Swirl-enhanced aerodynamic fastener shield for turbomachine

A fastener shield for use in a fluid flow path within a gas turbine engine for reducing fluid drag and heating generated by fluid flow over a plurality of circumferentially spaced bolts, the bolts having a portion thereof extending into the fluid flow path, the fastener shield comprising:

• (a) a radially-extending, downstream-facing mounting flange having a plurality of circumferentially spaced bolt holes positioned to receive respective engine mounting bolts therethrough and to attach the mounting flange to elements of the turbine engine;
• (b) a curved, upstream-facing fastener shield cover integrally-formed with and positioned in spaced-apart relation to the mounting flange for at least partially covering and separating an exposed, upstream-facing portion of the bolts from the fluid flow to thereby reduce drag and consequent heating of the bolts, the curved shield cover comprising a bellmouth shape characterized by a progressive curve that simultaneously extends axially upstream against the direction of fluid flow and radially outwardly to a terminus positioned in a plane defined by an extended longitudinal axis of the bolt;
• and
• (c) a plurality of closely spaced-apart, spirally-oriented channels defined in the fastener shield cover for deflecting the fluid flow impinging on the fastener shield cover, thereby increasing the tangential velocity and lowering the relative temperature of the fluid flow.

A fastener shield for use in a fluid flow path within a gas turbine engine for reducing fluid drag and heating generated by fluid flow over a plurality of circumferentially spaced bolts, the bolts having a portion thereof extending into the fluid flow path, the fastener shield comprising a plurality of arcuate elements joined to collectively define:

• (a) an annular, radially-extending, downstream-facing mounting flange having a plurality of circumferentially spaced bolt holes positioned to receive respective engine mounting bolts therethrough and to attach the mounting flange to elements of the turbine engine;
• and
• (b) a curved, upstream-facing fastener shield cover positioned in spaced-apart relation to the mounting flange for at least partially covering and separating an exposed, upstream-facing portion of the bolts from the fluid flow to thereby reduce drag and consequent heating of the bolts, the curved shield cover comprising a bellmouth shape characterized by a progressive curve that simultaneously extends axially upstream against the direction of fluid flow and radially outwardly to a terminus positioned in a plane defined by an extended longitudinal axis of the bolt;
• and
• (c) a plurality of closely spaced-apart, spirally-oriented channels defined in the fastener shield cover for deflecting the fluid flow impinging on the fastener shield cover, thereby increasing the tangential velocity and lowering the relative temperature of the fluid flow.