英语语法分析

The examples presented clearly show the effect of nonparallel flow on boundary layer stability.

通过算例，清楚地显示了流动的非平行性对边界层稳定性的影响。

Gears on nonparallel, non-intersecting shafts also have pitch circles, but the rolling-pitch-circle concept is not valid.

非平行的齿轮，非交叉传动的轴也有节点，但不存在纯滚动节圆的概念。

The weak nonlinear instability of a nonparallel boundary layer is studied by nonlinear parabolized stability equations(PSE).

采用非线性抛物化稳定性方程（PSE）研究了非平行边界层的弱非线性稳定性。