A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.

A turbine rotor blade row includes: a plurality of turbine rotor blades disposed along a circumferential direction of a hub. An inter-blade flow channel has a first cross-sectional shape perpendicular to a radial direction of the hub at a first position in the radial direction, and a second cross-sectional shape perpendicular to the radial direction of the hub at a second position farther from the hub than the first position in the radial direction. The first cross-sectional shape has a throat portion between an inlet and an outlet of the inter-blade flow channel in an axial direction of the hub. An expression A1/B1>A2/B2 is satisfied, where A1 and A2 are flow-channel widths of the first cross-sectional shape at the outlet of the inter-blade flow channel and at the throat portion, respectively, and A2 and B2 are flow-channel widths of the second cross-sectional shape at the outlet of the inter-blade flow channel and at the same position as the throat portion in the axial direction of the hub, respectively.

A gas turbine engine component includes a body defining a cooling inlet and a cooling outlet in fluid communication through a cooling channel extending through the body, and a plurality of pedestals positioned in the cooling channel. The plurality of pedestals arranged such that the adjacent pedestals alternatingly converge toward a first wall of the cooling channel and toward a second wall, opposite the first wall. A gas turbine engine includes a combustor, and a plurality of gas turbine engine components positioned in fluid communication with the combustor. Each component includes a body defining a cooling inlet and a cooling outlet in fluid communication through a cooling channel extending through the body. A plurality of pedestals are positioned in the cooling channel and are arranged such that the adjacent pedestals alternatingly converge toward a first wall of the cooling channel and toward a second wall, opposite the first wall.

A gas turbine engine comprising in flow series: a fan; a series of outlet guide vanes; and a bifurcation. The outlet guide vanes are more densely distributed in a region circumferentially aligned with the bifurcation than in a region circumferentially offset from the bifurcation.

A method of manufacturing a gas turbine engine including designing a row of vanes provided upstream of an asymmetric gas flow volume. The method includes two dimensionally optimising camberline and stagger angle of each vane, including using orthogonal polynomials to modify the camberline and stagger angle of each vane.

A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.

A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.