Digital image velocimetry

Abstract

Digital image velocimetry is proposed for the measurement of the instantaneous velocity fields of time dependent flows. This technique improves the flow measurement by eliminating some of the restrictions on existing optical methods (i.e., laser speckle velocimetry and particle image velocimetry). Among these restrictions are the limited dynamic range of the velocity measurement, directional ambiguity of the velocity vector, and the difficulty of a real-time capability. The present technique greatly enhances the dynamic range of the velocity measurement and unequivocally determines the direction of the velocity vector.