Ice protection device and method

Abstract

An ice protection device for an aircraft surface having a composite layer. The device comprises a layer of electrically conductive material configured to be located at an outer face of the composite layer and adapted to be heated by electromagnetic induction. The device also comprises a perimetric monophasic winding to heat an edge surrounding a delimited area of the electrically conductive layer, an inner monophasic or multiphasic winding to heat the inside of the delimited area of the perimetric monophasic winding, a control unit, to independently control the outer winding and the inner winding, the control unit being adapted to continuously operate the outer winding to avoid the formation of ice in the edge of the delimited area and also to operate the inner winding when the ice formed inside the delimited area is to be detached.

Claims

1. An ice protection device for an aircraft surface having a composite layer, the device comprising: a layer of electrically conductive material configured and located at an outer face of the composite layer and being heated by electromagnetic induction, a perimetric monophasic winding configured to heat an edge surrounding a delimited area of the electrically conductive layer, an inner monophasic or multiphasic winding configured for heating an inside of the delimited area of the electrically conductive layer defined by the perimetric monophasic winding, a control unit, for independently controlling the perimetric monophasic winding and the inner monophasic or multiphasic winding, said control unit being configured such that the control unit is adapted for continuously operating the perimetric monophasic winding to avoid a formation of ice in the edge of the delimited area and the control unit is also adapted for operating the inner monophasic or multiphasic winding when the ice formed inside the delimited area is to be detached.

2. The ice protection device according to claim 1, wherein the perimetric monophasic winding and the inner monophasic or multiphasic windings are placed at an inner face of the composite layer.

3. The ice protection device according to claim 1, further comprising a modular distribution, each module comprising a perimetric monophasic winding and at least one inner monophasic or multiphasic winding.

4. The ice protection device according to claim 1, wherein phases of the inner multiphasic winding are geometrically displaced between the phases.

5. The ice protection device according to claim 1, wherein currents feeding phases of the inner multiphasic winding are temporally displaced between the phases.

6. The ice protection device according to claim 1, wherein current flowing through each phase of the inner multiphasic winding is equal for each phase.

7. The ice protection device according to claim 1, wherein the inner multiphasic winding is biphasic.

8. The ice protection device according claim 7, wherein a first phase and a second phase of the biphasic winding are temporally displaced 90 from each other.

9. The ice protection device according to claim 1, wherein the layer of electrically conductive material is a metallic mesh.

10. The ice protection device according to claim 1, wherein the layer of electrically conductive material is formed by metallic particles.

11. The ice protection device according to claim 1, further comprising an adhesive layer located between the composite layer and the layer of electrically conductive material.

12. The ice protection device according to claim 1, further comprising an additional adhesive layer located on top of the layer of electrically conductive material.

13. The ice protection device according to claim 1, further comprising an additional paint layer on top of the layer of electrically conductive material.

14. An aircraft surface comprising a composite layer and an ice protection device for the aircraft surface, the device comprising: a layer of electrically conductive material configured and located at an outer face of the composite layer and being heated by electromagnetic induction, a perimetric monophasic winding configured to heat an edge surrounding a delimited area of the electrically conductive layer, an inner monophasic or multiphasic winding configured for heating an inside of the delimited area of the electrically conductive layer defined by the perimetric monophasic winding, a control unit, for independently controlling the perimetric monophasic winding and the inner monophasic or multiphasic winding, said control unit being configured such that the control unit is adapted to continuously operate the perimetric monophasic winding to avoid formation of ice in the edge of the delimited area and the control unit is also adapted to operate the inner monophasic or multiphasic winding when the ice formed inside the delimited area is to be detached.

15. An ice protection method for an aircraft surface comprising a composite layer and a layer of electrically conductive material configured and located at an external surface of the composite layer and adapted to be heated by electromagnetic induction, wherein the aircraft surface comprises: a perimetric monophasic winding configured to heat an edge surrounding a delimited area of the electrically conductive layer, an inner monophasic or multiphasic winding configured to heat an inside of the delimited area defined by the monophasic winding, the method comprising the steps of: continuously operating the perimetric monophasic winding by a control unit to avoid the formation of ice in the edge of the delimited area, and operating the inner monophasic or multiphasic winding when the ice formed in the area defined by the perimetric monophasic winding is to be detached.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. The drawings form an integral part of the description and illustrate preferred embodiments of the invention. The drawings comprise the following figures.

(2) FIG. 1 shows a schematic representation of a cross-section of the different layers of the aircraft surface having the ice protection device.

(3) FIG. 2 shows a schematic representation of an embodiment of a phase winding distribution module, having a perimetric monophasic winding and two inner biphasic windings.

(4) FIG. 3 shows a schematic perspective representation of an embodiment of the overall winding layout along an aerodynamic surface of an aircraft, four modules (four perimetric monophasic windings and four sets of inner biphasic windings).

(5) FIG. 4 shows a schematic perspective representation of the embodiment shown in FIG. 3 when the perimetric monophasic windings are operated.

(6) FIG. 5 shows a schematic perspective representation of the embodiment shown in FIG. 3 when the sets of inner biphasic windings are operated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) FIG. 2 shows an embodiment of the ice protection device object of the invention. More specifically it shows the following phase winding distribution:

(8) a perimetric monophasic winding (1) configured for heating the edge surrounding a delimited area of the electrically conductive layer (12),

(9) an inner biphasic winding (2, 3) located inside the delimited area defined by the outer phase winding (1) and having two phases (2, 3) with a phase difference from each other.

(10) FIG. 2 discloses two inner biphasic windings (2, 3) which are located inside the same perimetric monophasic winding (1) and having the same phase difference between both phases (2, 3). FIG. 3 discloses four perimetric monophasic windings (1), each perimetric monophasic windings (1) surrounding a set of inner biphasic windings (2, 3).

(11) The two phases (2, 3) of the inner biphasic winding (2, 3) are geometrically and temporally displaced from each other.

(12) The device comprises:

(13) a perimetric monophasic winding (1) configured for heating the edge surrounding a delimited area of the electrically conductive layer,

(14) an inner monophasic or multiphasic winding (2,3) configured for heating the inside of the delimited area of the electrically conductive layer defined by the perimetric monophasic winding,

(15) a control unit (4), for independently controlling the perimetric monophasic winding (1) and the inner monophasic or multiphasic winding (2,3), the control unit being configured such that it continuously operates the perimetric monophasic winding to avoid the formation of ice in the edge of the delimited area and such that it operates the inner monophasic or multiphasic winding when the ice formed in the delimited area has, or is, to be detached.

(16) The outer phase winding (1) of the disclosed embodiment comprises a squared shape and the phases (2, 3) of the set of inner biphasic windings comprises an elongated shape so as to cover the inside area of the outer phase winding (1). Additional biphasic windings (2, 3) could be arranged and a more uniform heating would be reached.

(17) Additionally, both first and second phases (2, 3) of each inner biphasic winding are overlapped such that the ascending phase of the second phase (3) is located inbetween the ascending and descending phases of the first phase (2).

(18) Moreover, the first phase (2) and the second phase (3) are temporally displaced in 90, such that at 0 it is the ascending phase of the first phase (2), at 90 the current ascending phase of the second phase (3), at 180 the descending phase of the first phase (2) and at 270 the descending phase of the second phase (3).

(19) Finally, the current flowing through both first and second phases has to be equal. All the first phases (2) are fed together and all the second phases (3) are also fed together.

(20) With the geometrical and temporal displacement the magnetic field generated in the CFRP laminate is uniform, as well as the current density and consequently the induced losses. The windings distribution allows the achievement of a controlled heating distribution and therefore a modular winding distribution is proposed.

(21) Another advantage is that as the above distribution is modular, understanding for a module the set formed by a perimetric monophasic winding (1) and at least an inner monophasic or multiphasic winding (2, 3) located inside.

(22) When the inner phase winding (2, 3) is operating, the ice is detached from the surface. Since the outer phase winding (1) is continuously operating, the formation of ice in the horizontal and vertical strips is avoided, hence dividing the ice formation into segments and limiting its maximum size.

(23) An additional advantage is that since the inner phase winding (2, 3) is operated in a pulsed way it is not necessary to have all modules fed at once and they can be fed sequentially, so that the peak power required is lowered.

(24) In order to achieve the metallic layer (12) in the CFRP laminate, two different methods can be used:

(25) Inclusion of a metallic mesh or foil.

(26) Projection of metallic particles.

(27) The thickness of such layer (12), when combined with the proposed winding arrangement, can be as low as 0.01 mm

(28) For the projection of metallic particles, depending on the metallic material used, it may be required to introduce an intermediate layer (11) between the CFRP laminate (10) and the metallic layer. This intermediate layer (11) can be an adhesive or a thermoplastic projected onto the CFRP laminate (10) surface. Projection of both the thermoplastic (11) and the metallic layer (12) is typically performed by high velocity oxygen fuel (HVOF) coating.

(29) Depending on the metallic material used and its thickness, an additional adhesive layer (13) may be required on top of the metallic layer (12), as shown in FIG. 1.

(30) For the inclusion of a metallic mesh or foil an adhesive layer (11) has to be included between the CFRP laminate (10) and the metallic layer (12).

(31) The metallic materials that can be used for such application are:

(32) Iron based alloys (e.g., AISI304, AISI316)

(33) Nickel

(34) Aluminum

(35) Additional layers (13) of non-conductive materials can be added on top of the metallic layer (12), such as paint, without modifying the composite panel's electromagnetic response.

(36) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.