μPIV-Analysis of Taylor flow in micro channels

Micro particle imaging velocimetry (μPIV) has been used to characterize two-phase flows in micro channels. Phase internal flow in large segments as well as in small segments has been investigated for the contribution of interface friction to the formation of the internal flow field. According to experimental conditions (flow rate, volume ratio of the phases, channel path geometry, viscosity), the decisive contribution of either liquid/wall or liquid/liquid interface friction to the phase internal flow changes locally. This results in partially alternating internal flow directions between micro droplets and separation medium. For internal flow field evaluation, algorithms of PIV image analysis have been extended for algorithms of droplet recognition, mapping and transformation into a single coordinate system before displacement analysis. Simulations by computational fluid dynamics (CFD) are in good agreement with the measured flow fields.