|
|
|
KTH /
Engineering Sciences /
Mechanics /
Research /
Publication list /
Publication information
Article information
Global stability of a jet in cross-flow
Abstract
A linear stability analysis shows that the jet in cross-flow is characterized by self-sustained global oscillations for a jet-to-cross-flow velocity ratio of three. A fully three-dimensional unstable steady-state solution and its associated global eigenmodes are computed by direct numerical simulations and iterative eigenvalue routines. The steady flow, obtained by means of selective frequency damping, consists mainly of a (steady) counter-rotating vortex pair (CVP) in the far field and horseshoe-shaped vortices close to the wall. High-
frequency unstable global eigenmodes associated with shear layer instabilities on the CVP and low-frequency modes associated with shedding vortices in the wake of the jet are identified. Furthermore, different spanwise symmetries of the global modes are discussed. This work constitutes the first simulation-based global stability analysis of a fully three-dimensional base flow.
|
|
|
