Microscope PIV for velocity-field measurement of particle suspensions flowing inside glass capillaries

We assembled an experimental arrangement for the measurement of the velocit y field of glycerol suspensions, in the diametric plane, inside glass capil laries with internal diameter of the order of 200 mu m. Glass spheres of me an diameter of 10 mu m were used to seed the flow. The velocity fields were determined by the particle image velocimetry (PTV) method, whereby, in con trast to the usual implementations of this method based on light-sheet imag ing, a forwards-scattering technique with the entire volume flow illuminate d was used and the plane of interest was determined by the objective lens o f a microscope. Statistical analysis of acquired experimental results was p erformed and possible limitations of the proposed technique were investigat ed. The method, with its present implementation, was used to measure veloci ties up to 4 mm s(-1) and seems to be promising for similar measurements in glass capillaries or in microcirculation.