Comment on "Transition in shear flows. Nonlinear normality versus non-normal linearity"

Authors: Henningson, D.S.H.
Document Type: Article
Pubstate: Published
Journal: Phys. Fluids
Volume: 8   2257-2258
Year: 1996


In a recent paper Waleffe (see ibid., vol.7, p.3060 (1995)) offers a critique of some recent work advocating transient growth as a key element in the (subcritical) transition process in shear flows. As an alternative Waleffe puts forward an interesting problem to describe his view of the nonlinear regeneration process necessary for self-sustained turbulence in these flows. However, it seems that Waleffe has to some extent overlooked the aim and implications of previous work dealing with the linear mechanisms involved in the transition process. The present paper aims at clarifying these issues.