Air data probe including self-regulating thin film heater

Patent metadata

Field	Value
Publication number	US-11425797-B2
Application number	US-202016736953-A
Country	US
Kind code	B2
Filing date	Jan 8, 2020
Priority date	Oct 29, 2019
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

An air date probe includes a strut assembly extending from a base, and a tube assembly coupled to the strut assembly. One or both of the strut assembly and the tube assembly comprises a self-regulating thin film heating arrangement. The self-regulating thin film heating arrangement includes at least one circuit including a positive temperature coefficient (PTC) heating element connected in series with a negative temperature coefficient (NTC) heating element.

First claim

What is claimed is:

1. An air data probe, comprising:
a strut assembly extending from a base;
a tube assembly coupled to the strut assembly and extending therefrom; and
a self-regulating thin film heating arrangement in operable communication one or both of the strut assembly and the tube assembly, the self-regulating thin film heating arrangement comprising at least one circuit including a positive temperature coefficient (PTC) heating element having a first resistance connected in series with a negative temperature coefficient (NTC) heating element having a second resistance, a sum of the first and second resistances defining a total resistance of the self-regulating thin film heating arrangement,
wherein the first resistance corresponds to a targeted temperature threshold of the PTC heating element, and wherein the PTC heating element outputs a targeted maximum current that is set by the first resistance, and
wherein the NTC heating element dissipates a targeted amount of power according to the targeted maximum current.

2. The air data probe of claim 1 , wherein the strut assembly includes a strut self-regulating thin film heating arrangement and the tube assembly includes a tube self-regulating thin film heating arrangement connected in series with the strut self-regulating thin film heating arrangement.

3. The air data probe of claim 2 , wherein the tube self-regulating thin film heating arrangement includes a tube input node and a tube output node, and the strut self-regulating thin film heating arrangement includes a strut input node and a strut output node.

4. The air data probe of claim 3 , wherein the tube input node is in signal communication with a voltage source and the tube output node is in signal communication with the strut input node, and wherein the strut output node is in signal communication with a ground potential.

5. The air data probe of claim 4 , wherein the tube self-regulating thin film heating arrangement and the strut self-regulating thin film heating arrangement each include a carbon black/polymer composite heater forming the PTC heating element connected in series with a carbon nanotube/silicone heater forming the NTC heating element.

6. The air data probe of claim 5 , wherein at least one insulation layer is interposed between the carbon black/polymer composite heater and the carbon nanotube/silicone heater.

7. The air data probe of claim 6 , wherein the tube assembly comprises a cylindrical housing extending about a tube axis and an inner sleeve disposed within the cylindrical housing.

8. The air data probe of claim 7 , wherein the carbon black/polymer composite heater, the at least one insulation layer, and the carbon nanotube/silicone heater are cylindrically stacked between the inner sleeve and an inner surface of the cylindrical housing.

9. The air data probe of claim 6 , wherein the strut assembly comprises a strut housing and a strut sleeve disposed in the strut housing, the strut sleeve extending from the base to an upper strut portion located opposite the base.

10. The air data probe of claim 9 , wherein the carbon black/polymer composite heater, the at least one insulation layer, and the carbon nanotube/silicone heater are stacked between the strut housing and the strut sleeve.

11. The air data probe of claim 10 , wherein the carbon black/polymer composite heater, the at least one insulation layer, and the carbon nanotube/silicone heater extend from a first end disposed adjacent to the base and a second end disposed opposite the first end and adjacent to the upper strut portion.

12. A method of controlling heating of a self-regulating thin film heating arrangement included in an air data probe, the method comprising:
determining a targeted amount of power to be dissipated from the self-regulating thin film heating arrangement;
determining a targeted maximum current that achieves the targeted amount of power to be dissipated;
delivering an electrical current to at least one self-regulating thin film heating arrangement including a positive temperature coefficient (PTC) heating element having a first resistance connected in series with a negative temperature coefficient (NTC) heating element having a second resistance, a sum of the first and second resistances defining a total resistance of the self-regulating thin film heating arrangement;
outputting the targeted maximum current from the PTC heating element to the NTC heating element;
dissipating the targeted amount of power via the NTC heating element in response to flowing the targeted maximum current therethrough to generate heat; and
varying the heat emitted from the NTC heating element in response to varying a temperature surrounding the PTC heating element.

13. The method of claim 12 , further comprising varying a resistance of the PTC heating element in response to varying the temperature surrounding the PTC heating element.

14. The method of claim 13 , wherein varying the resistance includes decreasing the resistance as the surrounding temperature decreases and increasing the resistance as the surrounding temperature increases.

15. The method of claim 14 , wherein the PTC heating element outputs the current to the NTC heating element at a first current level while operating at a first surrounding temperature, and outputs the current to the NTC heating element at a second current level while operating a second surrounding temperature different than the first surrounding temperature.

16. The method of claim 15 , wherein the second current level is less than the first current level, and wherein the second temperature is greater than the first temperature.

17. The method of claim 14 , wherein the NTC heating element emits heat having a first temperature in response to receiving the current having the first current, and emits the heat having a second temperature in response to receiving the current having the second current level.

18. The method of claim 17 , wherein the second temperature is less than the first temperature.

19. The method of claim 12 , wherein the PTC heating element is a carbon black/polymer composite heater and wherein the NTC heating element is a carbon nanotube/silicone heater.

20. The method of claim 12 , wherein a tube self-regulating thin film heating arrangement is disposed in a tube assembly, wherein a strut self-regulating thin film heating arrangement is disposed in a strut assembly of the air data probe, and wherein the strut assembly is in thermal communication with the tube assembly.

Assignees

• Rosemount Aerospace Inc

Inventors

• Jacob Robin
• Mahapatra Guru Prasad

Classifications

• H05B3/46 Primary

  heating conductor mounted on insulating base · CPC title

• G01P5/165 Primary

  Arrangements or constructions of Pitot tubes · CPC title

• H05B3/58

  Heating hoses; Heating collars · CPC title

• B64D15/14

  controlled cyclically along length of surface · CPC title