An apparatus comprising: a bladed turbomachinery component, and a gas turbine engine flow path structure structured for use to define a flow path in a turbomachinery component (52, 56), the flow path structure having a flow surface that extends along an upstream portion and a downstream portion and where the upstream portion and the downstream portion are coincident with the bladed turbomachinery component such that the upstream portion and the downstream portion are immediately radially outside of the bladed turbomachinery component, the upstream portion having a cylindrical shape that extends aft from a first axial location to a second axial location, the downstream portion having a conical shape with linear slope extending from the second axial location to a third axial location such as to form a flat cone, the conical shape having a larger radius at the second axial location than a radius at the third axial location, wherein the flow surface includes a rounded surface that extends forward and aft of the second axial location such that the second axial location is offset from the flow surface, and wherein the third axial location is aft of the axial location at which the tip of the bladed turbomachinery component and the trailing edge of the bladed turbomachinery component meet, wherein the rounded surface includes a constant radius that blends the upstream portion with the downstream portion, wherein the second axial location is at about 1⁄4 the distance from the axial location at which the tip of the bladed turbomachinery component and the leading edge of the bladed turbomachinery component meet to the trailing edge, and wherein the first axial location is upstream of the leading edge of the bladed turbomachinery component. a bladed turbomachinery component, and a gas turbine engine flow path structure structured for use to define a flow path in a turbomachinery component (52, 56), the flow path structure having a flow surface that extends along an upstream portion and a downstream portion and where the upstream portion and the downstream portion are coincident with the bladed turbomachinery component such that the upstream portion and the downstream portion are immediately radially outside of the bladed turbomachinery component, the upstream portion having a cylindrical shape that extends aft from a first axial location to a second axial location, the downstream portion having a conical shape with linear slope extending from the second axial location to a third axial location such as to form a flat cone, the conical shape having a larger radius at the second axial location than a radius at the third axial location, wherein the flow surface includes a rounded surface that extends forward and aft of the second axial location such that the second axial location is offset from the flow surface, and wherein the third axial location is aft of the axial location at which the tip of the bladed turbomachinery component and the trailing edge of the bladed turbomachinery component meet, wherein the rounded surface includes a constant radius that blends the upstream portion with the downstream portion, wherein the second axial location is at about 1⁄4 the distance from the axial location at which the tip of the bladed turbomachinery component and the leading edge of the bladed turbomachinery component meet to the trailing edge, and wherein the first axial location is upstream of the leading edge of the bladed turbomachinery component.