All Outputs (4)

The nature of mean-field generation in three classes of optimal dynamos (2020)
Journal Article
Brandenburg, A., & Chen, L. (2020). The nature of mean-field generation in three classes of optimal dynamos. Journal of Plasma Physics, 86(1), Article 1905860110. https://doi.org/10.1017/s0022377820000082

In recent years, several optimal dynamos have been discovered. They minimize the magnetic energy dissipation or, equivalently, maximize the growth rate at a fixed magnetic Reynolds number. In the optimal dynamo of Willis (Phys. Rev. Lett., vol. 109,... Read More about The nature of mean-field generation in three classes of optimal dynamos.

Optimal kinematic dynamos in a sphere (2020)
Journal Article
Luo, J., Chen, L., Li, K., & Jackson, A. (2020). Optimal kinematic dynamos in a sphere. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 476(2233), Article 20190675. https://doi.org/10.1098/rspa.2019.0675

A variational optimization approach is used to optimize kinematic dynamos in a unit sphere and locate the enstrophy-based critical magnetic Reynolds number for dynamo action. The magnetic boundary condition is chosen to be either pseudo-vacuum or per... Read More about Optimal kinematic dynamos in a sphere.

A trio of simple optimized axisymmetric kinematic dynamos in a sphere (2019)
Journal Article
Holdenried-Chernoff, D., Chen, L., & Jackson, A. (2019). A trio of simple optimized axisymmetric kinematic dynamos in a sphere. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 475(2229), Article 20190308. https://doi.org/10.1098/rspa.2019.0308

Planetary magnetic fields are generated by the motion of conductive fluid in the planet's interior. Complex flows are not required for dynamo action; simple flows have been shown to act as efficient kinematic dynamos, whose physical characteristics a... Read More about A trio of simple optimized axisymmetric kinematic dynamos in a sphere.

The optimal kinematic dynamo driven by steady flows in a sphere (2018)
Journal Article
Chen, L., Herreman, W., Li, K., Livermore, P., Luo, J., & Jackson, A. (2018). The optimal kinematic dynamo driven by steady flows in a sphere. Journal of Fluid Mechanics, 839, 1-32. https://doi.org/10.1017/jfm.2017.924

We present a variational optimization method that can identify the most efficient kinematic dynamo in a sphere, where efficiency is based on the value of a magnetic Reynolds number that uses enstrophy to characterize the inductive effects of the flui... Read More about The optimal kinematic dynamo driven by steady flows in a sphere.