Propagation mechanism of localized wave packet in plane-Poiseuille flow

Abstract

The convection velocity of localized wave packet in plane-Poiseuille flow is found to be determined by a solitary wave at the centerline of a downstream vortex dipole in its mean field after deducting the basic flow. The fluctuation component following the vortex dipole oscillates with a global frequency selected by the upstream marginal absolute instability, and propagates obeying the local dispersion relation of the mean flow. By applying localized initial disturbances, a nonzero wave-packet density is achieved at the threshold state, suggesting a first order transition.

5 pages, 4 figures

References in corpus (3)

• The growth mechanism of turbulent bands in channel flow at low Reynolds numbers
• Streamwise decay of localized states in channel flow
• The Unified Transition Stages in Linearly Stable Shear Flows

Cited by in corpus (1)

• Pattern preservation during the decay and growth of localized wave packet in two-dimensional channel flow