Aircraft propulsion system comprising a member covered with a grooved structure

Patent metadata

Field	Value
Publication number	US-11148787-B2
Application number	US-201716096496-A
Country	US
Kind code	B2
Filing date	Apr 24, 2017
Priority date	Apr 26, 2016
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

The invention concerns an aircraft propulsion system comprising at least one member ( 1, 3, 4, 8 ) in contact with a turbulent flow of a stream (F), characterised in that said member is covered, at least partially, by a piezoelectric structure (S) such as a piezoelectric film, said structure (S) comprising a grooved structure ( 5, 6, 7, 9 ) comprising a series of grooves, in contact with the flow of the stream, the grooves extending in the direction of flow of the stream, the grooved structure comprising at least one geometric parameter (h, s, w) configured to adapt depending on at least one parameter of the flow of the stream and/or an operating point of the propulsion system and/or an engine speed of the propulsion system.

First claim

The invention claimed is:

1. An aircraft propulsion system comprising:
at least one member in contact with a turbulent flow of a stream, wherein the at least one member is covered, at least partially, with a piezoelectric film comprising a grooved structure comprising a series of grooves, in contact with the flow of the stream, the grooves being formed by grooving a surface of the at least one member such that the grooves have a vertex that extends continuously in a flow direction of the stream in order to form longitudinal channels for the stream, the grooved structure comprising at least one geometric parameter configured to adapt as a function of at least one parameter of the stream flow and/or an operating point of the aircraft propulsion system and/or an engine speed of the aircraft propulsion system, the at least one geometric parameter being a height and a spacing between two vertices.

2. The aircraft propulsion system according to claim 1 , wherein the piezoelectric film is of the electroactive polymer type selected from a group consisting of PVDF, PVF2, PVF2-TFE, PMMA and a PZT ceramic.

3. The aircraft propulsion system according to claim 1 , wherein the structure further comprises a polarizing unit that polarizes the film by an alternating voltage source and conductive or semiconductive electrodes placed in contact with the film.

4. The aircraft propulsion system according to claim 1 , wherein the height is between 10 μm and 100 μm.

5. The aircraft propulsion system according to claim 1 , wherein the operating point of the aircraft propulsion system is: parking, shop-visit, cruise, or icing episode.

6. An aircraft comprising the aircraft propulsion system according to claim 1 .

7. The aircraft propulsion system according to claim 1 , wherein the grooves are longitudinal grooves.

8. The aircraft propulsion system according to claim 1 , wherein the piezoelectric film is selected from the following group: PVDF, PVF2, PVF2-TFE, PMMA or a PZT ceramic.

9. The aircraft propulsion system according to claim 1 , wherein each groove is formed of two walls that extend longitudinally in the flow direction with the vertex therebetween, and an angle between the two walls of the groove is between 15 degrees and 60 degrees.

10. The aircraft propulsion system according to claim 1 , wherein a peak to peak height of the grooves in a transverse direction to the flow direction is between 20 μm and 100 μm, and a peak height of the grooves in a direction orthogonal to the flow direction is between 10 μm and 100 μm.

11. The aircraft propulsion system according to claim 1 , wherein each groove is formed of two walls that extend longitudinally in the flow direction with the vertex therebetween, a peak to peak height of the grooves is between 20 μm and 100 μm, a peak height of the grooves is between 10 μm and 100 μm, and an angle between the two walls of the grooves is between 15 degrees and 60 degrees.

Assignees

• Safran

Inventors

• Goncalves Emilie
• Lanfant Nicolas Pierre
• Mandel Robin

Classifications

• B64D15/00 Primary

  De-icing or preventing icing on exterior surfaces of aircraft · CPC title

• B64D15/16

  by mechanical means, e.g. pulsating mats or shoes attached to, or built into, surface · CPC title

• F01D5/143

  Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour · CPC title

• B64C23/005 Primary

  by other means not covered by groups B64C23/02 - B64C23/08, e.g. by electric charges, magnetic panels, piezoelectric elements, static charges or ultrasounds · CPC title

• F05D2260/407

  through piezoelectric conversion · CPC title