FILM FLOW OF PSEUDOPLASTIC LIQUIDS ALONG AN OSCILLATING WALL

The film thickness of pseudoplastic liquids flowing down a vertical wa ll can be decreased by the longitudinal oscillations of the wall. This phenomenon is treated in the term of the flow enhancement which is co mmon in the flows in oscillating tube. The theoretical predictions of the flow rate enhancement are reviewed for the boundary layer and cree ping flow regimes. The experiments were done in the transient regime b etween these two asymptotic regimes. As high as five-fold decrease of the film thickness, which corresponds to the flow rate enhancements 10 (5), was measured with concentrated kaolin suspensions with the flow i ndex 0.15. Empirical correlations which describe the flow rate enhance ment and the film thickness of the liquids with the power law viscosit y function in the transient regime were found.