Toward small-scale laboratory dynamos

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• Vassilios Dallas, Oxford
• Thursday 04 October 2018, 13:00-14:00
• Watson LTB.

If you have a question about this talk, please contact Fabian Spill.

The existence of planetary and stellar magnetic fields is attributed to the dynamo instability, the mechanism by which a background turbulent flow spontaneously generates a magnetic field by the constructive refolding of magnetic field lines. Many efforts have been made by several experimental groups to reproduce the dynamo instability in the laboratory using liquid metals. However, so far, unconstrained dynamos driven by turbulent flows have not been achieved in the intrinsically low magnetic Prandtl number $P_m$ (i.e. $Pm = Rm/Re << 1$) laboratory experiments. In this seminar I will demonstrate that the critical magnetic Reynolds number $Rm_c$ for turbulent dynamos in the low $P_m$ limit can be significantly reduced if the flow is submitted to global rotation. Even for moderate rotation rates the required energy injection rate can be reduced by a factor more than 1000. Our finding thus points into a new paradigm for the design of novel liquid metal dynamo experiments.

This talk is part of the Applied Mathematics Seminar Series series.

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• Applied Mathematics Seminar Series
• School of Mathematics Events
• Watson LTB

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