Blade of a row of rotor blades or stator blades for use in a turbomachine

Patent metadata

Field	Value
Publication number	US-9638040-B2
Application number	US-201214348845-A
Country	US
Kind code	B2
Filing date	Sep 28, 2012
Priority date	Sep 29, 2011
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

The present invention relates to a blade of a row of rotor blades or stator blades for use in a turbomachine, with the blade being designed with a substantially convex suction side and a substantially concave pressure side as well as with a leading edge, onto which the flow passes, and a trailing edge, away from which the flow passes. The blade has at least one contour recess provided on at least one of the blade sides including the suction side and the pressure side, wherein the contour recess includes a step edge, a contour corner and a flank face provided between the step edge and the contour corner. The contour recess extends over at least a part of the profile depth and/or the profile height of the blade.

First claim

What is claimed is:

1. A blade of a row of rotor blades or stator blades for use in a turbomachine, comprising:
a convex suction side,
a concave pressure side′
a leading edge, onto which a flow passes, and
a trailing edge, the flow passing away from the trailing edge,
at least one contour recess provided on at least one chosen from the suction side and the pressure side, wherein the contour recess includes,
a step edge,
a contour corner, and
a flank face provided between the step edge and the contour corner,
wherein the contour recess extends over at least a part of a profile depth and a profile height of the blade and
wherein the step edge extends, at least one point of its course of the step edge, obliquely to a meridional flow including a plurality of meridional flow lines around the blade, such that along one of the meridional flow lines passing over the step edge there is a contour receding in a meridional flow direction,
wherein the step edge has a starting point and a downstream end point spaced apart by a finite meridional distance,
wherein the step edge always crosses meridional flow lines at either a negative slope or positive slope, such that the step edge continuously gets closer to only one of a radially inner main flow path boundary and a radially outer main flow path boundary when proceeding in a downstream direction.

2. The blade in accordance with claim 1 , wherein the course of the step edge is provided by contour points of the blade having a greatest convex curvature of the blade contour in a vicinity of the contour recess, and a course of the contour corner is provided by contour points of the blade having a greatest concave curvature of the blade contour in the vicinity of the contour recess.

3. The blade in accordance with claim 1 , wherein the blade, in a meridional plane established by an axial coordinate x and a radial coordinate r is overflown by a family of meridional flow lines M(i), wherein
in a middle of a main flow path between the radially inner main flow path boundary and the radially outer main flow path boundary, a mean meridional flow line is provided, a course of which is defined by a connection of center points of circles inscribed in the main flow path,
inside the main flow path, a family of straight lines is alternatively provided, whose members are each positioned perpendicularly to the mean meridional flow line and end at the main flow path boundaries,
besides the mean meridional flow line, further meridional flow lines are defined by a connection of points an equal the same percentage subdivision of the straight lines between the main flow path boundaries,
the direction of one of the meridional flow lines defining the meridional coordinate, variable from point to point,
wherein the contour of the blade in at least one sectional plane through the blade established by a meridian-orthogonal coordinate and a circumferential coordinate has a step in a locally confined narrow area, and
the meridian-orthogonal coordinate is also variable from point to point and is defined as always being positioned perpendicularly to the mean meridional flow line.

4. The blade in accordance with claim 3 , wherein, when viewing the contour recess in a sectional plane established by a meridian-orthogonal coordinate and a circumferential coordinate, an auxiliary straight line defined by a point of the step edge, having a locally maximum convex contour curvature, and a point of the contour corner, having a locally maximum concave contour curvature, is inclined against a meridian-orthogonal direction by a steepness angle, with the steepness angle being measured from the auxiliary straight line on a shortest angular distance to the meridian-orthogonal direction, and wherein the steepness angle exceeds 10 degrees at at least one point of a course of the contour recess.

5. The blade in accordance with claim 1 , wherein the at least one contour recess includes a contour recess provided on the suction side of the blade.

6. The blade in accordance with claim 1 , wherein the step edge of the contour recess matches one of the meridional flow lines along at least a part of its course.

7. The blade in accordance with claim 1 , wherein the step edge of the contour recess starts in or downstream of a leading-edge plane of the blade, with the leading-edge plane being provided by rotation of the leading-edge line provided in a meridional plane in a circumferential direction about a center axis of the turbomachine.

8. The blade in accordance with claim 1 , wherein the step edge of the contour recess ends in or upstream of a trailing-edge plane of the blade, with the trailing-edge plane being provided by rotation of a trailing-edge line provided in a meridional plane in a circumferential direction about the center axis of the turbomachine.

9. The blade in accordance with claim 1 , wherein the contour recess is provided in a rim area of the blade, defined by radially inner or a radially outer 30% of a main flow path width in a vicinity of at least one of the radially inner and the radially outer main flow path boundaries.

10. The blade in accordance with claim 1 , wherein the step edge of the contour recess, ends directly at only one of the radially inner main flow path boundary, the radially outer main flow path boundary, and at an edge profile section of the blade, respectively.

11. The blade in accordance with claim 1 , wherein the flank face of the contour recess includes finite width ends directly at only one of the radially inner main flow path boundary, the radially outer main flow path boundary, and at an edge profile section of the blade, respectively.

12. The blade in accordance with claim 1 , wherein the contour recess is provided in a rim area, defined by a radially inner or a radially outer 30% of a main flow path width in a vicinity of a fixed blade end, at an inner end of a rotor blade, at an outer end of a rotor blade provided with an outer shroud, at an inner end of a stator blade provided with an inner shroud or at an outer end of a stator blade.

13. The blade in accordance with claim 1 , wherein the contour recess is provided in a rim area, defined by a radially inner or a radially outer 30% of a main flow path width in a vicinity of a free blade end, at an outer end of a rotor blade or at an inner end of a stator blade, with a gap being provided between an edge profile section of the free blade end and at least one of the radially inner main flow path boundary, and the radially outer main flow path boundary.

14. The blade in accordance with claim 1 , wherein the step edge of the contour recess in the meridional view is provided in a straight line or monotonously curved or has at least one curvature change.

15. The blade in accordance with claim 1 , wherein the contour recess is provided with the step edge, flank face and contour corner along an entire profile depth of the blade.

16. The blade in accordance with claim 1 , wherein a width of the flank face increases continuously in the meridional flow direction along a blade profile depth and correspondingly ends with a maximum of the width.

17. The blade in accordance with claim 1 , wherein the contour recess forms a ramp which in the meridional flow direction from a blade contour point within the main flow path leads to one of the radially inner main flow path boundary and a radially outer main flow path boundary.

18. The blade in accordance with claim 1 , wherein the step edge of the contour recess in a meridional plane established by an axial coordinate and a radial coordinate i

Assignees

• Rolls Royce Deutschland Ltd & Co Kg

Inventors

• Guemmer Volker

Classifications

• F05D2270/17

  to control boundary layer · CPC title

• F04D29/681

  especially adapted for elastic fluid pumps · CPC title

• F04D29/324

  Blades · CPC title

• F01D5/145

  Means for influencing boundary layers or secondary circulations (for compressors F04D29/68) · CPC title

• F01D5/141 Primary

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title