Hybrid acoustic and induction-heating systems and methods for impeding formation of ice

Patent metadata

Field	Value
Publication number	US-10137994-B2
Application number	US-201615183618-A
Country	US
Kind code	B2
Filing date	Jun 15, 2016
Priority date	Jun 15, 2016
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

An airfoil comprises a skin, comprising an external surface and an internal surface. The skin has a controlled region. The airfoil also comprises an interior space, formed by the skin. The airfoil additionally comprises a hybrid acoustic induction-heating system, configured to impede formation of ice on the external surface. The hybrid acoustic induction-heating system comprises induction coils and a control system. Each one of the induction coils has a portion, arranged sufficiently close to the internal surface to produce an eddy current within the controlled region. The control system is configured to generate inductive heat and traveling-wave acoustic pressure in the controlled region by supplying different phases of the alternating electrical current to the induction coils based, at least in part, on an ambient temperature of a layer of fluid flowing over the external surface.

First claim

What is claimed is:

1. An airfoil, comprising:
a skin, comprising an external surface and an internal surface, opposite the external surface, wherein the skin is magnetically and electrically conductive, and wherein the skin has a controlled region;
an interior space, formed by the skin, wherein the internal surface of the skin faces the interior space;
a leading edge along the external surface of the skin; and
a hybrid acoustic induction-heating system, configured to impede formation of ice on the external surface of the skin and comprising:
induction coils, located within the interior space, wherein each one of the induction coils, in which a phase of an alternating electrical current is flowing, has a portion, arranged sufficiently close to the internal surface of the skin to produce an eddy current within the controlled region of the skin, and wherein the portion of one of the induction coils is adjacent to the portion of at least another one of the induction coils; and
a control system, configured to generate inductive heat and traveling-wave acoustic pressure in the controlled region of the skin by supplying the phases of the alternating electrical current to the induction cons based, at least in part, on an ambient temperature of a layer of fluid flowing over the external surface of the skin, and wherein supplying the phases of the alternating electrical current comprises supplying different ones of the phases of the alternating electrical current to those of the induction coils having the portions that are adjacent to each other.

2. The airfoil according to claim 1 , wherein the portion of at least one of the induction coils is closer to the leading edge than the portions of all other ones of the induction coils and is positioned to heat the leading edge.

3. The airfoil according to claim 1 , further comprising a temperature sensor, configured to measure the ambient temperature of a layer of fluid flowing over the external surface of the skin.

4. The airfoil according to claim 1 , wherein the induction coils comprise at least three induction coils and wherein each of the phases of the alternating electrical current is unique.

5. The airfoil according to claim 1 , wherein each of the induction coils has a sheet form.

6. The airfoil according to claim 1 , wherein each of the induction coils has a volumetric form.

7. The airfoil according to claim 1 , wherein the portion of each induction coil is parallel to the skin.

8. The airfoil according to claim 1 , wherein the airfoil is selected from the group consisting of a wing, an erosion shield, an empennage, a horizontal stabilizer, a vertical stabilizer, a winglet, a turbine-engine inlet, an engine nacelle, and a turbine blade.

9. The airfoil according to claim 1 , wherein the skin comprises a nickel-iron alloy.

10. The airfoil according to claim 1 , wherein the skin has a thickness of less than 1 mm and greater than 0.001 mm.

11. The airfoil according to claim 1 , wherein the skin is ferromagnetic.

12. The airfoil according to claim 1 , wherein the skin has relative magnetic permeability of greater than 1,000 and less than 10,000,000.

13. The airfoil according to claim 1 , wherein the skin has Curie temperature less than 300° C. and greater then 50° C.

14. The airfoil according to claim 1 , further comprising at least one magnet, located within the interior space and configured to produce a steady-state magnetic field within the skin.

15. The airfoil according to claim 14 , wherein, at a location in the skin, the steady-state magnetic field, produced by at least the one magnet, is transverse to the eddy current induced by one of the phases of the alternating electrical current flowing in a corresponding one of the induction coils.

16. The airfoil according to claim 14 , wherein the steady-state magnetic field is transverse to the portions of the induction coils.

17. The airfoil according to claim 14 , wherein the steady-state magnetic field at a location at the internal surface of the skin is transverse to the internal surface at the location.

18. The airfoil according to claim 14 , wherein the steady-state magnetic field is transverse to a portion of the internal surface of the skin that is closest to the leading edge.

19. The airfoil according to claim 14 , wherein the steady-state magnetic field is parallel to a portion of the internal surface of the skin that is closest to the leading edge.

20. The airfoil according to claim 14 , wherein at least the one magnet is a permanent magnet.

21. The airfoil according to claim 14 , wherein at least the one magnet is an electromagnet.

22. The airfoil according to claim 14 , wherein at least the one magnet is a plurality of magnets within the interior space.

23. The airfoil according to claim 14 , wherein a magnitude of the steady-state magnetic field is greater than 0.1 T (tesla) and less than 100 T.

24. The airfoil according to claim 14 , wherein the phases of the alternating electrical current each generate an alternating magnetic field with an amplitude that is less than a magnitude of the steady-state magnetic field.

25. The airfoil according to claim 24 , wherein ratios of each of the amplitudes of the alternating magnetic fields to the magnitude of the steady-state magnetic field are less than 0.1 and greater than 0.0001.

26. The airfoil according to claim 1 , wherein the control system is configured to supply a direct electrical current to at least one of the induction coils to generate a steady-state magnetic field within the skin.

27. The airfoil according to claim 26 , wherein the steady-state magnetic field is transverse to the skin at the internal surface of the skin.

28. The airfoil according to claim 26 , wherein, at a location in the skin between the leading edge and a portion of the internal surface that is closest to the leading edge, the steady-state magnetic field is transverse to the leading edge.

29. The airfoil according to claim 26 , wherein, at a location in the skin between the leading edge and a portion of the internal surface that is closest to the leading edge, the steady-state magnetic field is parallel to the leading edge.

30. The airfoil according to claim 26 , wherein the control system comprises a power supply, configured to supply one of the phases of the alternating electrical current and to supply the direct electrical current to at least the one of the induction cods.

31. The airfoil according to claim 26 , wherein the control system is configured to supply the direct electrical current to all of the induction coils to generate the steady-state magnetic field within the skin.

32. The airfoil according to claim 26 , wherein a magnitude of the steady-state magnetic field is greater than 0.1 T (tesla) and less than 100 T.

33. The airfoil according to claim 26 , wherein the phases of the alternating electrical current each generate an alternating magnetic field with an amplitude that is less than a magnitude of the steady-state magnetic field.

34. The airfoil according to claim 33 , wherein ratios of the amplitudes of the alternating magnetic fields to the magnitude of the steady-state magnetic field are each less than 0.1 and greater than 0.0001.

35. The airfoil according to claim 26 , whe

Assignees

• Boeing Co

Inventors

• Hull John Ralph
• Tanielian Minas H

Classifications

• H05B6/105

  using a susceptor · CPC title

• H05B2214/02

  Heaters specially designed for de-icing or protection against icing · CPC title

• B64D15/12 Primary

  by electric heating (heating arrangements specially adapted for transparent or reflecting areas H05B3/84) · CPC title

• B64D15/163

  using electro-impulsive devices · CPC title