The flow line function and the flow function for extrusion were obtained from the construction of velocity discontinuity lines(VDL).
由构造速度间断线模型入手，建立正挤压的流线方程，以便求得是流函数。
The discontinuity of a tuning post in fin line is firstly analyzed with mode matching method and perturbation technique.
首次应用模式匹配法和微扰法对鳍线侧边调谐螺杆不连续性进行了分析，并进行了实验研究。
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