Theoretical prediction of subcritical transition to turbulence using homoclinic orbits

2016 Fiscal Year Final Research Report

• Project/Area Number: 26630055
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Fluid engineering
• Research Institution: Osaka University
• Principal Investigator: Kawahara Genta 大阪大学, 基礎工学研究科, 教授 (50214672)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 乱流 / 亜臨界乱流遷移

Outline of Final Research Achievements

In pipe flow the streamwise-localized periodic edge state found by Avila et al. was reproduced by a shooting method. In plane Poiseuille flow the streamwise- and spanwise-localized periodic edge state found by Zammert and Eckhardt was recomputed by a shooting method as well as a Newton-Krylov method. We have succeeded in the theoretical description of a transition route to turbulence through the growth of a turbulent puff or a turbulent spot in terms of the unstable manifold of these spatially localized edge states. We have also discovered a periodic edge state representing a turbulent band in plane Poiseuille flow as well as a steady traveling-wave edge state corresponding to a turbulent puff or a turbulent spot in rectangular-duct flow.

Free Research Field

熱流体工学