×

zbMATH — the first resource for mathematics

Breaking of axisymmetry and onset of unsteadiness in the wake of a sphere. (English) Zbl 0977.76028
From the view point of nonlinear dynamical system theory the paper investigates the instabilities at the first stage of transition to turbulence in the wake flow after a sphere. The linear stability analysis and the full Navier-Stokes simulation based on a spectral method and on an azimuthal expansion are used to determine the primary instability threshold as well as the threshold of a secondary (Hopf-type) instability. The computed azimuthal modes (corresponding to the nonlinear instability modes) are used to explain the occurence of the bifid wake.

MSC:
76E30 Nonlinear effects in hydrodynamic stability
76D25 Wakes and jets
37N10 Dynamical systems in fluid mechanics, oceanography and meteorology
76F06 Transition to turbulence
PDF BibTeX XML Cite
Full Text: DOI