Contouring a blade/vane cascade stage

Abstract

Disclosed is a blade/vane cascade segment of a blade/vane cascade of a turbomachine, which comprises at least two blade/vane elements defining an axial cascade width, and a stage with a stage surface, as well as a stage edge on the inflow side. The stage surface has an elevation extending up to the pressure side of a first blade/vane element and a depression extending up to the suction side of the other blade/vane. At least one highest point of the elevation and at least one lowest point of the depression each lie at least 30% and at most 60% of the axial cascade width downstream of the inflow edges of the blade/vane elements. In this case, the elevation and the depression each come close to the stage edge on the inflow side.

Claims

1. A blade/vane cascade segment of a blade/vane cascade of a turbomachine, comprising: at least two blade/vane elements, each defining an axial cascade width by their inflow and outflow edges; a stage having a stage surface and a stage edge, the stage edge being the leading edge on the inflow side; wherein the stage surface has an elevation extending up to the pressure side of a first blade/vane element and a depression extending up to the suction side of the other blade/vane element; wherein at least one highest point of the elevation and at least one lowest point of the depression each lie at least 30% and at most 60% of the axial cascade width downstream of the inflow edges of the blade/vane elements; and wherein the elevation and the depression each extend directly from the stage edge on the inflow side.

2. The blade/vane cascade segment according to claim 1, wherein axial positions of the at least one highest point of the elevation and of the at least one lowest point of the depression differ from one another by at most 10% of the axial cascade width.

3. The blade/vane cascade segment according to claim 1, wherein the at least one highest point of the elevation is arranged downstream of the at least one lowest point of the depression.

4. The blade/vane cascade segment according to claim 1, wherein the stage edge on the inflow side covers the elevation and/or the depression.

5. The blade/vane cascade segment according to claim 1, wherein the stage surface also has an additional elevation, which extends up to the suction side of the other blade/vane element.

6. The blade/vane cascade segment according to claim 5, wherein the additional elevation is arranged upstream of the depression.

7. The blade/vane cascade segment according to claim 5, wherein a highest point of the additional elevation lies at most 15% or even at most 10% of the axial cascade width downstream of the inflow edges of the blade/vane elements.

8. The blade/vane cascade segment according to claim 5, wherein the additional elevation has at least one highest point that lies on a boundary line of the stage surface to the suction side of the other blade/vane element.

9. The blade/vane cascade segment according to claim 1, wherein the blade/vane cascade is a guide vane cascade or a rotating blade cascade.

10. The blade/vane cascade segment according to claim 1, wherein the blade/vane cascade segment is used in a blade/vane cascade in a turbomachine.

11. The blade/vane cascade segment according to claim 1, wherein the blade/vane cascade segment and a side wall lying opposite to the stage of the blade/vane cascade segment bounds a channel of a turbomachine.

12. The blade/vane cascade segment according to claim 1, wherein a stage bounds the at least two blade/vane elements in a peripheral direction.

13. The blade/vane cascade segment according to claim 1, where at least one blade/vane cascade is used in a turbomachine.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) Preferred embodiment examples of the invention will be explained in more detail in the following based on drawings. It is understood that individual elements and components can also be combined in other ways than what is shown. Reference numbers for elements corresponding to one another are used in all of the figures and are not newly described for each figure.

(2) Herein, shown schematically:

(3) FIG. 1 shows a blade/vane cascade segment of an exemplary embodiment of the present invention in top view; and

(4) FIG. 2 shows a blade/vane cascade segment of an alternative exemplary embodiment of the present invention in top view.

DESCRIPTION OF THE INVENTION

(5) An exemplary, developed embodiment of a blade/vane cascade segment 1 according to the invention is shown schematically in FIG. 1 in top view (with radial direction of view). It comprises blade/vane elements 20, 30, each of which has a pressure side and a suction side, as well as a stage 10 according to the invention, with a stage edge 10a on the inflow side and a stage edge 10b on the outflow side (relative to the provided principal flow direction X). The stage can be designed in one part, or, for example, can be made of two parts (not shown); in particular, it can comprise two parts, and one of the blade/vane elements 20, 30 projects from each part.

(6) The blade/vane elements 20, 30 define an axial cascade width g by the distance between their inflow edges 23, 33 and their outflow edges 24, 34 at the stage surface, this width being measured in the axial principal flow direction X.

(7) The stage surface has an elevation 11 with a highest point 12 illustrated by contour lines in FIG. 1, extending up to the pressure side 21 of the one (first) blade/vane element 20. As can be seen from the contour lines, the blade/vane element 20 rests partially (namely in its front region) on the elevation 11.

(8) Furthermore, the stage surface has a depression 13 with a lowest point 14, again illustrated by contour lines in FIG. 1, extending up to the suction side 32 of the other (second) blade/vane element 30. Again, as can be seen from the contour lines, the blade/vane element 30 rests partially (namely in its front region) in the depression 13.

(9) In this case, the highest point 12 and the lowest point 14 lie in an intermediate strip Z of the stage surface. In the top view that is shown (thus actually in the projection in the radial direction onto the stage surface), the boundaries of the intermediate strip Z on the inflow side and on the outflow side each run parallel to the stage edge 10a on the inflow side. The boundary of the intermediate strip on the inflow side lies by a distance a and the boundary on the outflow side lies by a distance b downstream of the inflow edges 23, 33, of the blade/vane elements 20, 30; in this case, the following applies: a=0.3 g and b=0.6 g. All points in the intermediate strip Z (and, in particular, the highest point 12 of the elevation and the lowest point 14 of the depression) thus lie at least 30% and at most 60% of the axial cascade width downstream of the inflow edges of the blade/vane elements.

(10) As is characterized by the contour lines in the figure, both the elevation 11 as well as the depression 13 extend up to the stage edge 10a on the inflow side.

(11) The highest point 12 of the elevation 11 has an axial position 12a, and the lowest point 14 of the depression analogously has an axial position 14a. In the axial direction, these positions 12a, 14a, have a distance d from one another; according to an advantageous embodiment, d0.1 g applies, so that the named axial positions thus differ from one another by at most 10% of the axial cascade width g in the axial direction.

(12) FIG. 2 shows an alternative embodiment of a developed blade/vane cascade segment 1 according to the invention in top view (with radial direction of view). Like the blade/vane cascade segment 1 shown in FIG. 1, it comprises blade/vane elements 20, 30 and a stage 10 according to the invention with a stage surface and a stage edge 10a on the inflow side and a stage edge 10b on the outflow side (relative to the provided axial principal flow direction X).

(13) Like the blade/vane cascade segment 1 shown in FIG. 1, the stage surface of the blade/vane cascade segment 1 shown in FIG. 2 also has an elevation 11 with a highest point 12 extending up to the pressure side 21 of the one (first) blade/vane element 20 and a depression 13 with a lowest point 14 extending up to the suction side 32 of the other (second) blade/vane element 30. The highest point 12 of the elevation and the lowest point 14 of the depression both lie in the intermediate strip Z, which is defined by the distances a, b as described above; thus, each are arranged at least 30% and at most 60% of the axial cascade width g downstream of the inflow edges 23, 33 of the blade/vane elements 20, 30.

(14) In the exemplary embodiment shown in FIG. 2, the stage edge 10a on the inflow side covers the elevation 11 in a section 11a. The stage edge 10a on the inflow side thus also has a contour (not shown in FIG. 2), in which it has a local maximum in the region 11a (as a graph of a one-dimensional function).

(15) The blade/vane cascade segment 1 also has another elevation 15, which extends up to the suction side 32 of the second blade/vane element 30. In this case, the additional elevation 15 is arranged upstream of the depression 13.

(16) Disclosed is a blade/vane cascade segment 1, 1 of a blade/vane cascade of a turbomachine, which comprises at least two blade/vane elements 20, 30 defining an axial cascade width g, and a stage 10 with a stage surface as well as a stage edge 10a on the inflow side. The stage surface has an elevation 11, 11 extending up to the pressure side 21 of a first blade/vane element 20 and a depression 13, 13 extending up to the suction side 32 of the other blade/vane element 30. At least one highest point 12, 12 of the elevation 11, 11 and at least one lowest point 14, 14 of the depression 13, 13 each lie at least 30% and at most 60% of the axial cascade width g downstream of the inflow edges 23, 33 of the blade/vane elements 20, 30. In this case, the elevation 11, 11 and the depression 13, 13 each come close to the stage edge 10a on the inflow side.

(17) Also disclosed are a blade/vane cascade, a stage for a blade/vane cascade segment, a blade/vane channel bound in the peripheral direction U, and a turbomachine.

(18) It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be covered by the appended claims.