Asymmetric, helical and mirror-symmetric travelling waves in pipe flow

CCT Pringle, RR Kerswell

Research output: Contribution to journalArticle (Academic Journal)peer-review

91 Citations (Scopus)

Abstract

New families of three-dimensional nonlinear traveling waves are discovered in pipe flow. In contrast with known waves [H. Faisst and B. Eckhardt, Phys. Rev. Lett. 91, 224502 (2003); H. Wedin and R. R. Kerswell, J. Fluid Mech. 508, 333 (2004)], they possess no discrete rotational symmetry and exist at a significantly lower Reynolds numbers (Re). First to appear is a mirror-symmetric traveling wave which is born in a saddle node bifurcation at Re=773. As Re increases, "asymmetric" modes arise through a symmetry-breaking bifurcation. These look to be a minimal coherent unit consisting of one slow streak sandwiched between two fast streaks located preferentially to one side of the pipe. Helical and nonhelical rotating waves are also found, emphasizing the richness of phase space even at these very low Reynolds numbers.
Translated title of the contributionAsymmetric, helical and mirror-symmetric travelling waves in pipe flow
Original languageEnglish
Number of pages4
JournalPhysical Review Letters
Volume99
DOIs
Publication statusPublished - Aug 2007

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