title: Transient growth in Taylor-Couette flow of a Bingham fluid.
abstract: In this paper we investigate linear transient growth of perturbation energy in Taylor-Couette flow of a Bingham fluid. The effects of yield stress on transient growth and the structure of the optimal perturbation are mainly considered for both the wide-gap case and the narrow-gap case. For this purpose we complement the linear stability of this flow subjected to axisymmetric disturbances, presented by Landry et al. [M. P. Landry, I. A. Frigaard, and D. M. Martinez, J. Fluid Mech. 560, 321 (2006)], with the transient growth characteristics of both axisymmetric and nonaxisymmetric perturbations. We obtain the variations of the relative amplitude of optimal perturbation with yield stress, analyze the roles played by the Coriolis force and the additional stress in the evolution of meridional perturbations for the axisymmetric modes, and give the explanations for the possible change of the optimal azimuthal mode (featured by the maximum optimal energy growth G(opt)) with yield stress. These results might help us in the understanding of the effect of fluid rheology on transient growth mechanism in vortex flows.
authors.affiliation: Low Speed Aerodynamics Institute, China Aerodynamics Research and Development Center, Mianyang, Sichuan 622762, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Wan
authors.affiliation: Low Speed Aerodynamics Institute, China Aerodynamics Research and Development Center, Mianyang, Sichuan 622762, China.
authors.forename: Wei-Guo
authors.initials: WG
authors.lastname: Zhang