Mass transfer between solid spheres and oscillating fluids — A critical review

Relative oscillatory motion between solid particles and a fluid increases the rate of interphase mass transfer due to the establishment of secondary flows (acoustic streaming). A critical survey of published data shows that mass transfer is well correlated by a theoretically founded dimensionless relation of the form\documentclass{article}\pagestyle{empty}\begin{document}$$ \bar {N_{ah}} = K N_{Re}^{a}(A/D)^{b}N_{Sc}^{d} $$\end{document}where K, a, b and d depend on the Schmidt number. The equation successfully correlates experimental data for both gases and liquids over a range of frequencies F < 1 Hz to F ∼ 10 6 Hz, provided the amplitude to diameter ratio A/D is below 0.75. At higher values of this parameter, \documentclass{article}\pagestyle{empty}\begin{document}$ \bar N_{Sh} $\end{document} is better predicted by a quasi‐steady model which no longer depends on A/D.