Abstract: An axial flow turbine includes in axial flow series a low pressure turbine section and a turbine exhaust system. The low pressure turbine section includes a final low pressure turbine stage having a circumferential row of static aerofoil blades followed in axial succession by a circumferential row of rotating aerofoil blades. Each aerofoil blade has a radially inner hub region and a radially outer tip region. The K value, being equal to the ratio of the throat dimension (t) to the pitch dimension (p), of each static aerofoil blade of the final low pressure turbine stage varies along the height of the static aerofoil blade, between the hub region and the tip region, according to a substantially W-shaped distribution.

Abstract: An axial flow turbine includes in axial flow series a low pressure turbine section and a turbine exhaust system. The low pressure turbine section includes a final low pressure turbine stage having a circumferential row of static aerofoil blades followed in axial succession by a circumferential row of rotating aerofoil blades. Each aerofoil blade has a radially inner hub region and a radially outer tip region. The K value, being equal to the ratio of the throat dimension (t) to the pitch dimension (p), of each static aerofoil blade of the final low pressure turbine stage varies along the height of the static aerofoil blade, between the hub region and the tip region, according to a substantially W-shaped distribution.