diffusion outlet 55 in the lateral direction. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is uniformly distributed on the downstream area.

[0113] FIG. 38A is a plan of an outlet of a coolant passage on the surface of the blade according to a twenty-second embodiment of the present invention. FIG. 38B is a sectional plan of line I—I of FIG. 38A. In the twenty-second embodiment, the center line 54 of the coolant passage 51 is inclined in the lateral direction of the downstream side of the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusion outlet 55 is inclined laterally and vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 in the lateral direction of the downstream side. A part of the cooling fluid flows from the diffusion outlet 55 in the lateral direction. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is distributed uniformly over the downstream area.

[0114] FIG. 39A is a plan of an outlet of a coolant passage on the surface of the blade according to a twenty-third embodiment of the present invention. FIG. 39B is a sectional plan of line J—J of FIG. 39A. In the twenty-third embodiment, the center line 54 of the coolant passage 51 is inclined in the lateral direction of the upstream side of the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusion outlet 55 is inclined vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 in the lateral direction of the upstream side. A part of the cooling fluid flows from the diffusion outlet 55 to the upstream side. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is uniformly distributed on the downstream area.

[0115] FIG. 40A is a plan of an outlet of a coolant passage on the surface of the brade according to a twenty-fourth embodiment of the present invention. FIG. 40B is a sectional plan of line K—K of FIG. 40A. In the twenty-fourth embodiment, the center line 54 of the coolant passage 51 is inclined in the lateral direction of the upstream side of the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusion outlet 55 is inclined vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 in the lateral direction of the upstream side. A part of the cooling fluid flows from the diffusion outlet 55 in the lateral direction. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is uniformly distributed on the downstream area.

[0116] FIG. 41A is a plan of an outlet of a coolant passage on the surface of the brade according to a twenty-fifth embodiment of the present invention. FIG. 41B is a sectional plan of line L—L of FIG. 41A. In the twenty-fifth embodiment, the center line 54 of the coolant passage 51 is inclined in the lateral direction of the upstream side of the gas flow 23. The diffusion outlet 55 is partially formed on the outlet 52. The shape of the diffusing outlet 55 is inclined laterally and vertically in the direction of the gas flow 23. In this structure, the cooling fluid flows from the outlet 52 along the center line 54 in the lateral direction of the upstream side. A part of the cooling fluid flows from the diffusion outlet 55 in the lateral direction. The cooling fluid collides with the gas stream from a direction inclined to the gas flow 23. Therefore, the gas stream roll-up of the cooling fluid flowing to the downstream side is avoided. Furthermore, the cooling fluid is spread widely on the downstream area and the temperature is uniformly distributed on the downstream area.

[0117] FIG. 42 is a schematic diagram of the turbine blade including the coolant passage according to the fourteenth embodiment. In FIG. 42, the outlet 52 and the diffusion outlet 55 of FIG. 30A are applied to the leading edge 43 and the body wall 44 of the turbine brade 41.