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本文根据叶栅实验和流场计算结果对蒸汽轮机末级流动特征进行了分析。在小容积流量工况 ,末级流场可分为根部脱流区、脱流区之上的主流区叶栅槽道存在附体流区和分离区。三区大小随容积流量变化。由于末级流动复杂 ,发展工程上实用的算法很有吸引力。实验结果和理论分析表明 ,在小容积流量工况容易诱发叶片自激振动。为了能预估叶片颤振 ,本文发展了系列变形激盘法(机时少 ,适于工程应用 )、数值方法 (能给出叶片表面压力分布和激波振荡 ,有助于了解叶片颤振发作机理 )。经实验证明 ,可以用于叶片设计阶段颤振预估。
In this paper, the steam turbine final flow characteristics are analyzed based on the cascade experiment and flow field calculation. In the case of small volume flow, the final flow field can be divided into the root decoupling zone, and the main flow zone cascade above the decoupling zone has the appendage flow zone and separation zone. The size of the three districts with volume flow changes. Due to the complexity of the final flow, developing practical engineering algorithms is attractive. Experimental results and theoretical analysis show that the blade self-excited vibration easily induced in the small volume flow conditions. In order to predict blade flutter, this paper developed a series of deformation plate method (less timing, suitable for engineering applications), numerical methods (to give the blade surface pressure distribution and shock oscillations, to help understand the leaf flutter attack mechanism). Proved by experiments, it can be used in flutter estimation in the leaf design stage.