Dynamics of a laminar flow past a rotating bullet-shaped body
Abstract
Numerical simulations are performed for laminar flow past a rotating bullet-shaped body of length-to-diameter ratio L / D = 2 , ranging the non-dimensional angular rotation velocity, Ω = ωR /u∞ , from 0 to 0 . 6 , and covering the Reynolds number range 320 < Re < 430 . Three transition patterns stand out as Ω increases on the parametric map Ω- Re . When Ω <= 0 . 3 , increasing rotation speeds have a stabilizing effect for the first transition, delaying the symmetry breaking bifurcation to higher values of Re , however it triggers the second bifurcation at lower Re than in the case of stationary bodies. Furthermore, the wake undergoes three different flow regimes as Re increases: axisymmetric, frozen (i.e. two counterrotating vortices aligned with the streamwise direction rotate around the axis with a different frequency than that of the body) and spiral flow. A different behavior has been observed in the range 0 . 3 <= Ω <= 0 . 5 where only a single transition exists. Finally, when Ω > 0 . 5 there are also two transitions, both leading to different swirling flows.
Supported by the projects DPI2008-06624-C02, P07-TEP02693 and P11-TEP5702.- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2011
- Bibcode:
- 2011APS..DFDE20004J