Abstract: A turbine blade includes a labyrinth of internal channels for the circulation of coolant received through an inlet formed in a terminal portion of the blade root and leading to a duct-defined wall. A first passage intersects the duct and extends through the blade towards a tip. An end of the first passage is arranged to capture incoming coolant flow. A second passage intersects the duct at a position downstream of the first passage intersection. The duct and/or the passage intersections are configured to create a pressure drop in the duct in the direction from the inlet to the second passage intersection. In an axial direction, a duct wall terminates at a position between the inlet and the second passage intersection.

Abstract: A turbine stage assembly includes a disc carrying a cascade of blades and an annular seal-plate that is secured to the disc by a first connection. One or more of the blades include a root portion configured to be received in a complementarily shaped radially extending slot in the disc such that a face of the root portion faces the plate. A terminal portion of the root portion is cut away adjacent the face to present an open space between a radially inner wall of the slot and a wall of the cutaway root portion. A first part of a second connector extends radially inwardly from the wall of the cutaway root portion. The first part of the second connector is configured to engage with a complementing second part of the second connector provided on the seal-plate.

Abstract: A turbine blade includes a labyrinth of internal channels for the circulation of coolant received through an inlet formed in a terminal portion of the blade root and leading to a duct- defined wall. A first passage intersects the duct and extends through the blade towards a tip. An end of the first passage is arranged to capture incoming coolant flow. A second passage intersects the duct at a position downstream of the first passage intersection. The duct and/or the passage intersections are configured to create a pressure drop in the duct in the direction from the inlet to the second passage intersection. In an axial direction, a duct wall terminates at a position between the inlet and the second passage intersection to balance the pressure of coolant in the duct with the pressure of coolant in a leakage path thereby reducing the mass flow of coolant entering the leakage path.

Abstract: A turbine blade includes a labyrinth of internal channels for the circulation of coolant received through an inlet formed in a terminal portion of the blade root and leading to a duct- defined wall. A first passage intersects the duct and extends through the blade towards a tip. An end of the first passage is arranged to capture incoming coolant flow. A second passage intersects the duct at a position downstream of the first passage intersection. The duct and/or the passage intersections are configured to create a pressure drop in the duct in the direction from the inlet to the second passage intersection. In an axial direction, a duct wall terminates at a position between the inlet and the second passage intersection to balance the pressure of coolant in the duct with the pressure of coolant in a leakage path thereby reducing the mass flow of coolant entering the leakage path.

Abstract: A turbine stage assembly includes a disc carrying a cascade of blades and an annular seal-plate that is secured to the disc by a first connection. One or more of the blades include a root portion configured to be received in a complementarily shaped radially extending slot in the disc such that a face of the root portion faces the plate. A terminal portion of the root portion is cut away adjacent the face to present an open space between a radially inner wall of the slot and a wall of the cutaway root portion. A first part of a second connector extends radially inwardly from the wall of the cutaway root portion. The first part of the second connector is configured to engage with a complementing second part of the second connector provided on the seal-plate.