Thermal anti-icing system

• US 8,413,930 B2
• Filed: 03/05/2008
• Issued: 04/09/2013
• Est. Priority Date: 03/06/2007
• Status: Active Grant

• Current Assignee: GKN Aerospace Services Limited (Melrose Industries Plc)
• Original Assignee: GKN Aerospace Services Limited (Melrose Industries Plc)
• Inventors: Gregory, Karl, Sheppard, Michael James, Attrill, Scott
• Primary Examiner(s): DINH, TIEN QUANG
• Application Number:
  US12/529,633
• Publication Number:
  US 20100163678A1
• Time in Patent Office: 1,861 Days
• Field of Search: 244/134.R, 244/134.B, 60/390.93, 415/116
• US Class Current: 244/134.B
• CPC Class Codes: B64D 15/04 Hot gas application
• CPC Class Codes: B64D 2033/0233 comprising de-icing means

Abstract

An air intake duct of an aircraft engine or other component is provided with a thermal anti-icing system. The front of the air intake duct comprises a toroidal outer skin (16) which forms, with a toroidal internal bulkhead (18), a toroidal plenum (8) about the center line (26). The bulkhead has an inner edge nearest the center line. Within the plenum there is a toroidal inner skin (9) defining with the outer skin a substantially continuous toroidal channel (19). Hot air is supplied via an inlet (7) to the plenum (8). The air flows into an inlet (14) at an end of channel (19) and out of an outlet (11) through the bulkhead (18). This provide more heat to the leading edge of the duct, and to the surface of the duct facing the center line, than to other parts of the duct to prevent build up of ice which may enter, and damage, the engine. This reduces the mass flow of hot air needed for de-icing.

Claims

1. An air intake duct for use in an aircraft, the duct comprising:

a toroidal leading section having a toroidal plenum defined by an outer skin of the duct and an internal bulkhead;

an inner skin defining a toroidal air flow channel extending, within the plenum, over a portion of the outer skin thereby defining a double walled skin section of the plenum, the inner skin encompassing a zone of variation of the position of the stagnation point of the airflow over the outer skin over the flight envelope of the aircraft and the plenum having another skin section which is single walled;

an inlet for supplying hot air to the plenum;

an inlet for supplying the hot air to the channel; and

an outlet for venting air;

wherein the toroidal air flow channel forms a substantially continuous toroidal air flow space and wherein one end of the inner skin is supported by a first support and another end is supported by a second support, the inner skin being moveable relative to one of the supports.

2. The duct of claim 1, comprising a plurality of inlets distributed over, and extending through, the inner skin for supplying the hot air from the plenum to the channel.

3. The duct of claim 1, comprising a plurality of outlets, for venting air from the channel and the plenum.

4. The duct of claim 3, wherein the outlets vent air to the exterior of the duct.

5. The duct of claim 3, wherein the outlets vent air to further channels of the duct.

6. The duct of claim 1, wherein

the inner skin extends, within the plenum, over the outer skin from a toroidally inner edge of the bulkhead at one end of the channel upstream to, and past, a leading edge of the duct, and then downstream to the other end of the channel at which the channel is closed,

the inlet for supplying hot air to the plenum includes a plurality of inlets that are distributed over, and extend through, the bulkhead for supplying hot air to the plenum;

the inlet for supplying the hot air to the channel includes a plurality of inlets that are distributed over, and extend through, the inner skin for supplying hot air from the plenum to the channel adjacent the closed end of the channel; and

the outlet for venting air includes a plurality of outlets that are distributed around, and extend through, the bulkhead at the inner edge thereof.

7. The duct of claim 1, wherein the inner skin is slidably supported by one of the supports.

8. The duct of claim 1 comprising heat transfer elements attached to the outer skin within the double walled skin section, the heat transfer elements being spaced from the inner skin.

9. The duct of claim 8, wherein the heat transfer elements are fins attached to the outer skin within the double walled skin section.

10. The duct of claim 1, wherein the arrangement of the toroidal airflow channel and the inlets and outlets provides balanced airflow in the toroidal channel.

11. The duct of claim 1, further comprising spacers attached to one of the outer skin and the inner skin within the double walled skin section, the spacers comprising one or more of spaced-apart pillars, spaced-apart walls, or walls having airflow passages therethrough to allow airflow to pass around the toroidal channel.

12. An aircraft comprising an air intake duct, the air intake duct comprising:

a toroidal leading section having a toroidal plenum defined by an outer skin of the duct and an internal bulkhead;

an inner skin defining a toroidal air flow channel extending, within the plenum, over a portion of the outer skin thereby defining a double walled skin section of the plenum, the inner skin encompassing a zone of variation of the position of the stagnation point of the airflow over the outer skin over the flight envelope of the aircraft and the plenum having another skin section which is single walled;

an inlet for supplying hot air to the plenum;

an inlet for supplying the hot air to the channel; and

an outlet for venting air;

wherein the toroidal air flow channel forms a substantially continuous toroidal air flow space and wherein one end of the inner skin is supported by a first support and another end is supported by a second support, the inner skin being moveable relative to one of the supports.

13. The aircraft of claim 12, wherein the air intake duct is that of a propulsion engine of the aircraft.

14. The aircraft of claim 13, wherein the engine is a gas turbine engine.

15. The aircraft of claim 14, wherein the air intake duct is that of a cooler.

16. The aircraft of claim 12, wherein the inlet to the plenum is connected to the engine to receive hot air therefrom.

17. The aircraft as claimed in claim 12 comprising heat transfer elements attached to the outer skin within the double walled skin section, the heat transfer elements being spaced from the inner skin.

18. The aircraft of claim 12, further comprising spacers attached to one of the outer skin and the inner skin within the double walled skin section, the spacers comprising one or more of spaced-apart pillars, spaced-apart walls, or walls having airflow passages therethrough to allow airflow to pass around the toroidal channel.