Numerical simulation of effect of convection-diffusion on oxygen transport in microcirculation

The entire process of oxygen transport in microcirculation by developing a 3D porous media model is calculated numerically with coupled solid deformation-fluid seepage-convection and diffusion . The principal novelty of the model is that it takes into account volumetric deformation of both capillary and tissues resulting from capillary fluctuation. How solid deformation, fluid seepage, and convection-diffusion combine to affect oxygen transport is examined quantitatively: (1) Solid deformation is more significant in the middle of capillary, where the maximum value of volumetric deformation reaches about 0.5%. (2) Solid deformation has positive influence on the tissue fluid so that it flows more uniformly and causes oxygen to be transported more uniformly, and eventually impacts oxygen concentration by 0.1%-0.5%. (3) Convection-diffusion coupled deformation and seepage has a maximum (16%) and average (3%) increase in oxygen concentration, compared with pure molecular diffusion. Its more significant role is to allow oxygen to be transported more evenly.