Abstract: A thrust augmentor heat shield for enclosing radially extending fuel pipes which can be attached to and removed from the outer duct wall from within the augmentor. The heat shield includes a hollow, elongate housing extending substantially entirely along the length of the fuel pipe, a nose projecting forwardly from the housing and received within a slot formed in the duct wall and a bolt for clamping the housing to the duct wall and urging the nose of the housing into the slot. The housing includes an opening between the outer duct wall and the diffuser wall for conveying cooling air radially inwardly along the housing, and openings along lateral sides of the housing in registry with the fuel discharge ports of the fuel tube. The housing includes a diffuser flowpath segment such that, when the housings are arranged in a spoke pattern, the segments form a continuous annular wall joined by splined connections.

Abstract: A system is provided inside a turbomachine for controlling operational clearance between a turbine rotor and a surrounding turbine shroud. The system comprises a plurality of control rings, integrated into the turbine casing, that are thermally expanded and contracted to control radial positioning of the turbine shroud. Compressor air is directed through internal passages in the rings to cause the expansion and contraction. The system utilizes the pressure and temperature of compressor air, in combination with size, location, and structure of the control rings to match thermal growth of the control rings and turbine shroud to thermal growth of the turbine rotors, thereby controlling clearance.

Abstract: An apparatus is provided in a gas turbine engine for eliminating air leakage-induced vibration at natural frequencies in a type of flexible annular seal structure sometimes referred to as a floating fishmouth seal. A floating fishmouth seal has male and female sections arranged to permit axial and radial movement and still maintain a sealing relationship. In a preferred form, the apparatus for eliminating air leakage-induced vibration includes two structures that interact with the male and female sections of the fishmouth seal during engine operation. The first structure is an annular leaf spring assembly that presses a radial flange of the male section of the seal against a stationary wall to obtain frictional damping. The second structure is an annular member attached to an outer surface of the female section of the seal forming a closed-in structure to provide stability and damping. The combined effect of the two structures is to increase the operational life of the fishmouth seal.