Numerical simulation of oxygen mass transfer in a compliant curved tube model of a coronary artery.

Arterial wall transport of blood-borne oxygen is essential for superficial arterial wall metabolism. The unique geometry and hemodynamics of coronary arteries curved over the heart surface may alter the O2 transport pattern and lead to abnormalities of O2 tension at the inner wall (epicardial surface) which may contribute to atherogenesis. This study focused on O2 transport in a compliant model of a curved coronary artery. A three-dimensional finite element model with moving boundaries was setup to simulate physiological flow and O2 transport in coronary arteries. The full Navier-Stokes equations and the coupled conservation of species equation were solved simultaneously for typical coronary flow characteristics (aspect ratio=10, diameter variation=6%, mean Reynolds number= 150, unsteadiness parameter=3, Schmidt number=2,700). The results indicate a large difference in O2 wall flux (Sherwood number [Sh]) between the outside (Sh about 55) and inside (Sh about 2) walls and imply that O2 transport at the inner wall could be limited by the fluid phase.