GAS TURBINE BLADE

Abstract

The present invention relates to a blade for a gas turbine, in particular of an aircraft engine, having a blade airfoil, which has a blade-root-side first profile section and a blade-tip-side second profile section, which is spaced apart from the first profile section in a radial direction, from the first profile section to the second profile section, by a blade airfoil height, wherein a stagger angle of the blade airfoil changes with a height in the radial direction over the first profile section at least over certain portions, wherein, in a first region between a first height and a second, greater height, the change in the stagger angle over the height does not decrease with increasing height at least over certain portions.

Claims

1. A blade for a gas turbine of an aircraft engine, comprising: a blade airfoil, which has a blade-root-side first profile section and a blade-tip-side second profile section, which is spaced apart from the first profile section in a radial direction, from the first profile section to the second profile section, by a blade airfoil height, wherein a stagger angle of the blade airfoil changes with a height in the radial direction over the first profile section at least over certain portions, wherein, in a first region between a first height and a second, greater height, the change in the stagger angle over the height does not decrease with increasing height at least over certain portions, and in an adjoining second region between the second height and a third, greater height, the change in the stagger angle decreases with increasing height at least over certain portions, the first height representing at least 30% and at most 60% of the blade airfoil height, the second height representing at least 50% and at most 80% of the blade airfoil height, and the third height representing at least 80% and at most 100% of the blade airfoil height.

2. The blade according to claim 1, wherein the change in the stagger angle over the height in an end region between 90% and 100% of the blade airfoil height is negative at least over certain portions.

3. The blade according to claim 1, wherein the blade airfoil in a reflex region of the height between an initial height, which represents at least 80% of the blade airfoil height, and the blade airfoil height has a reflexed portion at least over certain portions.

4. The blade according to claim 3, wherein an inflection point of the reflexed portion in at least one profile section of the reflex region lies in a middle third of this profile section and/or is further distant from a trailing edge than in at least one profile section of the reflex region that is closer to the first profile section, and/or an inflection point of the reflexed portion arrives in the trailing edge in the case of the initial height.

5. The blade according to claim 1, wherein the stagger angle in an end region between 95% and 100% of the blade airfoil height is smaller at least over certain portions than a trailing edge angle.

6. The blade according to claim 1, wherein a profile center of gravity in at least one profile section of the second region is displaced with respect to the profile center of gravity in at least one profile section of the second region that is closer to the first profile section toward a suction side of the blade airfoil.

7. The blade according to claim 1, wherein at least one blade is configured and arranged in a rotating blade cascade or a guide vane cascade for a compressor stage or a turbine stage of a gas turbine of an aircraft engine.

8. The blade according to claim 7, wherein the at least one rotating blade cascade and/or the at least one guide vane cascade is configured and arranged in a compressor stage or a turbine stage for a gas turbine of an aircraft engine.

9. The blade according to claim 8, wherein at least one compressor stage and/or at least one turbine stage are configured and arranged in an aircraft engine gas turbine.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0027] Other advantageous further developments of the present invention ensue from the dependent claims and the following description of preferred embodiments. For this purpose and in part schematically:

[0028] FIG. 1 shows a profile section of a blade in accordance with an embodiment of the present invention;

[0029] FIG. 2 shows another profile section of the blade at greater height in the radial direction;

[0030] FIG. 3 shows a stagger angle β of the blade over the height R in the radial direction; and

[0031] FIG. 4 shows a meridional section of a part of a gas turbine with the blade.

DESCRIPTION OF THE INVENTION

[0032] FIG. 4 shows a meridional section of a part of a gas turbine in accordance with an embodiment of the present invention with a guide vane having a blade airfoil V, which is arranged on a housing Ge, and a rotating blade having a blade airfoil B, which is arranged on a rotor disk Ro.

[0033] LE.sub.V and LE.sub.B indicate an upstream leading edge, TE.sub.V and TE.sub.B a downstream trailing edge, P.sub.1,V and P.sub.1,B a blade-root-side first profile section, P.sub.2,V and P.sub.2,B a blade-tip-side second profile section, and R.sub.V and R.sub.B a radial direction from the first profile section P.sub.1,V and P.sub.1,B to the second profile section P.sub.2,V and P.sub.2,B, in which the second profile section is spaced apart from the first profile section by a blade airfoil height H.

[0034] The blade of FIGS. 1, 2 can be the guide vane with the blade airfoil V or the rotating blade with the blade airfoil B of FIG. 4.

[0035] Accordingly, in FIGS. 1, 2, the leading edge is indicated uniformly by LE, the trailing edge by TE. Ps and Ss in FIGS. 1, 2 indicate a pressure side and suction side, respectively, β indicates a stagger angle of the profile section or an angle between its profile chord Ch and the axial direction (see FIG. 4) parallel to the rotational axis A, Ca in FIG. 1 indicates the camber line or profile centerline of the profile section, and α.sub.LE and α.sub.TE indicate a leading edge angle and a trailing edge angle, respectively.

[0036] The stagger angle β of the profile section of FIG. 2 is smaller than the trailing edge angle α.sub.TE of the profile section.

[0037] FIG. 3 shows the course of the stagger angle β over the height R in the radial direction (see FIG. 4).

[0038] In this case, R.sub.1 indicates a first height over the first profile section, which represents at least 30% and at most 60% of the blade airfoil height H (see FIG. 4), R.sub.2 a second, greater height than the first profile section, which represents at least 50% and at most 80% of the blade airfoil height H, R.sub.3 a third, still greater height than the first profile section, which represents at least 80% and at most 100% of the blade airfoil height H, and R.sub.a an initial height over the first profile section, which, in the exemplary embodiment, represents 97% of the blade airfoil height H.

[0039] The stagger angle β of the blade airfoil changes over or with the height R in the radial direction at least over certain portions (β=β(R)), wherein this change dβ/dR in the stagger angle β over the height increases with increasing height in a first region [R.sub.1, R.sub.2] between the first and second heights R.sub.1, R.sub.2 and, in an adjoining second region [R.sub.2, R.sub.3], decreases with increasing height between the second and third height R.sub.2, R.sub.3 and is thereby negative in a blade-tip-side end region of the blade airfoil.

[0040] The profile section of FIG. 2 lies in a reflex region of the height between 97% and 100% of the blade airfoil height H. The profile section or its camber line or profile centerline Ca has a reflexed portion with an inflection point W, which, in the exemplary embodiment, coincides only coincidentally with a profile center of gravity SP.

[0041] The inflection point W lies in a middle third of the profile section. With decreasing height, it migrates toward the trailing edge and finally arrives at the lower end of the reflex region in this reflex region.

[0042] Although, in the preceding description, exemplary embodiments were explained, it is noted here that a large number of modifications are possible. Moreover, it is noted that the exemplary embodiments involve merely examples, which are not intended to limit the protective scope, the applications, and the construction in any way. Instead, the preceding description is intended to afford the person skilled in the art a guideline for the implementation of at least one exemplary embodiment, whereby diverse modifications, in particular in regard to the function and arrangement of the described component parts, can be made without leaving the protective scope as ensues from the claims and the combinations of features equivalent to these.