Global stability of swept flow around a parabolic body: Features of the global spectrum

Christoph J. Mack (1, 2) , Peter J. Schmid (2)

1 Department of Numerical Mathematics
2 LadHyX - Laboratoire d'hydrodynamique

The global temporal stability of three-dimensional compressible flow about a yawed parabolic body of infinite span is investigated using an iterative eigenvalue technique in combination with direct numerical simulations. The computed global spectrum provides a comprehensive picture of the temporal perturbation dynamics of the flow, and a wide and rich variety of modes has been uncovered for the investigated parameter choices: stable and unstable boundary-layer modes, different types of stable and unstable acoustic modes, and stable wavepacket modes have been found. A parameter study varying the spanwise perturbation wavenumber and the sweep Reynolds number reproduced a preferred spanwise length scale and a critical Reynolds number for a boundary-layer or acoustic instability. Convex leading-edge curvature has been found to have a strongly stabilizing effect on boundary-layer modes but only a weakly stabilizing effect on acoustic modes. Furthermore, for certain parameter choices, the acoustic modes have been found to dominate the boundary-layer modes. © 2011 Cambridge University Press.

Domains: Fluid mechanics [physics.class-ph]; Fluids mechanics [physics.class-ph]

Christoph J. Mack, Peter J. Schmid. Global stability of swept flow around a parabolic body: Features of the global spectrum. Journal of Fluid Mechanics, 2011, 669, pp.375-396. ⟨10.1017/s0022112010005252⟩. ⟨hal-00997979⟩