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Benoît PIER
Laboratoire de mécanique des fluides et d'acoustique, École centrale de Lyon – CNRS – Université Claude-Bernard Lyon 1 – INSA, 36 avenue Guy-de-Collongue, 69134 Écully cedex, France
Journal of Fluids and Structures 41, 43–50 (2013)
The flow past a sphere rotating about an axis aligned with the streamwise direction is numerically investigated. The dynamics is governed by the incompressible Navier–Stokes equations and depends on two control parameters: the Reynolds number Rey and rotation rate Omega The present investigation systematically covers the range Rey<=350 and Omega<=2. First, the axisymmetric steady base flow (whether stable or not) is computed for all values of the control parameters. Then, after linearization of the equations about the base flow, the growth rates and frequencies of the leading eigenmodes are obtained. Fully nonlinear direct numerical simulations yield the detailed flow fields and hydrodynamic forces acting on the sphere. Different wake modes (low-frequency periodic helical, quasiperiodic shedding and high-frequency periodic helical) are identified and their characteristic frequencies precisely determined.
hal-00733514
2013b_pier_jfs.pdf