# Patent

## Title
Film cooling for the trailing edge of a steam cooled nozzle

## Abstract

A nozzle assembly (10) for a turbine engine includes an inner band (16) and an outer band (14) spaced apart from each other. An airfoil (12) installed between the bands has a leading edge (18) and a trailing edge (20). The airfoil has cavities formed in it for fluid flow through the nozzle assembly. A plurality of film cooling holes (1A–6H) are formed in a sidewall of the airfoil on a concave side of the assembly, and a plurality of film cooling holes (1J–1R) are formed in a sidewall of the nozzle on a convex side thereof. The holes are formed on each side of the airfoil, adjacent the trailing edge of the nozzle, in a plurality of rows of holes including at least a forward row (C, J), an aft row (A, L), and an intermediate row (B, K). The spacing between the intermediate row and aft row is substantially closer than the spacing between the forward row and the intermediate row.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
This invention relates to the cooling of an airfoil comprising a portion of a stator vane or nozzle of the first stage of a gas turbine engine; and more particularly, to the hole pattern formation in the airfoil for thin film cooling of a trailing edge of the airfoil.
In the construction of gas turbine engines, an annular array of turbine segments is provided to form a turbine stage. Generally, the turbine stage is defined by outer and inner annular bands spaced apart from each other with a plurality of vanes or airfoils extending between the bands and circumferentially spaced from one other. This construction, in turn, defines a path for a working fluid flowing through the turbine. In a gas turbine engine, this is a hot gas. As will be appreciated by those skilled in the art, the most extreme adverse operating conditions are generally encountered at the first stage of the turbine. That is because this stage is immediately downstream of the engine's combustion chamber and components comprising this stage must therefore withstand high thermal loads. As is known in the art, cooling systems for this engine stage utilize thin film cooling techniques to insure so adequate cooling is provided. Thin film cooling is accomplished by discharging air through orifices formed in portions of the nozzle. The discharged air then forms a protective thin film boundary layer between the hot stream of gases flowing through the first stage of the turbine and the surface of the nozzle.
Various problems with thin film cooling systems have been encountered and solutions to these problems have been addressed in U.S. Pat. Nos. 6,583,526, 6,561,757, 6,553,665, 6,527,274, 6,517,312, 6,506,013, 6,435,814, 6,402,466, 6,398,486, and 5,591,002, all of which are assigned to the same assignee as the present application.
The present invention is directed to an advanced film-cooling configuration for cooling the trailing edge of a nozzle used in the first stage of an advanced design gas turbine engine. The nozzle is a steam cooled component which operates at firing temperatures which require cooling of the airfoil to extend the low cycle fatigue (LCF), oxidation, and creep life of the component. While steam adequately cools the majority of the nozzle, it is not feasible for use in cooling the trailing edge of the nozzle. Rather, this requires a novel and advanced thin film cooling configuration in order for the trailing edge to not rapidly deteriorate once the turbine is in service which would require costly servicing or replacement of the nozzle and unacceptable down-time when the turbine is out of service.
BRIEF SUMMARY OF THE INVENTION
Briefly stated, the present invention is directed to thin film cooling of the trailing edge of a nozzle for the first stage of a gas turbine engine. Cooling is affected by use of a plurality of rows of film cooling holes located adjacent the trailing edge of the nozzle, on both the concave side and convex side of the nozzle. In particular, three rows of film cooling holes are formed in the sidewalls of the nozzle on the respective concave and convex sides thereof. A first and forward row of holes extends generally longitudinally of the nozzle and comprises holes of varying sizes and angles formed at predetermined locations on the nozzle. Second and third rows of holes also extend generally longitudinally of the nozzle and also comprise holes of varying sizes and angles formed at predetermined locations on the nozzle. The second row of holes comprises a middle row of holes and the third row an aft row. Holes comprising the second row are spaced a substantial distance from those comprising the first row. However, the second and third row of holes are formed relatively close together with the holes comprising the second row being staggered in location with respect to those comprising the third row. By placing the middle and aft rows of holes closer together, and staggering the hole arrangement in these two rows, an effective film flow is achieved which cools the trailing edge of the nozzle thereby to minimize cooling flow, optimize performance of the turbine engine, reduce NOx produced by the engine, prolong the service life of the nozzle and reduce service and repair costs.
Two embodiments of the invention are shown with the thin film cooling arrangement of the first embodiment including substantially more holes in each row than occurs in the second embodiment.
The foregoing and other objects, features, and advantages of the invention will be in part apparent and in part pointed out hereinafter.



BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In the accompanying drawings which form part of the specification:
FIG. 1A is an orthographic view of the concave side of a first embodiment of a first stage nozzle for a gas turbine, and FIG. 1B is an orthographic view of the nozzle from the convex side;
FIG. 2 is a sectional view of an airfoil portion of the nozzle illustrating steam and air flow paths through the air foil;
FIG. 3 is a sectional view of the airfoil;
FIG. 4 is a detail view of the airfoil illustrating a film hole pattern formed in the concave side of the airfoil;
FIG. 5 is a view of the flow path side of the outer band at the trailing edge further illustrating the film hole pattern on the concave side of the airfoil;
FIGS. 6 and 7 are views similar to those of FIGS. 4 and 5, respectively, for the convex side of the airfoil;
FIGS. 8A is an orthographic view of the concave side of a second embodiment of a first stage nozzle for a gas turbine, and FIG. 8B is an orthographic view of the nozzle from the convex side;
FIG. 9 is a detail view of the airfoil illustrating a film hole pattern formed in the concave side of the airfoil;
FIG. 10 is a view of the flow path side of the outer band at the trailing edge further illustrating the film hole pattern in the concave side of the airfoil; and,
FIGS. 11 and 12 are views similar to those of FIGS. 9 and 10, respectively, for the convex side of the airfoil.



Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following detailed description illustrates the invention by way of example and not by way of limitation. The description clearly enables one skilled in the art to make and use the invention, describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
Referring to the drawings, the present invention is directed to thin film cooling for a first stage nozzle assembly, indicated generally 10 in FIGS. 1A and 1B, of a gas turbine engine. While not shown in the drawings, those skilled in the art will appreciate that nozzle assembly 10 is comprised of a plurality of circumferentially arranged vanes or airfoils indicated generally 12, the respective segments being connected to one another to form an annular array which defines a path for hot gasses passing through the first stage.
With respect to FIGS. 1A and 1B, a nozzle assembly includes an outer band 14 and an inner band 16 between which airfoil 12 is mounted. Each assembly is supported within a shell (not shown) of the turbine in which turbine components are installed. Referring to FIG. 3, airfoil 12 is shown to a have a curved airfoil shape with a rounded leading edge 18 and a trailing edge 20. A steam inlet manifold 22 and a steam outlet manifold 24 are mounted on outer band 14 to circulate steam through the airfoil. Referring to FIG. 2, airfoil 12 is constructed as is generally known in the art with a series of internal flow passages indicated generally P for steam to circulate through the airfoil from inlet manifold 22 to outlet manifold 24. These flow paths will not be described in detail. In addition to circulating steam through airfoil 12, the present invention includes an air inlet 26 in outer band 14 and a plurality of air outlet holes or slots 28 for thin film cooling of the trailing edge of the airfoil. As described hereinafter, these openings are arranged in a predetermined pattern to maximize the thin film cooling of airfoil 12. The openings are formed in the sidewalls of the airfoil on both the concave side and convex side of the airfoil. The size of each opening and its location are determined in accordance with the present invention. As shown in FIGS. 5 and 7, at the outer end of the airfoil adjacent band 14, the sidewalls of the airfoil curve or flare outwardly. In addition, the airfoil has a circumferentially extending rail 30. The holes or openings are formed in this portion of the nozzle assembly as well to provide sufficient thin film cooling at the trailing edge of the airfoil.
The hole pattern or arrangement of the present invention comprises three rows of openings which extend longitudinally of the airfoil, on both the concave and convex sides of the nozzle assembly, and spaced inwardly of the trailing edge. As particularly shown in FIG. 4, on the concave side of the airfoil are three rows indicated generally RA, RB, and RC, and on the convex side of the airfoil, as shown in FIG. 6, are three rows indicated RJ, RK, and RL. To further provide adequate thin film cooling of trailing edge 20, additional holes or slots are also formed in the curved portions of the airfoil adjacent outer band 14, and on the portion of rail 30 adjacent the trailing edge of the airfoil. On the concave side of the nozzle assembly, and as shown in FIGS. 4 and. 5, these additional openings are indicated 1D–6D, 1E, 1F–4F, 1G–5G, and 1H–6H. On the convex side of the assembly, and as shown in FIGS. 6 and 7, these additional openings are indicated 1M–6M, 1N–7N, 1P–4P, and 1R.
Referring again to FIGS. 4 and 6, the rows of holes or openings formed in the respective sidewalls of the airfoil include a forward row (the row furthest away from the trailing edge), an aft row (the row closest to the trailing edge), and an intermediate row. On the concave side of the assembly, row RC is the forward row and includes 51 openings. Row RB is the intermediate row and comprises 49 openings. The aft row is row RA which includes 43 openings. In accordance with the invention, the spacing between intermediate row RB and aft row RA is substantially closer than the spacing between forward row RC and intermediate row RB. Further, the holes comprising intermediate row RB and those comprising aft row RC are arranged in a staggered pattern as shown in FIG. 4. Similarly in accordance with the invention, on the convex side of the assembly, the spacing between intermediate row RK (which has 51 openings) and aft row RL (which has 44 openings) is substantially closer than the spacing between forward row RJ (which has 29 openings) and intermediate row RK. Again, the holes comprising intermediate row RK and those comprising aft row RL are arranged in a staggered pattern as shown in FIG. 6.
Table 1 is a listing of all the holes comprising rows RA–RC, RJ–RL, and the other holes formed in the bands 14 and 16 and rail 30. The table includes each hole designation, the angle of the opening with respect to the outer surface of airfoil 12, and the X, Y, Z coordinates determining the location of the hole. The distances are measured with respect to the reference point Q (0,0,0) shown in FIG. 1B.












TABLE 1







ANGLE TO






DIAMETER
SURFACE


HOLE #
(in.)
(°)
X (in.)
Y (in.)
Z (in.)




















 1A
0.032
30
−7.792
−2.253
.179


 2A
0.032
30
−7.777
−2.137
.223


 3A
0.032
30
−7.766
−2.021
.269


 4A
0.032
30
−7.757
−7.905
.314


 5A
0.032
30
−7.748
−1.788
.357


 6A
0.032
30
−7.741
−1.670
.398


 7A
0.032
30
−7.736
−1.559
.435


 8A
0.032
30
−7.732
−1.453
.469


 9A
0.032
30
−7.729
−1.347
.502


10A
0.032
30
−7.727
−1.241
.535


11A
0.032
30
−7.726
−1.135
.566


12A
0.032
30
−7.726
−1.028
.596


13A
0.032
30
−7.726
−.921
.625


14A
0.032
30
−7.728
−.814
.653


15A
0.032
30
−7.730
−.706
.680


16A
0.032
30
−7.732
−.598
.707


17A
0.032
30
−7.736
−.490
.732


18A
0.032
30
−7.740
−.382
.756


19A
0.032
30
−7.745
−.274
.780


20A
0.032
30
−7.750
−.165
.802


21A
0.032
30
−7.756
−.056
.822


22A
0.032
30
−7.762
.053
.840


23A
0.032
30
−7.770
.162
.860


24A
0.032
30
−7.780
.270
.882


25A
0.032
30
−7.790
.378
.906


26A
0.032
30
−7.802
.486
.929


27A
0.032
30
−7.812
.594
.950


28A
0.032
30
−7.822
.703
.968


29A
0.032
30
−7.832
.813
.983


30A
0.032
30
−7.843
.922
.997


31A
0.032
30
−7.855
1.043
1.012


32A
0.032
30
−7.870
1.174
1.028


33A
0.032
30
−7.884
1.305
1.043


34A
0.032
30
−7.898
1.437
1.057


35A
0.032
30
−7.912
1.568
1.070


36A
0.032
30
−7.931
1.744
1.085


37A
0.032
30
−7.956
1.964
1.102


38A
0.032
30
−7.980
2.164
1.114


39A
0.032
30
−8.002
2.345
1.122


40A
0.032
30
−8.031
2.553
1.130


41A
0.032
30
−8.060
2.762
1.128


42A
0.032
30
−8.091
2.969
1.136


43A
0.032
30
−8.066
3.162
1.244


 1B
0.032
37
−7.894
−3.250
.074


 2B
0.032
37
−7.906
−3.049
−.202


 3B
0.032
30
−7.845
−2.827
−.157


 4B
0.032
30
−7.790
−2.630
−.100


 5B
0.032
30
−7.779
−2.544
−.060


 6B
0.032
30
−7.744
−2.427
−.055


 7B
0.032
30
−7.730
−2.311
−.010


 8B
0.032
30
−7.715
−2.195
.033


 9B
0.032
30
−7.702
−2.079
.077


10B
0.032
30
−7.691
−1.963
.122


11B
0.032
30
−7.682
−1.846
.167


12B
0.032
30
−7.675
−1.729
.210


13B
0.032
30
−7.668
−1.611
.251


14B
0.032
30
−7.664
−1.506
.286


15B
0.032
30
−7.660
−1.400
.320


16B
0.032
30
−7.658
−1.294
.352


17B
0.032
30
−7.657
−1.188
.384


18B
0.032
30
−7.657
−1.081
.415


19B
0.032
30
−7.658
−.974
.445


20B
0.032
30
−7.659
−.867
.474


21B
0.032
30
−7.661
−.760
.502


22B
0.032
30
−7.664
−.652
.529


23B
0.032
30
−7.667
−.544
.555


24B
0.032
30
−7.671
−.436
.580


25B
0.032
30
−7.676
−.328
.604


26B
0.032
30
−7.682
−.220
.627


27B
0.032
30
−7.687
−.111
.648


28B
0.032
30
−7.694
−.002
.668


29B
0.032
30
−7.702
.107
.687


30B
0.032
30
−7.711
.216
.707


31B
0.032
30
−7.721
.324
.729


32B
0.032
30
−7.733
.432
.752


33B
0.032
30
−7.745
.540
.775


34B
0.032
30
−7.756
.649
.795


35B
0.032
30
−7.766
.755
.812


36B
0.032
30
−7.777
.868
.827


37B
0.032
30
−7.788
.977
.841


38B
0.032
30
−7.802
1.108
.858


39B
0.032
30
−7.817
1.240
.873


40B
0.032
30
−7.832
1.371
.887


41B
0.032
30
−7.848
1.502
.900


42B
0.032
30
−7.863
1.634
.912


43B
0.032
30
−7.886
1.854
.931


44B
0.032
30
−7.910
2.074
.946


45B
0.032
30
−7.931
2.255
.956


46B
0.032
30
−7.954
2.435
.963


47B
0.032
30
−7.985
2.657
.970


48B
0.032
30
−8.014
2.866
.966


49B
0.032
30
−8.042
3.072
1.028


 1C
0.032
105
−7.803
−3.190
−.429


 2C
0.032
150
−7.811
−3.013
−.421


 3C
0.032
150
−7.726
−2.763
−.348


 4C
0.032
150
−7.674
−2.550
−.304


 5C
0.032
150
−7.629
−2.335
−.267


 6C
0.032
150
−7.584
−2.121
−.230


 7C
0.032
150
−7.544
−1.908
−.190


 8C
0.032
150
−7.514
−1.692
−.146


 9C
0.032
150
−7.494
−1.476
−.098


10C
0.032
150
−7.482
−1.260
−.048


11C
0.032
150
−7.476
−1.043
−.001


12C
0.032
150
−7.470
−.824
.035


13C
0.032
150
−7.464
−.604
.062


14C
0.032
150
−7.465
−.383
.090


15C
0.032
150
−7.470
−.163
.120


16C
0.032
30
−7.481
.068
.148


17C
0.032
30
−7.494
.288
.169


18C
0.032
30
−7.508
.508
.186


19C
0.032
30
−7.523
.729
.198


20C
0.032
30
−7.539
.950
.209


21C
0.032
30
−7.558
1.170
.220


22C
0.032
30
−7.529
1.391
.230


23C
0.032
30
−7.598
1.612
.234


24C
0.032
30
−7.615
1.833
.234


25C
0.032
30
−7.632
2.054
.232


26C
0.032
30
−7.651
2.276
.228


27C
0.032
30
−7.667
2.496
.206


28C
0.032
30
−7.673
2.712
.152


29C
0.032
30
−7.678
2.919
.094


30C
0.032
30
−7.705
3.073
.102


31C
0.032
85
−7.655
3.210
.102


 1D
0.030
30
−8.537
3.433
2.152


 2D
0.030
30
−8.810
3.459
1.880


 3D
0.030
30
−7.825
3.503
1.610


 4D
0.030
30
−7.471
3.565
1.340


 5D
0.030
108
−7.017
3.668
.993


 6D
0.030
108
−6.714
3.751
.760


 1E
0.032
30
−7.980
3.215
1.252


 1F
0.032
30
−7.966
3.164
.929


 2F
0.032
30
−7.833
3.252
.954


 3F
0.032
30
−7.682
3.271
1.036


 4F
0.032
30
−7.530
3.293
1.117


 1G
0.032
30
−7.840
3.168
.558


 2G
0.032
30
−7.711
3.274
.580


 3G
0.032
30
−7.544
3.297
.664


 4G
0.032
30
−7.396
3.323
.747


 5G
0.032
30
−7.239
3.353
.830


 1H
0.032
30
−7.558
3.290
.161


 2H
0.032
30
−7.433
3.322
.247


 3H
0.032
30
−7.293
3.348
.343


 4H
0.032
30
−7.153
3.376
.439


 5H
0.032
30
−7.013
3.407
.534


 6H
0.032
30
−6.874
3.440
.630


 1J
0.032
108
−8.349
−3.250
−.676


 2J
0.032
150
−8.144
−2.937
−.568


 3J
0.032
150
−8.091
−2.727
−.519


 4J
0.032
150
−8.048
−2.515
−.480


 5J
0.032
150
−8.014
−2.298
−.450


 6J
0.032
150
−7.988
−2.080
−.424


 7J
0.032
150
−7.970
−1.861
−.397


 8J
0.032
150
−7.959
−1.643
−.365


 9J
0.032
150
−7.956
−1.425
−.322


10J
0.032
150
−7.959
−1.208
−.276


11J
0.032
150
−7.961
−.990
−.240


12J
0.032
150
−7.693
−.770
−.216


13J
0.032
150
−7.966
−.549
−.193


14J
0.032
150
−7.971
−.329
−.166


15J
0.032
150
−7.979
−.110
−.137


16J
0.032
30
−7.986
.080
−.114


17J
0.032
30
−7.996
.300
−.090


18J
0.032
30
−7.005
.521
−.070


19J
0.032
30
−8.013
.742
−.054


20J
0.032
30
−8.021
.964
−.037


21J
0.032
30
−8.031
1.185
−.018


22J
0.032
30
−8.042
1.406
−.003


23J
0.032
30
−8.052
1.627
.004


24J
0.032
30
−8.061
1.849
.008


25J
0.032
30
−8.073
2.070
.016


26J
0.032
30
−8.084
2.292
.018


27J
0.032
30
−8.091
2.512
−.008


28J
0.032
30
−8.093
2.728
−.061


29J
0.032
30
−8.093
2.939
−.123


 1K
0.032
30
−8.349
−3.250
−.676


 2K
0.032
30
−8.144
−2.937
−.568


 3K
0.032
30
−8.091
−2.727
−.519


 4K
0.032
30
−8.048
−2.515
−.480


 5K
0.032
30
−8.014
−2.298
−.450


 6K
0.032
30
−7.988
−2.080
−.424


 7K
0.032
30
−7.970
−1.861
−.397


 8K
0.032
30
−7.959
−1.643
−.365


 9K
0.032
30
−8.108
−2.206
−.088


10K
0.032
30
−8.102
−2.092
−.047


11K
0.032
30
−8.097
−1.972
−.004


12K
0.032
30
−8.093
−1.865
.038


13K
0.032
30
−8.090
−1.761
.075


14K
0.032
30
−8.089
−1.656
.111


15K
0.032
30
−8.088
−1.550
.145


16K
0.032
30
−8.088
−1.444
.179


17K
0.032
30
−8.089
−1.338
.211


18K
0.032
30
−8.091
−1.232
.243


19K
0.032
30
−8.094
−1.125
.273


20K
0.032
30
−8.096
−1.018
.303


21K
0.032
30
−8.100
−.911
.332


22K
0.032
30
−8.103
−.804
.359


23K
0.032
30
−8.106
−.696
.386


24K
0.032
30
−8.110
−.588
.412


25K
0.032
30
−8.114
−.480
.437


26K
0.032
30
−8.118
−.372
.462


27K
0.032
30
−8.123
−.264
.486


28K
0.032
30
−8.128
−.155
.508


29K
0.032
30
−8.132
−.046
.528


30K
0.032
30
−8.137
.063
.548


31K
0.032
30
−8.142
.172
.568


32K
0.032
30
−8.147
.281
.591


33K
0.032
30
−8.153
.389
.615


34K
0.032
30
−8.160
.497
.640


35K
0.032
30
−8.167
.605
.663


36K
0.032
30
−8.174
.714
.682


37K
0.032
30
−8.181
.834
.700


38K
0.032
30
−8.188
.953
.717


39K
0.032
30
−8.196
1.073
.734


40K
0.032
30
−8.203
1.192
.750


41K
0.032
30
−8.211
1.312
.764


42K
0.032
30
−8.219
1.432
.779


43K
0.032
30
−8.229
1.585
.796


44K
0.032
30
−8.239
1.738
.812


45K
0.032
30
−8.250
1.891
.826


46K
0.032
30
−8.262
2.072
.840


47K
0.032
30
−8.276
2.253
.853


48K
0.032
30
−8.294
2.474
.864


49K
0.032
30
−8.312
2.695
.872


50K
0.032
30
−8.328
2.887
.874


51K
0.032
30
−8.376
3.074
.924


 1L
0.035
30
−8.164
−2.262
.065


 2L
0.035
30
−8.156
−2.149
.107


 3L
0.035
30
−8.149
−2.035
.150


 4L
0.035
30
−8.144
−1.922
.193


 5L
0.035
30
−8.140
−1.813
.232


 6L
0.035
30
−8.137
−1.708
.268


 7L
0.035
30
−8.135
−1.603
.302


 8L
0.035
30
−8.133
−1.498
.336


 9L
0.035
30
−8.133
−1.392
.369


10L
0.035
30
−8.134
−1.285
.400


11L
0.035
30
−8.136
−1.179
.431


12L
0.035
30
−8.138
−1.072
.461


13L
0.035
30
−8.140
−.965
.490


14L
0.037
30
−8.143
−.857
.518


15L
0.037
30
−8.146
−.750
.545


16L
0.037
30
−8.149
−.642
.572


17L
0.037
30
−8.153
−.534
.597


18L
0.037
30
−8.157
−.426
.622


19L
0.037
30
−8.161
−.318
.646


20L
0.037
30
−8.165
−.209
.668


21L
0.037
30
−8.170
−.100
.689


22L
0.037
30
−8.174
.008
.709


23L
0.037
30
−8.179
.118
.729


24L
0.037
30
−8.184
.226
.751


25L
0.037
30
−8.190
.335
.776


26L
0.037
30
−8.197
.443
.801


27L
0.035
30
−8.204
.551
.824


28L
0.035
30
−8.211
.660
.844


29L
0.035
30
−8.217
.774
.862


30L
0.035
30
−8.224
.893
.879


31L
0.035
30
−8.231
1.013
.895


32L
0.035
30
−8.238
1.133
.912


33L
0.035
30
−8.246
1.252
.928


34L
0.035
30
−8.253
1.372
.942


35L
0.035
30
−8.262
1.509
.958


36L
0.035
30
−8.272
1.661
.974


37L
0.035
30
−8.283
1.814
.988


38L
0.032
30
−8.294
1.981
1.002


39L
0.032
30
−8.308
2.162
1.015


40L
0.032
30
−8.324
2.363
1.027


41L
0.032
30
−8.343
2.584
1.040


42L
0.032
30
−8.360
2.793
1.038


43L
0.032
30
−8.380
2.983
1.053


44L
0.032
30
−8.476
3.146
1.096


 1M
0.030
30
−8.964
3.524
−.771


 2M
0.030
30
−8.964
3.529
−.264


 3M
0.030
30
−8.964
3.528
.436


 4M
0.030
30
−8.964
3.520
1.003


 5M
0.030
125
−8.964
3.505
1.570


 6M
0.030
125
−8.964
3.484
2.136


 1N
0.032
30
−8.724
3.208
−.624


 2N
0.032
30
−8.625
3.208
−.558


 3N
0.032
30
−8.526
3.210
−.492


 4N
0.032
30
−8.428
3.213
−.426


 5N
0.032
30
−8.329
3.218
−.360


 6N
0.032
30
−8.246
3.210
−.304


 7N
0.032
74
−8.154
3.166
−.247


 1P
0.032
30
−8.656
3.211
.072


 2P
0.032
30
−8.572
3.211
.119


 3P
0.032
30
−8.487
3.213
.164


 4P
0.032
30
−8.402
3.215
.210


 1R
0.032
30
−8.632
3.204
.878









In FIGS. 8A–12, a second embodiment of a nozzle assembly of the present invention is indicated generally 110. This nozzle assembly includes an outer band 114 and an inner band 116 between which an airfoil 112 is mounted. Again, airfoil 112 has a curved airfoil shape with a rounded leading edge 118 and a trailing edge 120. Steam inlet manifold 122 and steam outlet manifold 124 are mounted on outer band 114 to circulate air through the airfoil, and an air inlet 126 admits air into the airfoil for discharge through holes or openings 128 for thin film cooling of the trailing edge of the airfoil. As with the previously described embodiment, the openings are formed in both the concave side and convex side of the airfoil in a predetermined pattern to maximize thin film cooling. The size of each opening and its location are again determined in accordance with the present invention. As shown in FIGS. 10 and 12, at the trailing edge of the airfoil, adjacent band 114, the sidewalls of the airfoil curve or flare outwardly to a circumferentially extending rail 130, and holes or openings are formed in this portion of the nozzle assembly.
The hole pattern for this embodiment again comprises three rows of openings which extend longitudinally of the airfoil, on both the concave and convex sides of the nozzle assembly, and spaced inwardly of the trailing edge. As particularly shown in FIG. 9, on the concave side of the airfoil are three rows indicated generally RA′, RB′, and RC′, and on the convex side of the airfoil, as shown in FIG. 11, are three rows indicated RJ′, RK′, and RL′. To further provide adequate thin film cooling, additional holes or slots are formed in the curved portions of the airfoil adjacent outer band 114, and on the portion of rail 30 adjacent the trailing edge of the airfoil. On the concave side of the nozzle assembly, and as shown in FIGS. 9 and 10, these additional openings are indicated 1D′–6D′, 1E′, 1F′–4F′, 1G′–5G′, and 1H′–6H′. On the convex side of the assembly, and as shown in FIGS. 11 and 12, these additional openings are indicated 1M′–6M′, 1N′–7N′, 1P′–4P′, and 1R′.
As shown in FIGS. 9 and 11, the rows of holes in the respective sidewalls of the airfoil include a forward row, an intermediate row, and an aft row. On the concave side of the assembly, row RC′ is the forward row and includes 31 openings. Row RB′ is the intermediate row and comprises 9 openings. The aft row is row RA′ and includes 43 openings. As previously described, the spacing between intermediate row RB′ and aft row RA′ is substantially closer than the spacing between forward row RC′ and intermediate row RB′. Further, the holes comprising intermediate row RB′ and those comprising forward row RC′ are arranged in a staggered pattern as shown in FIG. 9. On the convex side of the assembly, the spacing between intermediate row RK′ which has 10 openings, and aft row RL′ which has 44 openings, is substantially closer than the spacing between forward row RJ′ which has 29 openings, and intermediate row RK′. Again, the holes comprising intermediate row RK′ and those comprising aft row RL′ are arranged in a staggered pattern as shown in FIG. 11.
Table 2 is a listing of all the holes comprising rows RA′–RC′, RJ′–RL′, and the other holes formed in the curved outer portion of the airfoil and rai 130. The table includes each hole designation, the angle of the opening with respect to the outer surface of airfoil 112, and the X,Y,Z coordinates of the hole locations. As with FIGS. 1A and 1B, the distances are measured with respect to the reference point Q (0,0,0) shown in FIG. 8B.












TABLE 2







ANGLE







TO


HOLE #
DIAMETER
SURFACE
X (AB)
Y (AA)
Z (AC)




















 1A
.027
30
−7.792
−2.253
.179


 2A
.027
30
−7.777
−2.137
.223


 3A
.027
30
−7.766
−2.021
.269


 4A
.027
30
−7.757
−7.905
.314


 5A
.027
30
−7.748
−1.788
.357


 6A
.027
30
−7.741
−1.670
.398


 7A
.027
30
−7.736
−1.559
.435


 8A
.027
30
−7.732
−1.453
.469


 9A
.027
30
−7.729
−1.347
.502


10A
.027
30
−7.727
−1.241
.535


11A
.027
30
−7.726
−1.135
.566


12A
.027
30
−7.726
−1.028
.596


13A
.027
30
−7.726
−.921
.625


14A
.027
30
−7.728
−.814
.653


15A
.027
30
−7.730
−.706
.680


16A
.027
30
−7.732
−.598
.707


17A
.027
30
−7.736
−.490
.732


18A
.027
30
−7.740
−.382
.756


19A
.027
30
−7.745
−.274
.780


20A
.027
30
−7.750
−.165
.802


21A
.027
30
−7.756
−.056
.822


22A
.027
30
−7.762
.053
.840


23A
.027
30
−7.770
.162
.860


24A
.027
30
−7.780
.270
.882


25A
.027
30
−7.790
.378
.906


26A
.027
30
−7.802
.486
.929


27A
.027
30
−7.812
.594
.950


28A
.027
30
−7.822
.703
.968


29A
.027
30
−7.832
.813
.983


30A
.027
30
−7.843
.922
.997


31A
.027
30
−7.855
1.043
1.012


32A
.027
30
−7.870
1.174
1.028


33A
.027
30
−7.884
1.305
1.043


34A
.027
30
−7.898
1.437
1.057


35A
.027
30
−7.912
1.568
1.070


36A
.027
30
−7.931
1.744
1.085


37A
.027
30
−7.956
1.964
1.102


38A
.027
30
−7.980
2.164
1.114


39A
.027
30
−8.002
2.345
1.122


40A
.027
30
−8.031
2.553
1.130


41A
.027
30
−8.060
2.762
1.128


42A
.027
30
−8.091
2.969
1.136


43A
.027
30
−8.066
3.162
1.244


 1B
.027
37
−7.894
−3.250
.074


 2B
.027
37
−7.906
−3.049
−.202


 3B
.027
30
−7.845
−2.827
−.157


 4B
.027
30
−7.790
−2.630
−.100


 5B
.027
30
−7.779
−2.544
−.060


 6B
.027
30
−7.744
−2.427
−.055


 7B
.027
30
−7.730
−2.311
−.010


48B
.027
30
−8.014
2.866
.966


49B
.027
30
−8.042
3.072
1.028


 1C
.029
105
−7.803
−3.190
−.429


 2C
.029
150
−7.811
−3.013
−.421


 3C
.029
150
−7.726
−2.763
−.348


 4C
.029
150
−7.674
−2.550
−.304


 5C
.029
150
−7.629
−2.335
−.267


 6C
.029
150
−7.584
−2.121
−.230


 7C
.029
150
−7.544
−1.908
−.190


 8C
.029
150
−7.514
−1.692
−.146


 9C
.029
150
−7.494
−1.476
−.098


10C
.029
150
−7.482
−1.260
−.048


11C
.029
150
−7.476
−1.043
−.001


12C
.029
150
−7.470
−.824
.035


13C
.029
150
−7.464
−.604
.062


14C
.029
150
−7.465
−.383
.090


15C
.029
150
−7.470
−.163
.120


16C
.029
30
−7.481
.068
.148


17C
.029
30
−7.494
.288
.169


18C
.029
30
−7.508
.508
.186


19C
.029
30
−7.523
.729
.198


20C
.029
30
−7.539
.950
.209


21C
.029
30
−7.558
1.170
.220


22C
.029
30
−7.529
1.391
.230


23C
.029
30
−7.598
1.612
.234


24C
.029
30
−7.615
1.833
.234


25C
.029
30
−7.632
2.054
.232


26C
.029
30
−7.651
2.276
.228


27C
.029
30
−7.667
2.496
.206


28C
.029
30
−7.673
2.712
.152


29C
.029
30
−7.678
2.919
.094


30C
.029
30
−7.705
3.073
.102


31C
.029
85
−7.655
3.210
.102


 1D
.030
30
−8.537
3.433
2.152


 2D
.030
30
−8.810
3.459
1.880


 3D
.030
30
−7.825
3.503
1.610


 4D
.030
30
−7.471
3.565
1.340


 5D
.030
108
−7.017
3.668
.993


 6D
.030
108
−6.714
3.751
.760


 1E
.032
30
−7.966
3.215
1.252


 1F
.032
30
−7.966
3.164
.929


 2F
.032
30
−7.833
3.252
.954


 3F
.032
30
−7.682
3.271
1.036


 4F
.032
30
−7.530
3.293
1.117


 1G
.032
30
−7.840
3.168
.558


 2G
.032
30
−7.711
3.274
.580


 3G
.032
30
−7.544
3.297
.664


 4G
.032
30
−7.396
3.323
.747


 5G
.032
30
−7.239
3.353
.830


 1H
.032
30
−7.558
3.290
.161


 2H
.032
30
−7.433
3.322
.247


 3H
.032
30
−7.293
3.348
.343


 4H
.032
30
−7.153
3.376
.439


 5H
.032
30
−7.013
3.407
.534


 6H
.032
30
−6.874
3.440
.630


 1J
.028
108
−8.349
−3.250
−.676


 2J
.028
150
−8.144
−2.937
−.568


 3J
.028
150
−8.091
−2.727
−.519


 4J
.028
150
−8.048
−2.515
−.480


 5J
.028
150
−8.014
−2.298
−.450


 6J
.028
150
−7.988
−2.080
−.424


 7J
.028
150
−7.970
−1.861
−.397


 8J
.028
150
−7.959
−1.643
−.365


 9J
.028
150
−7.956
−1.425
−.322


10J
.028
150
−7.959
−1.208
−.276


11J
.028
150
−7.961
−.990
−.240


12J
.028
150
−7.693
−.770
−.216


13J
.028
150
−7.966
−.549
−.193


14J
.028
150
−7.971
−.329
−.166


15J
.028
150
−7.979
−.110
−.137


16J
.028
30
−7.986
.080
−.114


17J
.028
30
−7.996
.300
−.090


18J
.028
30
−7.005
.521
−.070


19J
.028
30
−8.013
.742
−.054


20J
.028
30
−8.021
.964
−.037


21J
.028
30
−8.031
1.185
−.018


22J
.028
30
−8.042
1.406
−.003


23J
.028
30
−8.052
1.627
.004


24J
.028
30
−8.061
1.849
.008


25J
.028
30
−8.073
2.070
.016


26J
.028
30
−8.084
2.292
.018


27J
.028
30
−8.091
2.512
−.008


28J
.028
30
−8.093
2.728
−.061


29J
.028
30
−8.093
2.939
−.123


 1K
.028
30
−8.349
−3.250
−.676


 2K
.028
30
−8.144
−2.937
−.568


 3K
.028
30
−8.091
−2.727
−.519


 4K
.028
30
−8.048
−2.515
−.480


 5K
.028
30
−8.014
−2.298
−.450


 6K
.028
30
−7.988
−2.080
−.424


 7K
.028
30
−7.970
−1.861
−.397


 8K
.028
30
−7.959
−1.643
−.365


50K
.027
30
−8.328
2.887
.874


51K
.027
30
−8.376
3.074
.924


 1L
.029
30
−8.164
−2.262
.065


 2L
.029
30
−8.156
−2.149
.107


 3L
.029
30
−8.149
−2.035
.150


 4L
.029
30
−8.144
−1.922
.193


 5L
.029
30
−8.140
−1.813
.232


 6L
.029
30
−8.137
−1.708
.268


 7L
.029
30
−8.135
−1.603
.302


 8L
.029
30
−8.133
−1.498
.336


 9L
.029
30
−8.133
−1.392
.369


10L
.029
30
−8.134
−1.285
.400


11L
.029
30
−8.136
−1.179
.431


12L
.029
30
−8.138
−1.072
.461


13L
.029
30
−8.140
−.965
.490


14L
.030
30
−8.143
−.857
.518


15L
.030
30
−8.146
−.750
.545


16L
.030
30
−8.149
−.642
.572


17L
.030
30
−8.153
−.534
.597


18L
.030
30
−8.157
−.426
.622


19L
.030
30
−8.161
−.318
.646


20L
.030
30
−8.165
−.209
.668


21L
.030
30
−8.170
−.100
.689


22L
.030
30
−8.174
.008
.709


23L
.030
30
−8.179
.118
.729


24L
.030
30
−8.184
.226
.751


25L
.030
30
−8.190
.335
.776


26L
.030
30
−8.197
.443
.801


27L
.029
30
−8.204
.551
.824


28L
.029
30
−8.211
.660
.844


29L
.029
30
−8.217
.774
.862


30L
.029
30
−8.224
.893
.879


31L
.029
30
−8.231
1.013
.895


32L
.029
30
−8.238
1.133
.912


33L
.029
30
−8.246
1.252
.928


34L
.029
30
−8.253
1.372
.942


35L
.029
30
−8.262
1.509
.958


36L
.029
30
−8.272
1.661
.974


37L
.029
30
−8.283
1.814
.988


38L
.028
30
−8.294
1.981
1.002


39L
.028
30
−8.308
2.162
1.015


40L
.028
30
−8.324
2.363
1.027


41L
.028
30
−8.343
2.584
1.040


42L
.028
30
−8.360
2.793
1.038


43L
.028
30
−8.380
2.983
1.053


44L
.028
30
−8.476
3.146
1.096


 1M
.030
30
−8.964
3.524
−.771


 2M
.030
30
−8.964
3.529
−.264


 3M
.030
30
−8.964
3.528
.436


 4M
.030
30
−8.964
3.520
1.003


 5M
.030
125
−8.964
3.505
1.570


 6M
.030
125
−8.964
3.484
2.136


 1N
.032
30
−8.724
3.208
−.624


 2N
.032
30
−8.625
3.208
−.558


 3N
.032
30
−8.526
3.210
−.492


 4N
.032
30
−8.428
3.213
−.426


 5N
.032
30
−8.329
3.218
−.360


 6N
.032
30
−8.246
3.210
−.304


 7N
.032
74
−8.154
3.166
−.247


 1P
.032
30
−8.656
3.211
.072


 2P
.032
30
−8.572
3.211
.119


 3P
.032
30
−8.487
3.213
.164


 4P
.032
30
−8.402
3.215
.210


 1R
.032
30
−8.632
3.204
.878









In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results are obtained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

## Claims

1. A nozzle assembly for a turbine engine comprising:
an inner band and an outer band spaced apart from each other; a nozzle installed between the bands and having an inner segment and a trailing edge, the nozzle having cavities formed therein for fluid flow through the nozzle assembly;
a plurality of film cooling holes formed in a sidewall of the nozzle on a concave side thereof and a plurality of film cooling holes formed in a sidewall of the nozzle on a convex side thereof, the film cooling holes being formed on each side of the nozzle in a plurality of rows of holes including at least a forward row, an aft row, and a row intermediate the forward and aft rows, the spacing between the intermediate row and aft row being substantially closer together than the spacing between the forward row and the intermediate row; and
wherein the size and location of each hole are set forth in Table 1.

2. A nozzle assembly for a turbine engine comprising:
an inner band and an outer band spaced apart from each other; a nozzle installed between the bands and having an inner segment and a trailing edge, the nozzle having cavities formed therein for fluid flow through the nozzle assembly;
a plurality of film cooling holes formed in a sidewall of the nozzle on a concave side thereof and a plurality of film cooling holes formed in a sidewall of the nozzle on a convex side thereof, the film cooling holes being formed on each side of the nozzle in a plurality of rows of holes including at least a forward row, an aft row, and a row intermediate the forward and aft rows, the spacing between the intermediate row and aft row being substantially closer together than the spacing between the forward row and the intermediate row; and
wherein the size and location of each hole are set forth in Table 2.

3. In a gas turbine engine, a first stage nozzle assembly comprising:
a plurality of circumferentially arranged nozzle segments with the respective segments being connected to one another to form an annular array defining a path for hot gasses passing through the first stage;
each segment including an inner band and an outer band spaced apart from each other with an airfoil installed between the bands, the airfoil having an inner segment and a trailing edge, and cavities formed therein for fluid flow through the airfoil;
a plurality of film cooling holes formed in respective sidewalls of the airfoil on a concave side and a convex side of the airfoil, the film cooling holes being formed on each side of the airfoil, in a plurality of rows of holes including a forward row, an intermediate row, and an aft row, with the spacing between the intermediate row and the aft row being substantially closer together than the spacing between the forward row and the intermediate row; and
wherein the size and location of each hole are set forth in Table 1.

4. In a gas turbine engine, a first stage nozzle assembly comprising:
a plurality of circumferentially arranged nozzle segments with the respective segments being connected to one another to form an annular array defining a path for hot gasses passing through the first stage;
each segment including an inner band and an outer band spaced apart from each other with an airfoil installed between the bands, the airfoil having an inner segment and a trailing edge, and cavities formed therein for fluid flow through the airfoil;
a plurality of film cooling holes formed in respective sidewalls of the airfoil on a concave side and a convex side of the airfoil, the film cooling holes being formed on each side of the airfoil, in a plurality of rows of holes including a forward row, an intermediate row, and an aft row, with the spacing between the intermediate row and the aft row being substantially closer together than the spacing between the forward row and the intermediate row; and
wherein the size and location of each hole are set forth in Table 2.