The Role of Helical and Non-Helical Drives on the evolution of Self-Consistent Dynamos
Abstract
In the self-consistent dynamo limit, the magnetic feedback on the velocity field is sufficiently strong to induce a change in the topology of the magnetic field. Consequently, the magnetic energy reaches a state of non-linear saturation. Here, we investigate the role played by helical and non-helical drives in the triggering and the eventual saturation of a self-consistent dynamo. Evidence of small-scale dynamo (SSD) activity is found for both helical and non-helical forcing, driven at the largest possible scale. Based on the spectrum analysis, we find that the evolution of kinetic energy follows Kolmogorov's law while that of magnetic energy follows Kazantsev's scaling. Also, we have verified that the aforementioned scalings remain valid for various magnetic Prandtl numbers (Pm). Statistical analysis is found to support our numerical finds.
Cite
@article{arxiv.2407.14810,
title = {The Role of Helical and Non-Helical Drives on the evolution of Self-Consistent Dynamos},
author = {Shishir Biswas and Rajaraman Ganesh},
journal= {arXiv preprint arXiv:2407.14810},
year = {2024}
}