Abstract
Transient growth due to non-normality is investigated for the Couette-Taylor problem with counter-rotating cylinders as a function of aspect ratio [eta] and Reynolds number Re. For all Re < or =500, transient growth is enhanced by curvature, i.e. is greater for [eta]<1 than for [eta]=1, the plane Couette limit. For fixed Re >130, it is found that the greatest transient growth is achieved for [eta] on the linear stability boundary. Transient growth is approximately 20% higher near the Couette-Taylor linear stability boundary at Re =310, [eta]=0.986 than at Re =310, [eta]=1, near the threshold observed for transition in plane Couette flow. For 106< Re <130, the greatest transient growth occurs for a value of [eta] between the linear stability boundary and one. For Re <106, the flow is linearly stable and the greatest transient growth occurs for a value of [eta] less than one. The energy in the optimal inputs is primarily meridional; that in the optimal outputs is primarily azimuthal. Pseudospectra are calculated for two contrasting cases. [PUBLICATION ABSTRACT]