External case heater for an angle of attack sensor
A heating apparatus for use in an AoA sensor is described herein. The heating apparatus includes a heating element bonded to a support element. The support element is configured to be attachable to and removable from the AoA sensor. The heating element may receive an electrical current, causing the temperature of the heating element to increase. The temperature increase is designed to reduce the probability that ice forms in certain locations of the AoA sensor.
1. An angle of attack sensor, comprising:
a rotatable mount;
an airfoil-shaped body coupled to the rotatable mount;
an outer casing defining an inner volume;
a faceplate extending over the outer casing and configured to partially receive the rotatable mount, wherein a space is defined between the rotatable mount and an outer surface of the faceplate; and
a heating apparatus disposed in the inner volume of the outer casing, and including:
a support element coupled to the outer casing, at least a portion of the support element abutting a portion of the outer casing;
a heating element coupled to the support element;
a flange independent of the support element and coupled to the heating element, the flange abutting an inner surface of the faceplate and configured to heat the space between the rotatable mount and the outer surface of the faceplate;
a control thermostat configured to receive a temperature input and allow current to flow through the heating element at or below a first temperature and reduce current flow through the heating element at or above a second temperature.
2. The angle of attack sensor of claim 1 , wherein the support element comprises a metal collar.
3. The angle of attack sensor of claim 1 , wherein a portion of the heating element is disposed on a portion of the flange.
4. The angle of attack sensor of claim 1 , wherein the support element comprises a hinge to allow a first end of the support element to be rotated from a second end of the support element.
5. The angle of attack sensor of claim 1 , wherein the support element is sized to allow a space between a first end of the support element and a second end of the support element to indicate a proper installation of the support element.
6. The angle of attack sensor of claim 5 , further comprising a fastener for releasably affixing the first end of the support element to the second end of the support element.
7. The angle of attack sensor of claim 1 , further comprising a polyimide bond between the support element and the heating element to directly bond the support element to the heating element.
8. The angle of attack sensor of claim 1 , wherein the heating element is comprised of one or more of polyacetylene, polypyrrole, polyaniline, and p-phenylene vinylene, or copolymers of polyacetylene, polypyrrole, polyaniline, and p-phenylene vinylene.
9. The angle of attack sensor of claim 1 , wherein the heating element comprises metal.
10. An angle of attack sensor system for an aircraft, comprising:
an angle of attack sensor comprising:
an airfoil-shaped body affixed to a rotatable mount;
a casing defining an inner volume; and
a faceplate extending over the outer casing and configured to partially receive the rotatable mount, wherein a space is defined between the rotatable mount and an outer surface of the faceplate; and
a heating apparatus disposed in the inner volume of the outer casing and configured to reduce ice formation in the space between the rotatable mount and the outer surface of the faceplate, the heating apparatus comprising:
a support element configured for releasable engagement with outer casing of the angle of attack sensor,
a heating element bonded to the support element to form a composite structure,
a flange independent of the support element and coupled to the heating element, the flange abutting an inner surface of the faceplate, and
a control thermostat configured to receive a temperature input and allow current to flow through the heating element at or below a first temperature and reduce current flow through the heating element at or above a second temperature.
11. The angle of attack sensor system of claim 10 , wherein the support element comprises a metal collar.
12. The angle of attack sensor of system claim 10 , wherein the support element comprises a hinge to allow a first end of the support element to be rotated from a second end of the support element.
13. The angle of attack sensor system of claim 12 , further comprising a fastener for releasably affixing the first end of the support element to the second end of the support element.
14. The angle of attack sensor system of claim 10 , further comprising a polyimide bond between the support element and the heating element to directly bond the support element to the heating element.
15. The angle of attack sensor system of claim 10 , wherein the heating element is comprised of one or more of polyacetylene, polypyrrole, polyaniline, and p-phenylene vinylene, or copolymers of polyacetylene, polypyrrole, polyaniline, and p-phenylene vinylene.
16. The angle of attack sensor system of claim 10 , further comprising insulation to reduce an amount of heat lost from the heating apparatus to the environment, wherein the insulation comprises a heat reflective metal, ceramic, glass fiber sheet/matting, silica, mica, glass wool, asbestos, silk wool, or thermally insulative polymers.
17. The angle of attack sensor of claim 1 , in which the flange comprises a lateral portion aligned with the support element and a radial portion extending radially past the support element, the lateral and radial portions of the flange defining a heat transfer surface area abutting the inner surface of the faceplate.
18. The angle of attack sensor system of claim 10 , in which the flange comprises a lateral portion aligned with the support element and a radial portion extending radially past the support element, the lateral and radial portions of the flange defining a heat transfer surface area abutting the inner surface of the faceplate.