US 11,980,972 B2
Inner barrel of an engine inlet with laser-machined acoustic perforations
Jake Adam Reeves, Newcastle, WA (US); Mark Alan Negley, Tukwila, WA (US); Eric Herrera, Mukilteo, WA (US); John Scott Bauman, Seattle, WA (US); Brandon L. Bertolucci, Seattle, WA (US); and Perry T. Horst, Tacoma, WA (US)
Filed by THE BOEING COMPANY, Chicago, IL (US)
Filed on Jun. 9, 2021, as Appl. No. 17/343,383.
Application 17/343,383 is a division of application No. 15/964,331, filed on Apr. 27, 2018, granted, now 11,052,490.
Prior Publication US 2021/0291302 A1, Sep. 23, 2021
Int. Cl. B23K 26/382 (2014.01); B23K 101/00 (2006.01); F02C 7/045 (2006.01)
CPC B23K 26/389 (2015.10) [F02C 7/045 (2013.01); B23K 2101/001 (2018.08); F05D 2220/323 (2013.01); F05D 2230/13 (2013.01); F05D 2250/18 (2013.01); F05D 2260/96 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A forming system comprising:
a femtosecond laser configured to emit laser pulses onto an inner surface of a face sheet of an acoustic inner barrel, the acoustic inner barrel including an acoustic core comprising an array of hexagonal cells attached to an outer surface of the face sheet that is opposite the inner surface; and
a control unit comprising one or more processors operatively connected to the femtosecond laser, the control unit configured to control the femtosecond laser to laser drill a plurality of perforations in the face sheet via emitting laser pulses at pulse durations between about 100 femtoseconds and about 10,000 femtoseconds and at frequencies over 100,000 Hz,
wherein the control unit is configured to control the femtosecond laser to emit the laser pulses at multiple perforation locations along the face sheet one at a time in a sequence such that a first set of one or more laser pulses is emitted at a first perforation location and then a second set of one or more laser pulses is emitted at a second perforation location, the control unit further configured to control the femtosecond laser to repeat the sequence multiple times to gradually form the perforations at the multiple perforation locations, and
wherein the control unit is further configured to control the femtosecond laser to repeat the sequence such that a third set of one or more laser pulses is emitted at the first perforation location subsequent to the second set being emitted at the second perforation location and before a fourth set of one or more laser pulses is emitted at the second perforation location.