Subcritical Dynamo Bifurcation in the Taylor-Green Flow
Y. Ponty

Saturday 27 November 2010 by Ponty Yannick

In collaboration with J.-P. Laval, B. Dubrulle, F. Daviaud, and J.-F. Pinton

We report direct numerical simulations of dynamo generation for flow generated using a Taylor-Green
forcing. We find that the bifurcation is subcritical and show its bifurcation diagram. We connect the
associated hysteretic behavior with hydrodynamics changes induced by the action of the Lorentz force.
We show the geometry of the dynamo magnetic field and discuss how the dynamo transition can be
induced when an external field is applied to the flow.

 Ponty, Y., Laval, J.P., Dubrulle, B., Daviaud, F. and Pinton, J.F., "Subcritical Dynamo Bifurcation in the Taylor-Green Flow", Physical Review Letters, 99, p. 224501 (2007) (doi:10.1103/PhysRevLett.99.224501)


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Hysteris cycle of the sub-bifurcation
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Cover Page PRL 2007