BLADE OR GUIDE VANE WITH RAISED AREAS

Abstract

The invention relates to a blade or vane, particularly of a turbine stage of a gas turbine, in particular of an aircraft gas turbine, having a blade or vane root and a blade or vane element joined to the blade or vane root, wherein the blade or vane element has a pressure side and a suction side, and wherein the blade or vane root has at least one raised region on its radial outer side facing the blade or vane element. It is proposed according to the invention that the blade or vane has a first raised region on the pressure side and a second raised region on the suction side, wherein the highest point of the first raised region is disposed essentially directly adjacent to the pressure side, and the highest point of the second raised region is disposed essentially directly adjacent to the suction side.

Claims

1. A blade or vane of an aircraft gas turbine, comprising: a blade or vane root and a blade or vane element joined to the blade or vane root, wherein the blade or vane element has a pressure side and a suction side, and wherein the blade or vane root has at least one raised region on its radial outer side facing the blade or vane element, wherein the blade or vane has a first raised region on the pressure side and a second raised region on the suction side, wherein a highest point of the first raised region is disposed essentially directly adjacent to the pressure side, and a highest point of the second raised region is disposed essentially directly adjacent to the suction side.

2. The blade or vane according to claim 1, wherein the highest point of the first raised region and the highest point of the second raised region lie in a front or leading one-half of an axial distance in the direction of flow, wherein the axial distance is a projection of a chord, which joins a leading edge region and a trailing edge region of the blade or vane element.

3. The blade or vane according to claim 2, wherein the highest point of the second raised region lies in a front or leading first one-fourth of the axial distance.

4. The blade or vane according to claim 2, wherein the highest point of the first raised region lies in a second one-fourth of the axial distance.

5. The blade or vane according to claim 1, wherein the blade or vane is a rotating blade or a guide vane.

6. The blade or vane according to claim 1, wherein a plurality of rotating blades is disposed next to one another in the peripheral direction and configured and arranged in a rotor having a rotor disk.

7. the blade or vane according to claim 6, wherein the rotating blades are joined to the rotor disk in form-fitting manner by means of their rotating blade root.

8. The blade or vane according to claim 6, wherein the rotating blades and the rotor disk are integrally joined to one another.

9. The blade or vane according to claim 6, wherein at least one rotor is configured and arranged in an aircraft gas turbine.

Description

[0019] In FIG. 1, two rotating blades 10 with their respective blade element 11 are visible, each of which has a suction side 12 and a pressure side 14. The two rotating blades 10 or blade elements 11 are disposed next to one another at a distance UA in the peripheral direction UR. In this case, the two rotating blades 10 can be joined together integrally in one piece via a common radially inner platform, for example, by way of a casting process; thus they can form a part of a rotating blade cluster; or alternatively, they can also be separated from one another by way of a gap in the radially inner platform, which is not shown in the schematic figure, and thus they can particularly be separately manufactured individual rotating blades. A flow channel 16 is formed between the two rotating blades 10, and the fluid, in particular hot gas of a gas turbine flows through this channel in the main flow direction SR which is essentially parallel to the axial direction AR. The rotating blades 10 are preferably disposed in an annular channel conveying hot gas of a turbine stage, particularly a low-pressure turbine stage, of a gas turbine.

[0020] Contour lines 18 are drawn schematically and in a simplified manner on the pressure side 14 for the rotating blade 10 that is shown at the top of the figure. These contour lines represent a first raised region 20. Proceeding from a base level, the so-called ideal annular space, the raised region 20 rises between the two rotating blades 10 up to the pressure side 14. The first raised region 20 has a highest point 22 which, in the case of the pressure side 14, is disposed, in particular essentially, directly adjacent to the pressure side 14. Expressed in another way, it can also be stated that the first raised region 20 transitions into the pressure side 14 or contacts the pressure side 14.

[0021] For the lower rotating blade 10, a blade chord 28 is shown by the dotted line, which conceptually joins a leading edge 30 and a trailing edge 32 of the rotating blade 10. The projection of this blade chord 28 onto the axial direction AR forms the axial length AL of the rotating blades 10, which can also be called the axial distance.

[0022] One-half of the axial length HAL and one-fourth of the axial length VAL are depicted qualitatively by two dot-dash lines HAL and VAL running in the peripheral direction UR. Expressed in another way, one can also state that VAL is equal to 0.25×AL and that HAL is equal to 0.5×AL.

[0023] As can be seen from the illustration, it is preferred that the highest points 22, 26 of the first raised region 20 and the second raised region 24, when referred to the direction of flow SR (or axial direction AR), are disposed in the front or leading half. The highest points 22, 26, when referred to the axial length AL, thus have a position that is equal to or less than 0.5×AL. The highest point 26 of the second raised region 24 can also lie in the first one-fourth of the axial length AL; thus, in particular, it can assume a position that is less than VAL, although this is not shown in the drawing. Advantageously, there are also combinations in which the highest point 22 of the first raised region 20 lies between VAL and HAL, and the highest point 26 of the second raised region 24 is less than VAL.

[0024] For the first raised region 20, the highest point 22 can lie, in particular, in the region between VAL and HAL. The position of the highest point 22 is thus equal to or less than HAL and greater than or equal to VAL. The second raised region 24 is disposed within the front or leading half of the suction side 12. Expressed in another way, the complete second raised region 24 extends maximally up to one-half of the axial length HAL.

[0025] Due to the raised regions 20, 24 presented here, which are dimensioned or disposed with respect to the axial length AL of the rotating blades 10, the static pressure field on the side walls and on the blades in the edge region can be influenced so that secondary flows (channel eddies) can be reduced. Flow losses can be reduced thereby and the inflow of fluid or hot gas to a downstream blade cascade can be improved.

[0026] Although the invention has been explained in the figures only with respect to a rotating blade, raised regions can also be provided in an analogous way to a guide vane. Further, it is also conceivable that a radially outer shroud has raised regions in an analogous way.

LIST OF REFERENCE SYMBOLS

[0027] 10 (Rotating) blade [0028] 11 Blade element [0029] 12 Suction side [0030] 14 Pressure side [0031] 16 Flow channel [0032] 18 Contour line [0033] 20 First raised region [0034] 22 Highest point [0035] 24 Second raised region [0036] 26 Highest point [0037] 28 Chord [0038] 30 Leading edge [0039] 32 Trailing edge [0040] AL Axial length [0041] AR Axial direction [0042] HAL One-half axial length [0043] SR Direction of flow [0044] UA Distance in the peripheral direction [0045] UR Peripheral direction [0046] VAL One-fourth axial length