ACOUSTIC ATTENUATION STRUCTURES

Acoustic structures (122; 222; 322) for a gas turbine engine (100) are disclosed. In various embodiments, the acoustic structures (122; 222; 322) comprise a panel (118; 218) in the form of a cellular structure (126; 226; 326) having a plurality of cells (128; 228; 328); and a housing (240) configured to house the cellular structure (126; 226; 326), the housing (240) including a first rail (242) configured for attachment to a static structure within the gas turbine engine (100) and a second rail (244) configured for attachment to the static structure. In various embodiments, the acoustic structures (122; 222; 322) comprise a liner (116; 316) in the form of a non-segmented or two-piece structure configured to extend about the inner barrel of a nacelle structure (110). The disclosed panels and liners are configured to maximize the operational area of the acoustic structures (122; 222; 322) by eliminating obstructions from adjacent flow paths.