Gas turbine engine outer case with contoured bleed boss

摘要

An axially extending outer case for a gas turbine engine comprises an arcuate case wall, an opening, a boss and contouring. The arcuate case wall has an inner surface and an outer surface. The opening extends through the arcuate case wall. The boss extends radially from the outer surface of arcuate case wall and surrounds the opening. The contouring surrounds the opening along the inner surface of the arcuate case wall within the boss.

主权项

1. An axially extending outer case for a gas turbine engine, the outer case comprising:
an arcuate case wall having an inner surface and an outer surface; an opening extending through the arcuate case wall; a boss extending radially from the outer surface of the arcuate case wall and surrounding the opening, wherein the boss comprises:
a flange surrounding the opening, the flange having:
an inner sidewall;an outer boss surface; andan outer sidewall; a bump-out extending circumferentially along the arcuate case wall, a portion of the bump-out forming a corner of a flow path that extends from an interior of the arcuate case to the flange, wherein the bump-out increases a local radius of the arcuate case wall as compared to a radius of the inner and outer surfaces with respect to a centerline; and contouring surrounding the opening along the inner surface of the arcuate case wall within the boss, wherein the contouring provides a smooth transition between the inner surface of the arcuate case wall and the inner sidewall; wherein:
the inner surface adjoins the bump-out at an inner edge of the corner;the inner sidewall adjoins the bump-out at an outer edge of the corner;a first projection extending from the inner edge tangent to the inner surface at the corner forms a first, obtuse, intersection angle with a second projection extending from the outer edge and parallel to the inner sidewall at the corner;a third projection extending from the inner edge tangent to the bump-out at the corner forms a second intersection angle with the second projection that is greater than the first, obtuse, intersection angle; anda region swept by the first and second intersection angles encompass the corner.