Enhanced diffusion induced in a tilted pipe: the role of diffusion-driven flow in enhancing mixing*

In this work, we identify and isolate an unexplored mechanism of solute dispersion in an inclined capillary pipe. Cracked micro channels may experience diffusion induced flows in the presence of density stratification.   Here, we explore the role of such flows in quantifiying the mixing they may produce.  We present a combination of theoretical and experimental anaylsis to calculated the effective Taylor diffusivity induced by such flows as a function of the various physical parameters including inclination angle, cross-sectional area, molecular diffusivity, fluid viscosity, and solute density gradient.