Searching for the fastest dynamo: Laminar ABC flows

Development length of laminar magnetohydrodynamics pipe flows

In this article, a laminar magnetohydrodynamics (MHD) developing flow of an incompressible electrically conducting fluid subjected to an external magnetic field is considered. The aim of the study is to propose a correlation for computing the development length of the laminar MHD developing flow in a pipe. A numerical approach is considered to solve the problem. In the first step, the numerical...

Dynamo action in flows with cat’s eyes

The paper considers dynamo action in steady fluid flows having a cat’s eye stream line topology. The flows considered are two-dimensional, depending on x and y only, but have all three components of velocity and so can act as kinematic dynamos. The limit of large magnetic Reynolds number R is considered and numerical results are presented for the different types of magnetic mode that may be amp...

A unified description of anti-dynamo conditions for incompressible flows

A general type of mathematical argument is described, which applies to all the cases in which dynamo maintenance of a steady magnetic field by motion in a uniform density is known to be impossible. Previous work has demonstrated that magnetic field decay is unavoidable under conditions of axisymmetry and in spherical or planar incompressible flows. These known results are encompassed by a calcu...

Lagrangian chaos in an ABC-forced nonlinear dynamo

The Lagrangian properties of the velocity field in a magnetized fluid are studied using three-dimensional simulations of a helical magnetohydrodynamic dynamo. We compute the attracting and repelling Lagrangian coherent structures (LCS), which are dynamic lines and surfaces in the velocity field that delineate particle transport in flows with chaotic streamlines and act as transport barriers. Tw...

Novelty Detection in Laminar and Turbulent Flows