The Effect of Aspect Ratio On Taylor Dispersion in Oscillatory Poiseuille Flow in Rectangular Channels

The primary purpose of this study is to consider the effect of channel side walls on axial dispersion of solute plugs in oscillating flows. We introduce Fourier expansion of the three dimensional velocity profiles which permits the analytical evaluation of dispersion in three dimensional channels. We also identify the relevant time scales that separate various regime involved. We describe the general behavior of dispersion for low, medium and fast oscillations of flow. Also, we determine the effect of the presence of the corners on dispersion by comparing the results obtained from the exact expressions developed in this study with the asymptotic expressions obtained by Watson which neglect the presence of the corners.