Building upon the prior research targeting the laminar breakdown mechanisms associated with stationary crossflow instability over a swept-wing configuration, this paper investigates the secondary instability of traveling crossflow modes as an alternate scenario for transition. For the parameter range investigated herein, this alternate scenario is shown to be viable unless the initial amplitudes of the traveling crossflow instability are lower than those of the stationary modes by considerably more than one order of magnitude. The linear growth predictions based on the secondary instability theory are found to agree well with both parabolized stability equations and direct numerical simulation, and the most significant discrepancies among the various predictions are limited to spatial regions of relatively weak secondary growth, i.e., regions where the primary disturbance amplitudes are smaller in comparison to their peak values. Nonlinear effects on secondary instability evolution are also investigated and found to be initially stabilizing when they first come into play.


Mechanical and Aerospace Engineering

Research Center/Lab(s)

Center for High Performance Computing Research

Keywords and Phrases

Computational Fluid Dynamics; Forecasting; Swept Wings; Breakdown Mechanism; Cross-Flow Instabilities; Crossflow Vortices; Disturbance Amplitudes; Nonlinear Effect; Parabolized Stability Equations; Secondary Instability; Stationary Modes; Stability

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

File Type





© 2014 American Institute of Physics Inc., All rights reserved.

Publication Date

01 Jan 2014