蒸汽轮机抽汽口流场的数值模拟

用数值模拟的方法对大功率蒸汽轮机抽汽口(从通流部分到抽汽管)的流场进行了研究，给出了流场模拟的数学模型及其解法。详细描述了从通流部分到抽汽管的各段内流场的结构。指出：由于抽汽的影响，在通流部分外径处抽汽缝进口前壁的位置形成了一个惯性涡区，相对于抽汽道其它部分来说，该旋涡区所造成的流动损失最大；在通流部分不但出现了参数的径向不均匀分布，也出现了参数的周向不均匀分布；集气室内形成了一对旋转方向相反的螺旋涡，并将计算结果与实验结果进行了比较。

Numerical Simulation of the Flow Field at the Steam Extraction Opening of a Steam Turbine

By using a numerical simulation method an investigation was conducted regarding the flow field of the steam extraction opening (from a flow passage to a steam extraction pipe) of a large-sized steam turbine, leading to the setting-up of a mathematical model for flow field simulation. A method for solving the model is also provided. Furthermore, a detailed account is given of the flow field structure in various sections from the flow passage to the steam extraction pipe. It is noted that due to the influence of steam extraction an inertial vortex zone has emerged near the front wall of the steam extraction slot inlet at the flow path outside diameter location. Relative to the other portions of the steam extraction tract the flow loss caused by the vortex zone happens to be the highest. At the flow path there appears both a radial and peripheral non-uniform distribution of parameters. A pair of spiral vortex with an opposite direction of rotation was formed in a plenum. The results of calculation were compared with those of experiments.