Fluidic actuator

Patent metadata

Field	Value
Publication number	US-9689400-B2
Application number	US-201314031644-A
Country	US
Kind code	B2
Filing date	Sep 19, 2013
Priority date	Oct 22, 2012
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A fluidic actuator comprising: a fluid nozzle for delivering fluid and a tube having an open end and a closed end, the open end spaced from the fluid nozzle. Also a pair of electrodes mounted in the tube and spaced apart to create a spark gap therebetween. A voltage source is arranged to supply a voltage across the pair of electrodes wherein the voltage causes plasma formation in the spark gap thereby shortening the effective length of the tube.

First claim

The invention claimed is:

1. A fluidic actuator comprising:
a fluid nozzle for delivering fluid;
a tube having an open end and a closed end, the open end spaced from the fluid nozzle,
a pair of electrodes mounted in the tube and spaced apart to create a spark gap therebetween; and
a voltage source arranged to supply a voltage across the pair of electrodes wherein the voltage causes plasma formation in the spark gap thereby shortening the effective length of the tube.

2. A fluidic actuator as claimed in claim 1 wherein the pair of electrodes are axially aligned and circumferentially spaced.

3. A fluidic actuator as claimed in claim 1 wherein the pair of electrodes are circumferentially aligned and axially spaced.

4. A fluidic actuator as claimed in claim 1 comprising more than one pair of electrodes.

5. A fluidic actuator as claimed in claim 1 comprising more than one voltage source.

6. A fluidic actuator as claimed in claim 1 further comprising a controller connected to the voltage source.

7. A fluidic actuator as claimed in claim 1 wherein the voltage source is arranged to supply a voltage of 1 kV to 20 kV.

8. A fluidic actuator as claimed in claim 7 wherein the voltage source is controlled by a square wave function.

9. A fluidic actuator as claimed in claim 1 wherein the tube has a circular cross-section.

10. A fluidic actuator as claimed in claim 1 wherein the tube has a rectangular cross-section.

11. A fluidic actuator as claimed in claim 1 wherein the tube has a constant diameter for all its axial length.

12. A fluidic actuator as claimed in claim 1 wherein the tube has a different diameter at points along its axial length.

13. A rotor sub-assembly comprising a rotor having an array of blades, a casing segment surrounding the rotor blades and a fluidic actuator as claimed in claim 1 , the fluidic actuator arranged to supply fluid to a clearance control arrangement.

14. A seal arrangement comprising the fluidic actuator as claimed in claim 1 comprising a seal segment a rotating component against which the seal acts and a clearance control arrangement arranged to receive fluid from the fluidic actuator.

15. A gas turbine engine comprising a fluidic actuator as claimed in claim 1 .

16. A gas turbine engine comprising a rotor sub-assembly as claimed in claim 13 .

17. A gas turbine engine comprising a seal arrangement as claimed in claim 14 .

Assignees

• Rolls Royce Plc

Inventors

• Bacic Marko
• Daniel Ronald William

Classifications

• F05D2270/62

  Electrical actuators · CPC title

• F01D11/06 Primary

  Control thereof · CPC title

• F01D11/10

  using sealing fluid, e.g. steam · CPC title

• F01D11/20

  Actively adjusting tip-clearance · CPC title

• F04D29/16 Primary

  between pressure and suction sides · CPC title