Turbomachine and turbine guide vanes for it

Abstract

Turbomachine (10) comprising multiple guide vanes (36), each guide vane (36) comprising a blade (37), wherein the turbomachine (10) comprises: opposing walls (40, 42) defining a passage (38) in which a fluid flow is received to flow through the passage (38), wherein a constriction distribution (Do) is measured in a narrowest region in the passage (38) between adjacent guide vanes (36), in which adjacent guide vanes (36) extend transversely across the passage between the opposing walls (40, 42) to interact aerodynamically with the fluid flow; and wherein the blade (37) defines the constriction distribution (Do), wherein the constriction distribution (Do) reduces aerodynamic losses and improves aerodynamic loads on the blade (37);characterized in that the bottleneck distribution (Do) is defined by values ​​specified in Table 1 and wherein the values ​​of the bottleneck distribution (Do) lie within a tolerance of + / -10% of the values ​​specified in Table 1.

Description

BACKGROUND TO THE INVENTION The subject matter disclosed herein relates to turbomachinery and in particular to a guide vane in a turbomachine. A turbomachine, such as a gas turbine, can contain a compressor, a combustion chamber, and a turbine. In the compressor, air is compressed. The compressed air is fed into the combustion chamber. The combustion chamber combines a fuel with the compressed air and then ignites the gas / fuel mixture. The exhaust gases, which have a high temperature and high energy, are then fed to the turbine, where the energy of the fluids is converted into mechanical energy. The turbine contains several stages of guide vanes and stages of rotor blades. The guide vanes are stationary components, and the rotor blades rotate on a rotor. US 2013 / 0104566A1 discloses a turbomachine with the features of the preamble of claim 1 and a guide vane with the features of the preamble of claim 4. Based on this, it is an object of the invention to further develop a turbomachine and a guide vane for use in a turbomachine in such a way that aerodynamic losses can be reduced and aerodynamic loads on the blade of the guide vane can be improved. This problem is solved by a turbomachine with the features of independent claim 1 and a guide vane with the features of dependent claims 4 and 5. Particularly preferred embodiments of the invention are the subject of the dependent claims. BRIEF DESCRIPTION OF THE INVENTION Certain embodiments that correspond to the scope of the originally claimed subject matter are briefly summarized below. These embodiments are not intended to limit the scope of protection of the claimed subject matter, but rather to provide a brief description of possible forms of the claimed subject matter. In fact, the claimed subject matter can take many forms that may be similar to or differ from the aspects / embodiments described below. In one aspect, a turbomachine contains multiple guide vanes, and each guide vane has a blade. The turbomachine has opposing walls that define a passage through which a fluid flow can be accommodated. A constriction distribution is measured in a narrowest region in the passage between adjacent guide vanes, where adjacent guide vanes extend transversely across the passage between the opposing walls to interact aerodynamically with the fluid flow. The blade defines the constriction distribution, and the constriction distribution reduces aerodynamic losses and improves aerodynamic loads on each blade. The constriction distribution is defined by values ​​given in Table 1, with the constriction distribution values ​​falling within a tolerance of ±10% of the values ​​given in Table 1. In the embodiment of the turbomachine, it may be advantageous for a trailing edge of the blade to have a projection at a span of approximately 50% and for the trailing edge of the blade to have an offset as defined by the values ​​given in Table 2. In each embodiment of the turbomachine, it can be advantageous for the blade to have a thickness distribution (Tmax / Tmax_midspan) as defined by the values ​​given in Table 3. In every embodiment of the turbomachine, it can be advantageous for the blade to have a dimensionless thickness distribution according to the values ​​given in Table 4. In every embodiment of the turbomachine, it can be advantageous for the blade to have a dimensionless axial chord distribution according to the values ​​given in Table 5. In another aspect, a guide vane has a blade, and the guide vane is designed for use with a turbomachine. The blade has a constriction distribution, measured in the narrowest area in a passage between adjacent guide vanes, where adjacent guide vanes extend across the passage between opposing walls to interact aerodynamically with a fluid flow. The blade defines the constriction distribution, and this distribution reduces aerodynamic losses and improves aerodynamic loads on the blade.The constriction distribution, as defined by a trailing edge of the guide vane, extends curvilinearly from a constriction / constriction mid-span value of approximately 111% at approximately 0% span to a constriction / constriction mid-span value of approximately 100% at approximately 51% span, to a constriction / constriction mid-span value of approximately 123% at approximately 100% span, where the span at 0% is located on a radially inner section of the airfoil, while a span at 100% is located on a radially outer section of the airfoil. In each embodiment of the guide vane, the constriction distribution can be defined by values ​​specified in Table 1, wherein the constriction distribution values ​​are preferably within a tolerance of + / -10% of the values ​​specified in Table 1. In every embodiment of the guide vane, it can be advantageous for a trailing edge of the blade to have a projection at approximately 50% of its span. In each embodiment of the guide vane, a trailing edge of the blade can have an offset of approximately 0 at approximately 0% span, approximately 100% at approximately 50% span, and approximately 0 at approximately 100% span. In each embodiment of the guide vane, a trailing edge of the blade can have an offset as defined by the values ​​given in Table 2. In each embodiment of the guide vane, the blade can have a thickness distribution (Tmax / Tmax_midspan) as defined by the values ​​given in Table 3. In each embodiment of the guide vane, the blade can have a dimensionless thickness distribution according to the values ​​given in Table 4. In each embodiment of the guide vane, the blade can have a dimensionless axial chord distribution according to the values ​​given in Table 5. In a further aspect, a guide vane comprises a blade, and the guide vane is designed for use with a turbomachine. The blade has a constriction distribution, measured in the narrowest region of a passage between adjacent guide vanes, where adjacent guide vanes extend across the passage between opposing walls to interact aerodynamically with a fluid flow. The blade defines the constriction distribution, and the constriction distribution is defined by values ​​given in Table 1, the constriction distribution values ​​preferably being within a tolerance of ±10% of the values ​​given in Table 1. The constriction distribution reduces aerodynamic losses and improves aerodynamic loads on the blade. In each embodiment of the guide vane, a trailing edge of the blade may have a projection at approximately 50% of the span, and the trailing edge of the blade may have an offset as defined by the values ​​given in Table 2. In each embodiment of the guide vane, the blade can have a thickness distribution (Tmax / Tmax_midspan) as defined by the values ​​given in Table 3. In each embodiment of the guide vane, the blade can have a dimensionless thickness distribution according to the values ​​given in Table 4. In each embodiment of the guide vane, the blade can have a dimensionless axial chord distribution according to the values ​​given in Table 5. BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of the present disclosure will be better understood if the following detailed description is read with reference to the accompanying drawings, in which the same reference numerals denote the same parts throughout the drawings, wherein: Fig. 1 shows a schematic representation of a turbomachine according to aspects of the present disclosure; Fig. 2 shows a perspective view of a guide vane according to aspects of the present disclosure; Fig. 3 shows a top view of two adjacent guide vanes according to aspects of the present disclosure; Fig. 4 shows a graphical representation of the constriction distribution according to aspects of the present disclosure; Fig. 5 shows a graphical representation of a trailing edge offset according to aspects of the present disclosure; Fig. 6 shows a graphical representation of a maximum thickness distribution according to aspects of the present disclosure; Fig.7 a graphical representation of the maximum thickness, divided by the axial chord distribution, according to aspects of the present disclosure; and Fig. 8 a graphical representation of the axial chord, divided by the axial chord at the midspan, according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION One or more specific embodiments of the present disclosure are described below. In an effort to provide a concise description of these embodiments, the description may not include all features of an actual implementation. It should be recognized that, as in any engineering or design project, the development of any such actual implementation requires numerous implementation-specific decisions to be made in order to achieve the specific goals of the developers, such as compliance with system-related and company-related constraints, which may vary from one implementation to another.Furthermore, it should be recognized that while such a development effort may be complex and time-consuming, for experts in the field who benefit from this disclosure it would nevertheless represent a routine undertaking for design, manufacture and production. When elements of different embodiments of the present object are introduced, the articles "a", "an", and "the" or "a" shall mean that one or more of the elements may be present. The expressions "have", "contain", and "have" shall be meant inclusively and mean that, in addition to the elements listed, further elements may be present. Fig. 1 shows a diagram of an embodiment of a turbomachine 10 (e.g., a gas turbine and / or a compressor). The turbomachine 10, as illustrated in Fig. 1, comprises a compressor 12, a combustion chamber 14, a turbine 16, and a diffuser 17. Air, or any other gas, is compressed in the compressor 12, fed into the combustion chamber 14, mixed with a fuel, and subsequently combusted. The exhaust fluids are fed to the turbine 16, where energy from the exhaust fluids is converted into mechanical energy. The turbine 16 comprises several stages 18, including a single stage 20. Each stage 18 comprises a rotor (i.e., a rotating shaft) with an annular arrangement of axially aligned rotor blades rotating about an axis of rotation 26, and a stator with an annular arrangement of guide vanes. Accordingly, the stage 20 may comprise a guide vane stage 22 and a rotor blade stage 24.For clarity, Fig. 1 includes a coordinate system comprising an axial direction 28, a radial direction 32, and a circumferential direction 34. A radial plane 30 is also illustrated. The radial plane 30 extends in the axial direction 28 (along the axis of rotation 26) in one direction and then extends outwards in the radial direction 32. Fig. 2 shows a perspective view of two guide vanes 36. The guide vanes 36 in stage 20 extend in a radial direction 32 between a first wall (or platform) 40 and a second wall 42. The first wall 40 faces the second wall 42, and both walls define a path or passage in which a fluid flow can be received. The guide vanes 36 are arranged circumferentially 34 around a hub. Each guide vane 36 has a blade 37, and the blade 37 is configured to interact aerodynamically with the exhaust fluids from the combustion chamber 14, while the exhaust fluids flow substantially downstream through the turbine 16 in the axial direction 28. Each guide vane 36 has a leading edge 44, a trailing edge 46 which is arranged downstream of the leading edge 44 in the axial direction 28, a pressure side 48 and a suction side 50.The pressure side 48 extends in the axial direction 28 between the leading edge 44 and the trailing edge 46, and in the radial direction 42 between the first wall 40 and the second wall 42. The suction side 50 extends in the axial direction 28 between the leading edge 44 and the trailing edge 46, and in the radial direction 32 between the first wall 40 and the second wall 42, opposite the pressure side 48. The guide vanes 36 in stage 20 are arranged such that the pressure side 48 of one guide vane 36 faces the suction side 50 of an adjacent guide vane 36. As the exhaust fluids flow to and through the passage between the guide vanes 36, they interact aerodynamically with the guide vanes 36 such that they flow with an angular momentum or velocity relative to the axial direction 28.A guide vane stage 22, equipped with guide vanes 36 having a special constriction distribution designed to show reduced aerodynamic losses and improved aerodynamic loads, can result in improved machine efficiency and improved part durability. Fig. 3 shows a top view of two adjacent guide vanes 36. Note that the suction side 50 of the lower guide vane 36 faces the pressure side 48 of the upper guide vane 36. The axial chord 56 is the dimension of the guide vane 36 in the axial direction 28. The chord 57 is the distance between the leading and trailing edges of the blade. The passage 38 between two adjacent guide vanes 36 of a stage 18 defines a constriction distribution Do, which is measured in the narrowest part of the passage 38 between adjacent guide vanes 36. A fluid flows through the passage 38 in the axial direction 28. This constriction distribution Do over the span from the first wall 40 to the second wall 42 is explained in greater detail below with reference to Fig. 4. The maximum thickness of each guide vane 36 at a given percentage span is illustrated as Tmax.The Tmax distribution over the height of the guide vane 36 is explained in greater detail below with reference to Fig. 4. Fig. 4 shows a graphical representation of the constriction distribution Do, defined by adjacent guide vanes 36 and depicted as a curve 60. The vertical axis represents the percentage span between the first annular wall 40 and the second annular wall 42, or the opposite end of the airfoil 37, in the radial direction 32. That is, 0% span essentially denotes the first annular wall 40, and 100% span denotes the opposite end of the airfoil 37, and any point between 0% and 100% corresponds to a percentage of the distance between the radially inner and radially outer parts of the airfoil 37 in the radial direction 32 along the height of the airfoil.The horizontal axis represents Do(narrowness), the shortest distance between two adjacent guide vanes 36 at a given percentage span, divided by Do_midspan(narrowness_midspan), which is Do at approximately 50% to approximately 55% of the span. Dividing Do by Do_midspan makes the graphical representation 58 dimensionless, so that the curve 60 remains the same when the guide vane stage 22 is scaled up or down for different applications. A similar graphical representation could be created for a single turbine size, in which the horizontal axis is Do. As can be seen in Fig. 4, the constriction distribution, as defined by the trailing edge of the guide vane, follows a curve from a constriction / constriction_center-span value of approximately 111% at approximately 0% span (point 66) to a constriction / constriction_center-span value of approximately 100% at approximately 51% span (point 68) and to a constriction / constriction_center-span value of approximately 122% at approximately 100% span (point 70). The span at 0% is located on a radially inner part of the blade, and the span at 100% is located on a radially outer part of the blade. The constriction / constriction_center-span value is 115% at approximately 51% span (point 68). The constriction distribution illustrated in Fig. 4 can help improve performance in two ways. First, the constriction distribution helps to generate desired outlet flow profiles. Second, the constriction distribution illustrated in Fig. 4 can help to control secondary flows (e.g.,to manipulate flows perpendicular to the main flow direction) and / or flushing flows near the first annular wall 40 (e.g., the hub). Table 1 lists the constriction distribution and various values ​​for the trailing edge shape of the blade 37 at several points along the span. Fig. 4 shows a graphical representation of the constriction distribution. It should be understood that the constriction distribution values ​​can vary by approximately + / -10%. Table 1 1001,2228 95,451,1872 90,781,1538 81,181,0945 71,321,0494 61,251,0179 50,991 40,610,9958 30,261,0048 19,991,0263 9,861,0605 4,881,0822 01,1065 Fig. 5 shows a graphical representation of the trailing edge offset of the blade 37 of the guide vane 36. The trailing edge 46 has a projection 500 at a span of approximately 50%. The vertical axis represents the percentage span between the first annular wall 40 and the opposite end of the blade 37 in the radial direction 32. The horizontal axis represents the trailing edge offset to a straight line extending from a line 510 (see Fig. 2) running from a radially inner section of the trailing edge to a radially outer section of the trailing edge. The projection 500 is greatest at approximately 50% of the span (i.e., 1 or 100%) and then gradually decreases to an offset value of 0 at approximately 0% of the span and approximately 100% of the span. The maximum trailing edge offset (i.e.,The trailing edge offset (at approximately 50% of the span) is approximately 0.635 cm (0.25 in), although this will change if the guide vane is scaled up or down. Furthermore, a guide vane 36 with a trailing edge offset increased around 50% of the span can help tune the guide vane's resonant frequency to avoid interference with drive components. If the guide vane's resonant frequency is not carefully tuned to avoid interference with drive components, operation may result in impermissible loading on the guide vane 36 and potential structural failure. Accordingly, a guide vane 36 design with the projection 500 or the increased trailing edge offset, as illustrated in Fig. 5, can extend the guide vane 36's service life. Table 2 lists the trailing edge offset and projection shape for various values ​​of the blade 37's trailing edge at several points along the span.Table 2 Table 2. 1000 900,359 750,749 501 250,749 100,363 00 Fig. 6 shows a graphical representation of the thickness distribution Tmax / Tmax_midspan as defined by the thickness of the guide vane blade 37. The vertical axis represents the percentage span between the first annular wall 40 and the opposite end of the guide vane blade 37 in the radial direction 32. The horizontal axis represents Tmax divided by the Tmax_midspan value. Tmax is the maximum thickness of the guide vane blade at a given span, and Tmax_midspan is the maximum thickness of the guide vane blade at the midspan (e.g., at approximately 50% to 55% of the span). Dividing Tmax by Tmax_midspan makes the graphical representation dimensionless, so the curve remains the same when the guide vane stage 22 is scaled up or down for different applications.Referring to Table 3, a mid-span value of approximately 50% has a Tmax / Tmax_mid-span value of 1, because at this span Tmax equals Tmax_mid-span. Table 3 1000,985 94,810,988 89,660,988 79,490,992 69,480,994 59,630,998 49,791,000 39,951,000 30,101,001 20,161,002 10,131,001 5,081,000 00.999 Fig. 7 shows a graphical representation of the blade thickness (Tmax) divided by the axial chord of the blade at various span values. The vertical axis represents the percentage span between the first annular wall 40 and the opposite end of the blade 37 in the radial direction 32. The horizontal axis represents Tmax divided by the axial chord value. Dividing the blade thickness by the axial chord makes the graphical representation dimensionless, so the curve remains the same when the guide vane stage 22 is scaled up or down for different applications. A guide vane design with the Tmax distribution illustrated in Figs. 6 and 7 can help to tune the guide vane's resonant frequency to avoid interference with drive systems. Accordingly, a guide vane design 36 with the distribution shown in Figs. 6 and 7 can be used to achieve the same resonant frequency as shown in Figs. 6 and 7.Figure 7 illustrates how the Tmax distribution increases the service life of the guide vane 36. Table 4 lists the Tmax / axial chord value for various span values, where the dimensionless thickness is defined as the ratio of Tmax to the axial chord at a given span. 1000,498 94,810,499 89,660,499 79,490,501 69,480,503 59,630,504 49,790,506 39,950,506 30,100,506 20,160,506 10,130,506 5,080,505 00.505 Fig. 8 shows a graphical representation of the axial chord of the airfoil, divided by the axial chord value at the mid-span at various span values. The vertical axis represents the percentage span between the first annular wall 40 and the opposite end of the airfoil 37 in the radial direction 32. The horizontal axis represents the axial chord divided by the axial chord at the mid-span value. Referring to Table 5, a mid-span value of approximately 50% has an axial-chord / axial-chord_mid-span value of 1, because at this span the axial chord is equal to the axial chord at the mid-span. Dividing the axial chord by the axial chord at the mid-span makes the graphical representation dimensionless, so the curve remains the same when the guide vane stage 22 is scaled up or down for different applications.Table 5 lists the values ​​for the axial chord of the blade, divided by the axial chord value at the mid-span, along various span values, where the dimensionless axial chord is defined as a ratio of the axial chord at a given span to the axial chord at the mid-span. 1000.99995 94,810,99995 89,660,99995 79,490,99993 69,480,99997 59,631,00000 49,791,00000 39,950,99999 30,100,99996 20,161,00085 10,131,00094 5,081,00108 01,00118 A guide vane design with the axial chord distribution illustrated in Fig. 8 can help to tune the guide vane's resonant frequency to avoid interference with drive components. For example, a guide vane with a linear shape may have a resonant frequency of 400 Hz, while a guide vane 36 with increased thickness at some spans may have a resonant frequency of 450 Hz. If the guide vane's resonant frequency is not carefully adjusted to avoid interference with the drive components, operation may result in impermissible stress on the guide vane 36 and potential structural failure. Accordingly, a guide vane 36 design with the axial chord distribution illustrated in Fig. 8 can extend the guide vane's service life. The technical effects of the disclosed embodiments include an improvement in the turbine's performance in several different ways. First, the design of the guide vanes 36 and the constriction distribution, as illustrated in Fig. 4, can help to manipulate secondary flows (i.e., flows perpendicular to the main flow direction) and / or scavenging flows near the hub (e.g., the first annular wall 40). Second, a guide vane 36 with a projection 500 around the 50% span can help to tune the guide vane's resonant frequency to avoid interference with drive components. If the guide vane's resonant frequency is not carefully tuned to avoid interference with drive components, operation can result in overloading of the guide vane 36 and potential structural failure.Accordingly, a design of the guide vane 36 with increased thickness at special clamping points can extend the service life of the guide vane 36. This written description uses examples to disclose the subject matter of the invention, including the best embodiment, and also to enable any person skilled in the art to carry out the subject matter of the invention, including the creation and use of any devices or systems and the performance of any methods contained therein. The patentable scope of the invention is defined by the claims. A turbomachine contains multiple guide vanes, and each guide vane has a blade. The turbomachine has opposing walls that define a passage through which a fluid flow can be accommodated. A constriction distribution is measured at the narrowest point in the passage between adjacent guide vanes, where adjacent guide vanes extend across the passage between the opposing walls to interact aerodynamically with the fluid flow. The blade defines the constriction distribution, and this distribution reduces aerodynamic losses and improves aerodynamic loads on each blade. Parts list: 10 Turbomachine 12 Compressor 14 Combustion chamber 16 Turbine 17 Diffuser 18 Stages 20 Stage 22 Guide vane stage 24 Rotor blade stage 26 Axis of rotation 28 Axial direction, X-axis 30 Radial plane 32 Y-axis 34 Circumferential direction 36 Guide vane 37 Blade 38 Passage 39 Mounting section 40 First wall or platform 42 Second wall 44 Leading edge 46 Trailing edge 48 Pressure side 50 Suction side 56 Axial chord 57 Chord 58 Graphical representation 60 Curve 66 Point 68 Point 70 Point 500 Projection 510 Line

Claims

Turbomachine (10) comprising multiple guide vanes (36), each guide vane (36) comprising a blade (37), wherein the turbomachine (10) comprises: opposing walls (40, 42) defining a passage (38) in which a fluid flow is received to flow through the passage (38), wherein a constriction distribution (Do) is measured in a narrowest region in the passage (38) between adjacent guide vanes (36), in which adjacent guide vanes (36) extend transversely across the passage between the opposing walls (40, 42) to interact aerodynamically with the fluid flow; and wherein the blade (37) defines the constriction distribution (Do), wherein the constriction distribution (Do) reduces aerodynamic losses and improves aerodynamic loads on the blade (37);characterized in that the bottleneck distribution (Do) is defined by values ​​specified in Table 1 and wherein the values ​​of the bottleneck distribution (Do) lie within a tolerance of + / -10% of the values ​​specified in Table 1. Turbomachine (10) according to claim 1, wherein a trailing edge (46) of the blade (37) has a projection (500) at about 50% of the span and the trailing edge (46) of the blade (37) has an offset as defined by values ​​given in Table 2. Turbomachine (10) according to any one of the preceding claims, wherein the blade (37) has a thickness distribution (Tmax / Tmax_midspan) as defined by values ​​specified in Table 3 and / or wherein the blade (37) has a dimensionless thickness distribution according to values ​​specified in Table 4 and / or wherein the blade (37) has a dimensionless axial chord distribution according to values ​​specified in Table 5. Guide vane (36) comprising a blade (37), wherein the guide vane (36) is configured for use with a turbomachine (10), the blade (37) comprising: a constriction distribution (Do) measured in a narrowest region in a passage (38) between adjacent guide vanes (36), in which adjacent guide vanes (36) extend transversely across the passage (38) between opposing walls (40, 42) to interact aerodynamically with a fluid flow; and wherein the blade (37) defines the constriction distribution (Do), the constriction distribution (Do) reducing aerodynamic losses and improving aerodynamic loads on the blade (37);characterized in that the constriction distribution (Do), as defined by a trailing edge (46) of the guide vane (36), extends curvilinearly from a constriction / constriction mid-span value of approximately 111% at approximately 0% span to a constriction / constriction mid-span value of approximately 100% at approximately 51% span, to a constriction / constriction mid-span value of approximately 123% at approximately 100% span; and wherein the span at 0% is located at a radially inner section of the airfoil (37), while a span at 100% is located at a radially outer section of the airfoil (37). Guide vane (36) comprising a blade (37), wherein the guide vane (36) is configured for use with a turbomachine (10), wherein the blade (37) comprises: a constriction distribution (Do) measured in a narrowest region in a passage (38) between adjacent guide vanes (36), in which adjacent guide vanes (36) extend transversely across the passage (38) between opposing walls (40, 42) to interact aerodynamically with a fluid flow; and wherein the blade (37) defines the constriction distribution (Do), characterized in that the constriction distribution (Do) is defined by values ​​specified in Table 1, and wherein the values ​​of the constriction distribution (Do) are within a tolerance of + / -10% of the values ​​specified in Table 1, wherein the constriction distribution (Do) reduces aerodynamic losses and improves aerodynamic loads on the blade (37). Guide vane (36) according to claim 4 or 5, wherein a trailing edge (46) of the blade (37) has a projection (500) at about 50% of its span. Guide vane (36) according to claim 6, wherein the trailing edge (46) of the blade (37) has an offset of about 0 at about 0% span, about 100% at about 50% span and about 0 at 100% span. Guide vane (36) according to claim 6 or 7, wherein the trailing edge (46) of the blade (37) has an offset as defined by values ​​specified in Table 2. Guide vane (36) according to any one of claims 4 to 8, wherein the blade (37) has a thickness distribution (Tmax / Tmax_midspan) as defined by values ​​specified in Table 3, and / or the blade (37) has a dimensionless thickness distribution according to values ​​specified in Table 4, and / or the blade (37) has a dimensionless axial chord distribution according to values ​​specified in Table 5.

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