蒸気タービン部分流入段の流速分布と段落効率に関する研究 Studies on Fluid Velocity Distribution and Stage Efficiency for a Partial Admission Stage of Steam Turbines

In the present paper, a 3-dimensional numerical study of partial admission stages of a steam turbine is described. Three models : Q3-D model only on mean diameter, 3-D model without tip clearances and disk cavities, and 3-D model with tip clearances and disk cavities, are applied and their results are compared with experimental results of a single stage air turbine. The mechanism of loss generation in partial admission stages is discussed by comparison with full arc admission stages. Tip leakage flow plays more significant role in partial admission stages.