Estimation of the accuracy of PIV treatments for turbulent flow studies by direct numerical simulation of multi-phase flow

An original method, based on the direct numerical simulation (DNS) of two phase flows, is proposed to evaluate the capability for the PIV algorithms to measure turbulence properties. 3D particle fields are produced from the DNS and are used to generate synthetic images with well-defined flow properties. The imposed velocities in the synthetic images are evaluated thanks to different PIV algorithms and these results can be compared with the initial conditions of simulation. The first part of the present paper describes the synthetic image generator and the DNS of two phase flows. The second part is focused on the analysis of synthetic images of homogeneous turbulence by using two different PIV algorithms: a conventional PIV algorithm and a 'sub-pixel' iterative approach.