The flow line function and the flow function for extrusion were obtained from the construction of velocitydiscontinuity 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。
2
At the striking position of the high-speed fluid to the static fluid, a velocitydiscontinuity appears, which propogates outwards in the film.
在高速流动的流体和静止流体撞击位置，流动速度出现间断，该速度间断的位置不断向液滴冲击区域外扩展。
3
Using the shearing rate of work on then surfaces of velocitydiscontinuity and the tensional rate of work are taken into account when computing the total functional.