3-D reconstruction of velocity profiles in rectangular microchannels

Particle Image Velocimetry (PIV) is a non-intrusive technique widely used nowadays to experimentally obtain the velocity field of a flow. During the last decade, it has been adapted to microscale and μ-PIV is now a useful tool for providing information about microflows. One of the main differences between μ-PIV and PIV is relative the depth of field which is negligible at macroscale but which could become non-negligible compared with microchannels dimensions and could lead to a poor experimental accuracy. In this paper, we propose a way to obtain an accurate 3-D velocity profile from a series of 2-D μ-PIV data, when the depth of field is not negligible compared with the microchannel depth. The method is analysed and validated from virtual experiments for benchmark flows. The improvement is very noticeable and the method also allows to accurately determine the position of the walls and the real depth of field.