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EP-4737699-A1 - ACOUSTIC STRUCTURE WITH ARRAY OF INTERCONNECTED RESONATORS, AND ANTI-ICING SYSTEM

EP4737699A1EP 4737699 A1EP4737699 A1EP 4737699A1EP-4737699-A1

Abstract

A gas turbine engine (20) includes a fan (42) delivering air into a bypass duct (13) defined between a nacelle (301) and an inner core housing (15). The inner core housing (15) receives a compressor section (24), a turbine section (28) and a combustor (56). The nacelle (301) has an inner periphery (141) with a forwardmost point, and receives an acoustic structure on the inner periphery (141) adjacent the forwardmost point. The acoustic structure is defined by a three dimensional array (100) of interconnected resonators (102), with the interconnected resonators (102) extending in a radial direction (R), a circumferential direction (C) and an axial direction (A) all defined about a rotational axis (A) of the engine (20), with the interconnected resonators (102) having a larger cross-sectional area central body (104), and six members (106, 108, 110, 112, 143; 198) connecting the central body (104) of the resonators (102) to adjacent resonators (102) at respective central bodies (104). A perforated face sheet (118) is inward of the three dimensional array (100) of interconnected resonators and an anti-icing system.

Inventors

  • WINKLER, JULIAN
  • REIMANN, CRAIG A.
  • HOMMA, KENJI
  • MENDOZA, Jeffrey M.
  • GOK, GURKAN
  • MANTESE, JOSEPH V.

Assignees

  • RTX Corporation

Dates

Publication Date
20260506
Application Date
20251031

Claims (15)

  1. A gas turbine engine (20) comprising: a fan (42) delivering air into a bypass duct (13) defined between a nacelle (301) and an inner core housing (15), said inner core housing (15) receiving a compressor section (24), a turbine section (28) and a combustor (56), said nacelle (301) having an inner periphery (141) with a forwardmost point; an acoustic structure on the inner periphery (141) of the nacelle (301) adjacent the forwardmost point, the acoustic structure being defined by a three dimensional array (100) of interconnected resonators (102), with the interconnected resonators (102) extending in a radial direction, a circumferential direction and an axial direction all defined about a rotational axis (A) of the engine (20), with the interconnected resonators (102) having a central body (104), and six tubes (106, 108, 110, 112, 143; 198) connecting the central body (104) of the resonators (102) to adjacent resonators (102) at respective central bodies (104), wherein the central body (104) has a larger cross-sectional area than the tubes (106...198); a perforated face sheet (118) radially inward of the three dimensional array (100) of interconnected resonators (102); and an anti-icing system.
  2. The gas turbine engine (20) as set forth in claim 1, wherein there is an opening (114) through the central body (104) and at least some of the tubes (110, 112) adjacent central body (104), and there being openings (114) formed between adjacent ones of the resonators (102) and extending in the circumferential, radial and axial directions.
  3. The gas turbine engine (20) as set forth in claim 2, wherein the anti-icing system is configured to provide heated fluid (301) to melt ice at the inner periphery (141) of the nacelle (301).
  4. The gas turbine engine (20) as set forth in claim 3, wherein a space (116) between adjacent ones of the resonators (102) is configured to receive the heated fluid (301) and the openings (114) in the tubes (108) are blocked from the heated fluid (301) to provide the acoustic structure, and optionally wherein interconnected resonators (102) are configured such that the heated fluid (301) flowing through the space (116) does not communicate with adjacent resonators (102) in a radial dimension but is blocked.
  5. The gas turbine engine (20) as set forth in claim 1 or 2, wherein the anti-icing system includes an electric heater (144) positioned between the three dimensional array (100) of interconnected resonators (102) and the perforated face sheet (118).
  6. The gas turbine engine (20) as set forth in claim 5, wherein the electric heater (144) comprises a heated wire mesh (144) and a control (146) supplying electric power to the heated wire mesh (144) such that there are openings within the electric heater (144), or wherein the electric heater (144) is provided by a heated wire pattern (152) with openings between portions of the pattern (152) to allow acoustic waves to access the three dimensional array (100), and optionally wherein the heated wire pattern (152) is provided by carbon nanotube heaters.
  7. The gas turbine engine (20) as set forth in claim 1 or 2, wherein the anti-icing system is provided by radio frequency waves.
  8. The gas turbine engine (20) as set forth in claim 7, wherein a radio frequency absorber (162) is positioned between the three dimensional array (100) and the perforated face sheet (118), and there is a radio frequency radiator (164), and the three dimensional array (100) is more transparent to radio frequency waves than is the radio frequency absorber (162).
  9. The gas turbine engine (20) as set forth in claim 8, wherein the radio frequency absorber (162) is provided by the three dimensional array (100), and/or wherein the radio frequency absorber (162) is capable to convert more than 50% of received radio frequency energy into heat across a range of 1-100 Gigahertz.
  10. The gas turbine engine (20) as set forth in claim 8 or 9, wherein a control (166) for the radio frequency radiator (164) is configured to initially provide waves at a frequency tuned for absorption by the radio frequency absorber (162), and at a later point switche the frequency to one at which the radio frequency absorber (162) is more transparent, to channel the radio frequency power radially inward of the acoustic structure.
  11. The gas turbine engine (20) as set forth in any preceding claim, wherein there is a partition (172; 197) between subportions (102A, 102B; 192, 194, 196) of the three dimensional array (100).
  12. The gas turbine engine (20) as set forth in claim 11, wherein there are plurality of partitions (172; 182; 184; 197).
  13. The gas turbine engine (20) as set forth in claim 12, wherein the partitions (172; 197) are solid and configured to isolate the subportions (102A...196), or wherein the partitions (182; 184) are perforated such that there is acoustic communication between adjacent ones of the subportions (102A, 102B).
  14. The gas turbine engine (20) as set forth in claim 11, 12 or 13, wherein there are spaced subportions (192, 194, 196) of the three dimensional array (100) which are interconnected by a tube (198) that is open at least one end.
  15. The gas turbine engine (20) as set forth in any preceding claim, wherein the resonators (102) have a curved bulb like structure.

Description

TECHNICAL FIELD This application relates to an acoustic structure formed of a three dimensional array of interconnected resonators, and an anti-icing system. BACKGROUND Gas turbine engines are known, and typically include a propulsor delivering air into a nacelle as bypass air, and into a core engine. In the core engine, a compressor compresses air and delivers compressed air into a combustor where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors, driving them to rotate. The turbine rotors in turn drive the compressor and fan rotor. There are challenges with gas turbine engines. One challenge is the suppression of sound adjacent a forward end of the nacelle. Acoustic treatments are typically provided at that location. One recently developed acoustic treatment is provided by a three dimensional array of interconnected resonators. Another challenge with gas turbine engines is to deice the forwardmost end of the inner periphery of the nacelle. In some ways, providing acoustic treatment complicates providing anti-icing. SUMMARY In an aspect of the present invention, a gas turbine engine includes a fan delivering air into a bypass duct defined between a nacelle and an inner core housing. The inner core housing receives a compressor section, a turbine section and a combustor. The nacelle has an inner periphery with a forwardmost point, and receives an acoustic structure on the inner periphery adjacent the forwardmost point. The acoustic structure is defined by a three dimensional array of interconnected resonators, with the interconnected resonators extending in a radial direction, a circumferential direction and an axial direction all defined about a rotational axis of the engine, with the interconnected resonators having a larger cross-sectional area central body, and six members connecting the central body of the resonators to adjacent resonators at respective central bodies. A perforated face sheet is inward of the three dimensional array of interconnected resonators and an anti-icing system. In an embodiment of the above, there is an opening through the central body and at least some of the tube portions adjacent central body. There are openings formed between adjacent ones of the cells and extending in the circumferential, radial and axial directions. In another embodiment according to any of the previous embodiments, the anti-icing system provides heated fluid to melt ice at the inner peripheral of the nacelle. In another embodiment according to any of the previous embodiments, an enlarged area opening between adjacent ones of the resonators provides a flow path for heated fluid (i.e., receives the heated fluid) and the openings in the tubes are blocked from the heated fluid to provide the acoustic structure. In another embodiment according to any of the previous embodiments, the heated fluid flowing through the enlarged space does not communicate with adjacent cells in a radial dimension but is blocked. In another embodiment according to any of the previous embodiments, the anti-icing system includes an electric heater positioned between the three dimensional array of interconnected resonators and the perforated face sheet. In another embodiment according to any of the previous embodiments, the electric heater has a control supplying electric power to a heated wire mesh such that there are openings within the electric heater. In another embodiment according to any of the previous embodiments, the electric heater is provided by a pattern with openings between portions of the pattern to allow acoustic waves to access the three dimensional array. In another embodiment according to any of the previous embodiments, the heated wire pattern is provided by carbon nanotube heaters. In another embodiment according to any of the previous embodiments, the anti-icing system is provided by radio frequency waves, or the anti-icing system comprises a radio frequency emitter. In another embodiment according to any of the previous embodiments, a radio frequency absorber is positioned between the three dimensional array and the perforated face sheet. There is a radio frequency radiator, and the three dimensional array is more transparent to radio frequency waves than is the radio frequency absorber. In another embodiment according to any of the previous embodiments, the radio frequency absorber is provided by the three dimensional array. In another embodiment according to any of the previous embodiments, the radio frequency absorber is capable to convert more than 50% of received radio frequency energy into heat across a range of 1-100 Gigahertz. In another embodiment according to any of the previous embodiments, a control for the radio frequency radiator initially provides waves at a frequency tuned for absorption by the radio frequency absorber, and at a later point switches the frequency to one at which the radio frequency absorber is more transparent, to channel the radi