Turbine rotor blade row, turbine stage and axial flow turbine

摘要

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/B1A2/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.