Magnetic field generation by pointwise zero-helicity three-dimensional steady flow of an incompressible electrically conducting fluid.

摘要: We introduce six families of three-dimensional space-periodic steady solenoidal flows, whose kinetic helicity density is zero at any point. Four are analytically defined. Flows in four have spectrum. Sample flows from five used to demonstrate numerically that neither nor spectrum prohibit generation large-scale magnetic field by the two most prominent dynamo mechanisms: α-effect and negative eddy diffusivity. Our computations also attest such often generate small-scale for sufficiently small molecular These findings indicate not quantities controlling properties a flow regardless whether scale separation present or not.