Dynamic ranges of velocity and spatial resolution of particle image velocimetry

Abstract

To observe instantaneous fields of vorticity and rate-of-strain using PIV (particle image velocimetry) measurements of the velocity field, it is necessary to achieve maximum dynamic ranges in space and in velocity while simultaneously making accurate, low-noise measurements for the differentiation process. In this paper the dynamic ranges achievable with PIV are established in the context of the super-resolution algorithm described previously which seeks to extract the maximum possible information from a particle image field. Bounds on the dynamic spatial range and the dynamic velocity range are established in terms of optical parameters, and simple rules are derived for optimum design of PIV optical systems for various types of image recording media.