Oscillating Ponomarenko dynamo in the highly conducting limit

Peyrot, Marine; Gilbert, Andrew; Plunian, Franck

Oscillating Ponomarenko dynamo in the highly conducting limit

Authors

Peyrot, Marine

Gilbert, Andrew

Plunian, Franck

Description

This paper considers dynamo action in smooth helical flows in cylindrical geometry, otherwise known as Ponomarenko dynamos, with periodic time dependence. An asymptotic framework is developed that gives growth rates and frequencies in the highly conducting limit of large magnetic Reynolds number, when modes tend to be localized on resonant stream surfaces. This theory is validated by means of numerical simulations.
12 pages, 4 figures