TURBINE STATOR VANE DESIGNING METHOD, TURBINE STATOR VANE, AND STEAM TURBINE DEVICE USING TURBINE STATOR VANE

摘要

Provided is a turbine stator vane having a low aspect ratio, whereby the sidewall loss can be reduced, and the stage efficiency can be improved. The turbine stator vane, which is for an axial flow turbine, is a low-aspect-ratio stator vane, and has a s/t value (s: throat length, t: pitch length) distribution formed in an arciform manner from the root of the vane to the tip of the vane in the height direction of the vane. The s/t value is maximum between the center and the tip of the vane in the height direction of the vane, and is minimum at the root of the vane. The s/t value at the tip of the vane is determined so as to be not less than the intermediate value between the maximum s/t value and the minimum s/t value and less than the maximum s/t value, and the s/t value at the root of the vane is determined so as to be not less than 65 % of the maximum s/t value and less than the s/t value at the root of the vane when designing a free vortex.