New prospects for the Riga dynamo: Prediction of magnetic energy oscillations for a modified flow field

Starting from the present version of the Riga dynamo experiment with its rotating magnetic eigenfield dominated by a single frequency we ask for those flow modifications that would allow for a non-trivial magnetic field behaviour in the saturation regime. Increasing the ratio of azimuthal to axial flow velocity, numerically we obtain energy oscillations with a frequency below the eigenfrequency of the magnetic field. These new oscillations are identified as magneto-inertial waves that result from a slight imbalance of Lorentz and inertial forces. Increasing the azimuthal velocity further, or increasing the total magnetic Reynolds number, we find transitions to a chaotic behaviour of the dynamo.