平面ポァズイユ流のバイパス遷移(<小特集>流れの不安定性・乱流遷移とその応用)

概要

論文の詳細を見る
By-pass transitions of the plane Poiseuille flow originated from the various initial disturbance are simulated directly on a parallel computer. The simulations are started with initial flows given by the basic flow plus small disturbances with different amplitudes for various Reynolds numbers. It is found from the simulations that when an amplitude of the disturbance velocity is greater than the threshold value, which depends on -1.7 power of the Reynolds number, the by-pass transition of the flow is triggered by the instability of streamwisevortex components in the disturbance. From the visualization of the vortical structures in the transitional flow, we obtain that fine streamwise vortices are excited in the flow at early linear instability period and then, they are amplified to turbulent spots at nonlinear instability period. Finally, the flow breaks down to turbulence.
社団法人日本機械学会の論文
2002-04-25