Global stability of swept flow around a parabolic body: The neutral curve

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

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

The onset of transition in the leading-edge region of a swept blunt body depends crucially on the stability characteristics of the flow. Modelling this flow configuration by swept compressible flow around a parabolic body, a global approach is taken to extract pertinent stability information via a DNS-based iterative eigenvalue solver. Global modes combining features from boundary-layer and acoustic instabilities are presented. A parameter study, varying the spanwise disturbance wavenumber and the sweep Reynolds number, showed the existence of unstable boundary-layer and acoustic modes. The corresponding neutral curve displays two overlapping regions of exponential growth and two critical Reynolds numbers, one for boundary-layer instabilities and one for acoustic instabilities. The employed global approach establishes a first neutral curve, delineating stable from unstable parameter configurations, for the complex flow about a swept parabolic body with corresponding implications for swept leading-edge flow. © 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: The neutral curve. Journal of Fluid Mechanics, 2011, 678, pp.589-599. ⟨10.1017/jfm.2011.158⟩. ⟨hal-00997980⟩