Stator of an axial compressor stage of a turbomachine

Patent metadata

Field	Value
Publication number	US-9822795-B2
Application number	US-201213431427-A
Country	US
Kind code	B2
Filing date	Mar 27, 2012
Priority date	Mar 28, 2011
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

The present invention relates to a stator of an axial compressor stage of a turbomachine featuring a radially outer blade ring forming an outer ring surface, a radially inner blade ring forming an inner ring surface, and several stator blades connected to the blade rings. It is provided that the outer ring surface and/or the inner ring surface has at least in a partial area a changing radius relative to a central axis of the stator both in the axial direction and in the circumferential direction.

First claim

What is claimed is:

1. A stator of an axial compressor stage of a turbomachine, comprising:
a radially outer blade ring forming an outer ring surface,
a radially inner blade ring forming an inner ring surface,
a plurality of stator blades connected to the blade rings,
wherein at least one chosen from the outer ring surface and the inner ring surface has at least in a partial area a changing radius relative to a central axis of the stator both in an axial direction and in a circumferential direction,
wherein for at least one longitudinal section through at least one chosen from the radially outer blade ring and the radially inner blade ring, a resulting surface line between an axial start value and an axial end value has a steadily changing radius, and wherein the axial start value—in the axial direction—is positioned upstream of leading edges of the stator blades and wherein the axial end value—in the axial direction—is positioned downstream of trailing edges of the stator blades;
wherein the at least one chosen from the outer ring surface and the inner ring surface between the axial start value and the downstream leading edges of the stator blades, and also between the trailing edges of the stator blades and the downstream axial end value, includes a changing radius relative to the central axis of the stator in the circumferential direction;
wherein the changing radius includes a convex elevation with respect to a mean radius r 0 of the at least one chosen from the outer ring surface and the inner ring surface, wherein the convex elevation has a larger radius than the mean radius r 0 ;
wherein the convex elevation extends along a center line of the inter-vane passage an entire length from a position at 50% of an axial chord length of the stator vanes to a position at trailing edges of the stator vanes.

2. The stator in accordance with claim 1 , wherein, for at least one section through at least one chosen from the radially outer blade ring and the radially inner blade ring in a plane normal to the central axis, a resulting surface line in an area between two stator blades has a steadily changing radius.

3. The stator in accordance with claim 1 , wherein for at least one section through at least one chosen from the radially outer blade ring and the radially inner blade ring in a plane normal to the central axis, a resulting surface line in an area between two stator blades is asymmetrical.

4. The stator in accordance with claim 3 , wherein a ring surface between two adjacent stator blades is shaped such that adjoining a suction side of one of the two adjacent stator blades, the at least one chosen from the outer ring surface and the inner ring surface has higher radii than adjoining a pressure side of the other of the two adjacent stator blades.

5. The stator in accordance with claim 1 , wherein for at least one section through at least one chosen from the radially outer blade ring and the radially inner blade ring in a plane normal to the central axis, a resulting surface line in an area between two stator blades has a convex bulge having a larger radius than a mean radius r 0 of the at least one chosen from the outer ring surface and the inner ring surface.

6. The stator in accordance with claim 1 , wherein for at least one longitudinal section through at least one chosen from the radially outer blade ring and the radially inner blade ring, a resulting surface line has a convex bulge having a larger radius than a mean radius r 0 of the at least one chosen from the outer ring surface and the inner ring surface.

7. The stator in accordance with claim 1 , wherein at least one chosen from the inner ring surface and the outer ring surface is shaped such that in a direction of an axially rear face of at least one chosen from the outer blade ring and the inner blade ring, the at least one chosen from the inner ring surface and the outer ring surface first has a concave depression and then spaced from the concave depression, a convex elevation with respect to a mean radius r 0 of the at least one chosen from the outer ring surface and the inner ring surface, wherein the convex elevation has a larger radius than the mean radius r 0 and the concave depression has a smaller radius than the mean radius r 0 .

8. The stator in accordance with claim 1 ,
wherein a first surface line of a first section through at least one chosen from the radially outer blade ring and the radially inner blade ring in a plane normal to the central axis conforms to a mathematical function;
wherein at least one second surface line of a second section through the at least one chosen from the radially outer blade ring and the radially inner blade ring adjacent to the first section in a plane normal to the central axis is defined by a same mathematical function as the first surface line, but having at least one chosen from a different phase position and a different amplitude relative to the first surface line.

9. The stator in accordance with claim 1 , wherein a course of a radius of the at least one chosen from the inner ring surface and the outer ring surface is parameterized by at least one chosen from an amplitude and a phase position of one trigonometric function, with values for the at least one chosen from the amplitude and phase position depending on a circumferential angle and an axial position with respect to the stator.

10. The stator in accordance with claim 9 , wherein the trigonometric function is a sine function or a cosine function.

11. The stator in accordance with claim 1 , wherein at least one chosen from the inner ring surface and the outer ring surface has a same three-dimensional contour between each adjacent pair of stator blades of the stator.

12. The stator in accordance with claim 1 , wherein the radially outer blade ring is part of a compressor casing.

13. The stator in accordance with claim 1 , wherein the axial start value is at an axial front face of the blade ring and the axial end value is at an axial rear face of the blade ring.

14. The stator in accordance with claim 1 , wherein the at least one chosen from the outer ring surface and the inner ring surface is shaped in a complete area between two stator blades to have, in a direction of an axially rear face of the blade ring, first a concave depression and then a convex elevation with respect to a mean radius r 0 of the at least one chosen from the outer ring surface and the inner ring surface, wherein the convex elevation has a larger radius than the mean radius r 0 and the concave depression has a smaller radius than the mean radius r 0 .

15. The stator in accordance with claim 1 , wherein the convex elevation includes a portion positioned between approximately 50-70% axial chord length of the stator vanes, and wherein a most elevated portion of the convex elevation at any axial position between the approximately 50-70% axial chord length of the stator vanes is positioned between but spaced away from opposing sides of the two adjacent stator blades.

16. The stator in accordance with claim 15 , wherein the resulting surface line further includes a concave depression having a smaller radius than the mean radius r 0 circumferentially positioned between the convex elevation and at least one of the opposing sides of the two adjacent stator blades between the approximately 50-70% axial chord length of the stator vanes.

17. The stator in accordance with claim 15 , wherein the resulting surface line further includes a concave depression having a smaller radius than the mean radius r 0 circumferentially positioned between the convex el

Assignees

• Johann Erik
• Heinichen Frank
• Rolls Royce Deutschland Ltd & Co Kg

Inventors

• Johann Erik
• Heinichen Frank

Classifications

• F04D29/547

  having a special shape in order to influence fluid flow · CPC title

• F01D9/04

  forming ring or sector · CPC title

• F04D29/522

  especially adapted for elastic fluid pumps · CPC title

• F05D2220/3216

  for a special compressor stage · CPC title

• F05D2250/70

  Shape · CPC title