Abstract:
A fan case assembly includes a noise attenuation layer that is covered by a face sheet. The face sheet includes a first plurality of openings. The noise attenuation layer includes a plurality of individual cells that are in communication with at least one of the first plurality of openings. Noise energy is communicated through the first plurality of openings into the individual cells and dissipated to reduce noise emissions. A seam in the face sheet is covered to protect the underlying noise attenuation layer from damage by a retainer. The retainer i s bonded to the face sheet over the seam and includes a second plurality of holes that communicates noise energy through the retainer to the noise attenuation laye r. Communication of noise energy through the retainer provides an acoustically active seam that aids in the dissipation of noise energy and thereby reduces the level of sound emitted from the engine.
Abstract:
A drain assembly 30 for a case 26 is disclosed. Various construction details are developed for minimizing the radial profile and facilitating assembly to an opening in the case while blocking the passage of flames from the exterior to the interior. In one embodiment, the drain assembly 30 has a cover 42 facing one side of the case with passages 48 therethrough, a plate 58 having a passage 62 on the other side of the case, and a baffle 66 disposed in the opening to block flames from passing between the cover side of the case and the plate side of the case.
Abstract:
A penetration resistant turbine engine fan casing (12) for containing separated fragments of a fan blade (16) includes a penetration susceptible support case (14), a penetrable covering (32) circumscribing an impact zone (I) of the support case and an optional collapsible support covering (34) circumscribing the case but axially offset from the impact zone. A containment covering (36) circumscribes both the penetrable covering (32) and the support covering (34). In a preferred embodiment, the coverings are aromatic polyamide fiber fabrics and the support covering is a collapsible cellular array. In operation, a detached fragment of a fan blade penetrates through the case (14) and the penetrable covering (32), and is plastically deformed by the penetrable covering to reduce the fragment's potential for damaging the containment covering (36). The containment covering intercepts the deformed fragment, confining it to a predetermined radial envelope bounded by the inner surface (58) of a nacelle (52). The impact forces arising from a separated blade fragment cause the containment fabric to collapse the cellular array (32) and momentarily detension the containment fabric to maximize its penetration resistance.
Abstract:
A liner assembly for a fan case includes a noise attenuation layer covered by a face sheet. The face sheet includes openings to the underlying noise attenuation layer. The face sheet and noise attenuation layer include acoustically transparent joints. The noise attenuation layer includes a first side joined to a second side at a seam by an adhesive strip. The adhesive strip bonds the first side to the second side without filling any chambers. The face sheet includes a joint filled with an adhesive providing the desired uninterrupted surface within the fan case. Openings ar e formed through the joint and the adhesive to communicate with the underlying noise attenuation layer. The joint and seam become essentially transparent acoustically to improve noise attenuation performance.
Abstract:
A drain assembly 30 for a case 26 is disclosed. Various construction details are developed for minimizing the radial profile and facilitating assembly to an opening in the case while blocking the passage of flames from the exterior to the interior. In one embodiment, the drain assembly 30 has a cover 42 facing one side of the case with passages 48 therethrough, a plate 58 having a passage 62 on the other side of the case, and a baffle 66 disposed in the opening to block flames from passing between the cover side of the case and the plate side of the case.
Abstract:
A drain assembly 30 for a case 26 is disclosed. Various construction details are developed for minimizing the radial profile and facilitating assembly to an opening in the case while blocking the passage of flames from the exterior to the interior. In one embodiment, the drain assembly 30 has a cover 42 facing one side of the case with passages 48 therethrough, a plate 58 having a passage 62 on the other side of the case, and a baffle 66 disposed in the opening to block flames from passing between the cover side of the case and the plate side of the case.
Abstract:
A blade containment system includes a plurality of circumferentially-arranged rotatable blades. Each blade has a blade compliance. An annular containment structure is arranged around the rotatable blades. The containment structure includes a liner that has a liner compliance. The blade compliance and the liner compliance are configured such that a strain induced on a respective one of the blades upon impact with the liner is less than a threshold critical strain beyond which the rotatable blades fracture.