Genta Kawahara

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Several aspects of the self-sustaining mechanism of near-wall turbulence have been studied recently (see Jiménez & Moin 1991; Hamilton, Kim & Waleffe 1995; Waleffe 1997; Schoppa & Hussain 1997; Jiménez & Pinelli 1998). It is well-known that there are two key structures, streamwise vortices and streaks, in the near-wall region. Streamwise vortices generate(More)
Experiments and simulations lend mounting evidence for the edge state hypothesis on subcritical transition to turbulence, which asserts that simple states of fluid motion mediate between laminar and turbulent shear flow as their stable manifolds separate the two in state space. In this Letter we describe flows homoclinic to a time-periodic edge state that(More)
Recently found unstable time-periodic solutions to the incompressible Navier-Stokes equation are reviewed to discuss their relevance to plane Couette turbulence and isotropic turbulence. It is shown that the periodic motion embedded in the Couette turbulence exhibits a regeneration cycle of near-wall coherent structures, which consists of formation and(More)
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