Abstract
We present the results of an experimental study on the transition to spiral vortices in flow between concentric counter-rotating cylinders in the presence of an axial through-flow, i.e., in spiral Poiseuille flow. The experiments were performed in an apparatus having an aspect ratio Gamma=L/d=22.8 ( L axial length, d gap width between cylinders) and end plates enabling an in and outflow of mass. As a result of an applied axial through-flow the "classical" Hopf bifurcation to spiral vortices (SPI) splits up and a primary and secondary branch of down and upstream propagating SPI, respectively, as well as a transient quasiperiodic flow appear. Downstream propagating SPI resulting from the primary supercritical Hopf bifurcation are either convectively or absolutely unstable. The bifurcation structure observed in this open flow experiment is in qualitative agreement with predictions from theory of Hopf bifurcation with broken reflection symmetry [J. D. Crawford and E. Knobloch, Nonlinearity 1, 617 (1988)] and also in quantitative agreement with results from recent numerical calculations [A. Pinter, M. Lücke, and C. Hoffmann, Phys. Rev. E 67, 026318 (2003); C. Hoffmann, M. Lücke, and A. Pinter, Phys. Rev. E 69, 056309 (2004)].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.