Vortex models of the fine scales of turbulence

We survey the current status, prospects and problems of vortex models of the fine scales of turbulence. We begin with the attempt by Synge and Lin in the 1940's to calculate the longitudinal velocity correlation for isotropic tubulence using an ensemble of Hill's spherical vortices. A discussion of models based on the Burgers vortex is followed by a detailed description of the use of an ensemble of randomly oriented stretched spiral-vortex solutions of the Navier-Stokes equations to predict/postdict several small-scale properties of stationary homogeneous tubulence at large wavenumber. These include the spectra of various quantities and the one-point velocity gradient statistics.