The present work is carried out by direct numerical simulation ( dns ) , the non - linear navier - stokes equation is formulated in terms of spectral method with fringe method . the objective of present work is to explore the spatial and temporal evolution of pipe flow with the disturbance imposed on the pipe wall in the form of periodic suction and blowing ( psb ) 本文使用直接数值模拟（ dns ）方法，通过谱方法结合嵌边法求解非线性的navier - stokes方程，来研究由圆管壁面引入的周期性吹吸（ psb ）扰动作用下，圆管流动沿流向的空间演化规律及其相应的时间演化过程。
Based on these parameters , the present work studies the transition of pipe flow with the different amplitude of psb disturbance . the present work simulates the whole time - space process of the transition from laminar to turbulence and secondary transition phenomenon in pipe flow for the first time . the main structure in pipe flow transition is hair - pin vortex ; the evolution of hair - pin vortex is related with the transition of pipe flow 在这一组参数下，本文研究了不同扰动幅值的psb扰动作用下圆管流动的转捩过程，首次给出圆管流动从层流转捩到湍流的时空演化全过程，发现了圆管流动的二次转捩现象，并进一步揭示了发卡涡是圆管流动转捩中的主要结构，流动的转捩过程与发卡涡的演化直接相关。
