Axial turbomachine compressor inner shell

Patent metadata

Field	Value
Publication number	US-10132188-B2
Application number	US-201514755223-A
Country	US
Kind code	B2
Filing date	Jun 30, 2015
Priority date	Jun 30, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

The present application relates to an axial turbomachine gaseous flow-guiding element, such as a compressor inner shroud or vane. The element includes a plasma generator including: a layer of dielectric material with a guiding surface in contact with the gaseous flow, a first electrode placed in the guiding surface, and a second electrode electrically isolated from the first electrode by means of the dielectric layer. The plasma generator drives the gaseous flow along the guiding surface from the first electrode to the second electrode and includes a third electrode covered by the dielectric layer and electrically connected to the second electrode, so as to participate in the generation of the plasma in combination with the first electrode and the second electrode, the second electrode being closer to the guiding surface than the third electrode.

First claim

I claim:

1. A guiding element of a gaseous flow of a turbomachine, comprising:
a plasma generator;
a guiding surface of the gaseous flow of the turbomachine;
a layer of dielectric material in contact with the gaseous flow of the turbomachine and partially forming the guiding surface;
a first electrode placed in the guiding surface;
a second electrode electrically isolated from the first electrode by the dielectric layer, the plasma generator being configured so as to drive the gaseous flow along the guiding surface from the first electrode towards the second electrode by a driving plasma; and
a third electrode electrically connected to the second electrode so as to participate in the generation of the driving plasma in combination with the first electrode and the second electrode;
wherein the third electrode is covered by the dielectric layer and the second electrode is closer to the guiding surface than the third electrode, and the first electrode and the second electrode partially forming the guiding surface and being biased at different electric potentials.

2. The guiding element in accordance with claim 1 , wherein the dielectric layer comprises:
a surface opposite the guiding surface with respect to the thickness of the dielectric layer, the third electrode being disposed on the opposite surface.

3. The guiding element in accordance with claim 1 , wherein the third electrode is disposed between the second electrode and the first electrode in the flow direction of the gaseous flow.

4. The guiding element in accordance with claim 1 , wherein the gaseous flow is a primary annular flow of the turbomachine, the first electrode being disposed upstream from the primary flow and the second electrode being disposed downstream from the primary flow.

5. The guiding element in accordance with claim 1 , wherein the second electrode and the third electrode are electrically isolated from the gas flow and from the first electrode by the dielectric layer.

6. The guiding element in accordance with claim 1 , wherein the second electrode is encased in the dielectric layer.

7. The guiding element in accordance with claim 1 , wherein the layer of dielectric material comprises:
fibres so as to form a composite material.

8. The guiding element in accordance with claim 1 , wherein the second electrode and the third electrode are connected together by a conducting element and to the earth potential of the plasma generator, the conducting element being a wire.

9. The guiding element in accordance with claim 1 , being configured to define an inner shroud comprising:
outer annular surface for guiding an annular flow; and
an inner annular surface;
wherein the first electrode and the second electrode are disposed at the downstream edge, the first electrode being in the inner surface, and the second electrode being in the outer surface of the shroud.

10. The guiding element in accordance with claim 1 , being configured to define a turbomachine vane, wherein the driving plasma drives the flow in a circumferential direction toward the vane.

11. An axial turbomachine compressor for compressing an annular flow flowing axially therethrough, comprising:
a rotor with several rows of blades and a stator with several rows of vanes embracing the blade rows, the stator comprising:
a plasma generator; and
at least one of the vanes exhibiting a guiding surface of the annular flow said guiding surface comprising a leading edge, a trailing edge, a pressure face, and a suction face which extend from the leading edge to the trailing edge, the plasma generator comprising:
a layer of dielectric material partially forming the guiding surface in order to guide the compressed annular flow;
a first electrode placed in the guiding surface and partially forming the guiding surface;
a second electrode electrically isolated from the first electrode by the dielectric layer, the plasma generator being configured so as to drive the annular flow along the guiding surface from the first electrode towards the second electrode by means of a driving plasma; and
a third electrode which is electrically connected to the second electrode so as to participate in the generation of the driving plasma in combination with the first electrode and the second electrode;
wherein the third electrode is covered by the dielectric layer and the second electrode is closer to the guiding surface than the third electrode, wherein the first electrode and the second electrode being arranged on the suction face of the vane and the third electrode being disposed on the pressure side of the vane.

12. The axial turbomachine compressor in accordance with claim 11 , wherein the middle of the chord of the vane is disposed at the first electrode.

13. The axial turbomachine compressor in accordance with claim 11 , wherein the second electrode forms the trailing edge of the vane, and the vane comprises:
a metal leading edge which is electrically isolated from the first electrode, the second electrode and the third electrode by the dielectric layer.

14. An axial turbomachine exhibiting a primary annular flow and a secondary annular flow around the primary annular flow, the turbomachine comprising:
at least one shroud with a guiding surface of the primary flow and which is formed of several segments separated by separating gaps; and
a plasma generator comprising:
a layer of dielectric material in contact with the primary flow of the turbomachine and partially forming the guiding surface;
a first electrode placed in the guiding surface and partially forming the guiding surface;
a second electrode electrically isolated from the first electrode by the dielectric layer, the plasma generator being configured so as to drive the annular flow along the guiding surface from the first electrode towards the second electrode by a driving plasma; and
a third electrode which is electrically connected to the second electrode so as to participate in the generation of the driving plasma in combination with the first electrode and the second electrode, the driving plasma crossing over the third electrode;
wherein the third electrode is isolated of the primary flow by the dielectric layer and the second electrode is closer to the guiding surface than the third electrode, and the first electrode and the second electrode being disposed on either side of one of the separating gaps, the third electrode passing through one of the separating gaps.

15. The axial turbomachine in accordance with claim 14 , further comprising: a power supply device for supplying power to the first electrode in order to generate the driving plasma.

16. The axial turbomachine in accordance with claim 14 , wherein the shroud includes an upstream edge and a downstream edge, the first electrode being disposed at the upstream edge and the second electrode being disposed at the downstream edge.

17. The axial turbomachine in accordance with claim 14 , wherein the guiding surface is an outer guiding surface, the first electrode and the second electrode are disposed on the outer guiding surface of the shroud.

18. The axial turbomachine in accordance with claim 14 , wherein at least one of the first electrode, the second electrode and the third electrode is axially facing the rotor.

Assignees

• Techspace Aero Sa
• Safran Aero Boosters Sa

Inventors

• Hiernaux Stéphane

Classifications

• Y02T50/672

  Cross-Sectional Technologies · mapped topic

• F01D11/20

  Actively adjusting tip-clearance · CPC title

• F01D9/041

  using blades (F01D5/148 takes precedence) · CPC title

• F01D5/145 Primary

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

• F01D9/04

  forming ring or sector · CPC title