Patent ID: 8192154

Claim:
A shape of a gas passage in an axial-flow gas turbine engine in which a plurality of inlet guide vanes (V) are radially disposed in an annular gas passage defined between an inner peripheral wall (Ch) and an outer peripheral wall (Ct), comprising: said inner peripheral wall (Ch) between a leading edge (LE) and a trailing edge (TE) of the inlet guide vane (V) comprises: an inner peripheral concave portion (Cc 1 ) curved into a concave shape in a radial direction on an upstream side of a fluid flow direction; and an inner peripheral convex portion (Cv 1 ) curved into a convex shape in the radial direction on a downstream side of the fluid flow direction; and said inner peripheral convex portion (Cv 1 ) is positioned on the outer side in the radial direction with respect to a reference line connecting inner ends in the radial direction of the leading edge (LE) and the trailing edge (TE) of the inlet guide vane (V); wherein each of said plurality of inlet guide vanes (V) includes a chord length in an axial direction that is larger relative to a span length in the radial direction with the leading edge being inclined to the upstream side at a tip side, outer side in the radial direction, as compared to the hub side, inner side in the radial direction.