A THEORETICAL STUDY ON DIFFUSION IN PULSATING FLOW

A theoretical study has been made on the effect of pulsations in the flow field on interphase mass transfer. The phenomenon is of interest in studies of the cardiovascular system as well as in traditional engineering applications. The physical situation studied corresponds to fully developed flow in a long conduit with a periodic pressure gradient. The mass transfer problem was solved analytically for low amplitude pulsations for the two limiting cases of very small and very large frequencies. In addition, several numerical solutions were developed in the intermediate region where the asymptotic solutions are least accurate. The solutions taken together give a good quantitative overall view of the phenomenon. One of the most interesting and unexpected results is that at very low frequencies it is possible for a pulsatile flow to yield a lower interphase mass flux than a steady Poiseuille flow with the same velocity. Copyright © 1969 American Institute of Chemical Engineers