평행 Poiseuille, 평행 Couette, Blasius Flow의 준안정 해석

Abstract

We investigate the spectra and the pseudospectra in plane Poiseuille flow, plane Couette flow and Blasius flow. At subcritical Reynolds number, the spectra arc lied strictly inside the stable complex half-plane, but the pseudospectra are lied in the unstable half-plane, reflecting the large linear transient growth that certain perturbations may excite. It means that the smooth flows may become to turbulent even though all the eigenmodes decay monotonicalh We found that pseudospectra is one reason that causes subcrilical transition in plane Poiseuille flow and plane Couette flow and bypass transition in Blasius flow.<br/>