Fine Structure of a Directly Simulated Isotropic Turbulence

Abstract

The fine structure of the isotropic turbulence, which has recently been realized in a supercomputer by the authors, is studied at its fully-developed state. The geometrical relationship between vorticity-concentrated regions and high-strain regions and a variety of mutual orientations of the velocity and vorticity vectors in these regions are illustrated. A common exponential nature and a delicate difference of the space distributions of the velocity (longitudinal and lateral) gradients, along with the magnitude of vorticity and the square-root of local dissipation, are exposed.