Flow Enhancement of Shear-Thinning Liquids in Capillaries Subjected to Longitudinal Vibrations

Application of sinusoidal vibrations in the longitudinal direction causes a significant enhancement in the flow rate of shear-thinning carboxymethylcellulose and polyacrylamide solutions inside capillaries. Depending on the vibration frequency and amplitude, flow enhancements of up to a factor of 9.6 have been realized. Video imaging of a tracer particle inside the tube provides insights into the liquid motion. In particular, it should be noted that the phase shift between the sinusoidal motion of the tube wall and the liquid inside the tube is of high importance in determining the flow enhancement factor.