| 摘要 |
An axial flow gas turbine comprises a turbine and a turbine exhaust section. The turbine comprises a turbine nozzle containing a low pressure turbine stage having an annular row of stator vanes (V2) followed in axial succession by an annular row of rotor blades (B2). The low pressure turbine stage is characterized by the following parameters: the ratio of vane airfoil pitch to vane airfoil axial width (P/W) at the root end of the vane airfoil (V2) is in the region of 1.0 to 1.2, preferably about 1.12; the ratio of blade airfoil pitch to blade airfoil axial width (P/W)at the root end of the blade airfoil (B2) is in the region of 0.6; the ratio of blade diameter at the tip end of the blade airfoil to blade diameter at the root end of the blade airfoil (blade tip/hub diameter ratio) is in the region of 1.6-1.8, preferably about 1.72; and the ratio of the axial length of the exhaust section to the blade airfoil height (L/H) is no greater than a value in the region of 4:1, preferably 3:1. These parameters are subject to a permitted variation of up to ±10%, preferably up to ±5%. Dimensions of example airfoils are given and are scaleable to produce turbines of any chosen power.
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