ACOUSTIC REFLECTOR ATTACHMENT COMPATIBLE WITH NATIVE AIRCRAFT STRUCTURE

• US 20020005070A1
• Filed: 04/23/1999
• Published: 01/17/2002
• Est. Priority Date: 04/23/1999
• Status: Active Grant

• Current Assignee: Rosemount Aerospace, Inc. (Rtx Corporation)
• Original Assignee: Rosemount Aerospace, Inc. (Rtx Corporation)
• Inventors: HONGERHOLT, DERRICK D., MATUSESKI, TIMOTHY J., RAJANA, KRISHNA M.
• Granted Patent: US 6,378,377 B2
• Time in Patent Office: Days
• US Class Current: 73/597
• CPC Class Codes: B64D 15/20 Means for detecting icing or initiating de-icing
• CPC Class Codes: G01N 2291/023 Solids
• CPC Class Codes: G01N 2291/0251 Solidification, icing, curing composites, polymerisation
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves

Abstract

An ultrasonic ice detector that can be mounted directly to the skin of an aircraft includes a transducer that is coupled to the interior surface of the skin, and transmits acoustic vibrational energy through the skin. A reflector bar having a reflector surface is mounted on the interior surface of the skin at a location spaced from the transducer and is effective to reflect acoustic energy back to the transducer. The reflector bar is raised from the interior surface and preferably has a width equal to the width of the acoustic wave that is generated by the transducer at the reflector location. The transducer and reflector are non-intrusive and do not alter the aircraft skin structural integrity. The arrangement provides an accurate, responsive sensor for determining presence of ice or other contaminants on the exterior surface of the skin.

Claims

1. A contaminant detection sensor for a wall with an exterior surface and an interior surface, the exterior surface being subjected to airflow in use, the detection sensor comprising a transmitter and receiver coupled to the interior surface of the wall at a first location and providing an acoustic energy pulse forming an acoustic wave transmitted along the wall, and a reflector discontinuity comprising a vibration reflector on the interior surface of the wall at a position spaced from the transmitter and operable to reflect acoustic waves transmitted from the transmitter assembly back to the receiver.

2. The sensor of claim 1, wherein the receiver receives a reflected acoustic wave and provides an output that is a function of the state of the exterior surface.

3. The sensor of claim 1, wherein the reflector is raised from the interior surface and has a curved surface extending outwardly from the interior surface and facing the transmitter and receiver.

4. The sensor of claim 3, wherein said curved surface has a radius substantially equal to the distance from the transmitter to the curved surface.

5. The sensor of claim 1, wherein said reflector discontinuity is constructed of the same material as the wall.

6. The sensor of claim 1, wherein the reflector comprises a bar attached to the interior surface and having a width measured perpendicular to a center line between the transmitter and the reflector bar, the width being substantially equal to the width of the transmitted acoustic wave at the location of the reflector bar.

7. The sensor of claim 1, wherein said wall comprises a curved edge portion of an air foil shape, and the transmitter and reflector discontinuity are spaced apart along a concave portion of the wall.

8. The sensor of claim 1, wherein said reflector discontinuity comprises a bar which is coupled to the interior surface with a high temperature and high strength adhesive.

9. The sensor of claim 1, wherein a surface of a reflector engaging the interior surface of the wall is conformed to the shape of the interior surface of the wall, and wherein the interior surface has a non planar cross section.

10. A contaminant detection system for a structure having a wall with an exterior surface and an interior surface, the exterior surface being subjected to airflow and subject to having contaminates such as ice deposited thereon, the detection system comprising a transmitter and receiver coupled to the interior surface of the wall at first locations and providing acoustic energy to cause vibrations in the walls propagated along a vibration wave path, and a reflector discontinuity on the interior surface of the wall at a position spaced from the transmitter and receiver and in the vibration wave path to reflect acoustic energy back to the receiver.

11. The sensor of claim 10 wherein the transmitter provides acoustic energy and the receiver receives reflected acoustic energy and provides an output that is a function of the reflected acoustic energy.

12. The sensor of claim 10 wherein the reflector is raised from the interior surface and has a curved surface extending outwardly from the interior surface and facing the transducer.

13. The sensor of claim 12, wherein the reflector comprises a bar attached to the interior surface and having a width measured perpendicular to a center line between the transmitter and the reflector bar, the width being substantially equal to the width of the vibration wave path at the location of the reflector bar.

14. A method of sensing contaminants adhering to an exterior surface of the wall of a structure over which air flows, such as a component of an airborne vehicle, comprising mounting an acoustic transducer on an interior surface of the wall, mounting a reflector on the interior surface of the aircraft skin at a location spaced from the transducer, transmitting vibrational energy along the interior surface in a path toward the reflector, and sensing vibrational energy reflected from the reflector.

15. The method of claim 14 including sensing the reflected energy at the transducer.

16. The method of claim 15 including forming a surface of the reflector to focus reflected vibration at the transducer.

17. The method of claim 14, wherein the wall is the skin of an aircraft.

18. An apparatus for detecting the presence of contaminants along an exterior surface of a curved leading edge of an aircraft wing, the wing having an interior surface opposed to the exterior surface, comprising a transducer acoustically coupled to the wing interior surface at a location downstream of the wing leading edge, and including means for sending an acoustic wave along a wave path that extends in a direction upstream from said transducer, and around the curved leading edge, a reflector acoustically coupled to the wing interior surface, said reflector having a reflecting surface that extends outwardly from the interior surface of the aircraft wing.

19. The apparatus of claim 18, wherein the reflector is of the same material as the aircraft wing.

20. The apparatus of claim 18, wherein said reflector wall extending above the interior surface is nonplanar in directions transverse to the wave path.

21. The reflector of claim 18, wherein the wave path is free of structural members that reflect acoustic energy.