轴流无叶喷嘴出口子午倾角对级特性的影响

THE EFFECT OF THE MERIDIANAL EXIT INCIDENCE OF AXIAL-FLOW VANELESS NOZZLES ON TURBINE PERFORMANCE

本文对3套不同出口子午倾角的轴流无叶喷嘴出口气流参数分布规律进行了比较,初步分析了这种三维边界层的结构,并据此引入了环量损失修正系数,以更准确地反映损失对气流参数的影响;通过对压力的径向平衡计算,分析了各因素对压力分布的影响,并提出用大的内环出口倾角来控制根部边界层内α_1角的过分增大。本文实验用的喷嘴型线变化范围比较广,得出的参数分布较有规律,对轴流无叶喷嘴透平的流型设计有较高的参考价值。

This paper compares the distributions of parameters in three axial-flow vaneless-nozzles which have different meridianal exit incidences and analyses the structure of 3-dimensional boundary layer. Then the correction coefficient of circulation loss is used to consider the influence of losses on the flow para- meters more accurately. The experimental results and analysis show that the large meridianal incidence at the exit of inner ring can restrict the increase of outlet flow angle. Finally, the radial distributions of parameters and radial pres- sure equilibrium are discussed.