Linear stability of channel entrance flow

Damien Biau (1)

1 UniGe - Università degli studi di Genova = University of Genoa

The spatial stability of two dimensional, steady channel flow is investigated in the downstream entry zone for both exponentially and algebraically growing disturbances. A model based on previous work is presented for the base flow which represents a small deformation of plane Poiseuille flow. The base flow evolution towards the fully developed state comes from the experimental and theoretical study of M. Asai and J.M. Floryan "Certain aspects of channel entrance flow", Phys. Fluids \textbf{16} (2004). This flow is found to be more stable than the parabolic Poiseuille flow. The most destabilizing base flow defect is then calculated using a variational method. The compromise between the destabilising effect of the defect, which diffuses downstream, and the instability growth is found to be insufficient to provoke transition in the downstream laminar flow.

Mots clés: Hydrodynamic instability; Channel flow

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Damien Biau. Linear stability of channel entrance flow. European Journal of Mechanics - B/Fluids, 2008, 27 (5), pp.579-590. ⟨10.1016/j.euromechflu.2007.11.004⟩. ⟨hal-00496410⟩