A numerical study of fluid flow and heat transfer in eccentric curved annuli

In this article fluid flow and heat transfer in curved eccentric annuli are studied numerically. A second order finite difference method based on the Projection algorithm is implemented to solve the governing equations including the full Navier-Stokes, the continuity, and the energy equations in a toroidal coordinate system. For convenience a bipolar based toroidal coordinate system is employed to discretize the governing equations in the annulus domain using a uniform staggered grid which is required in finite difference methods. Considering hydrodynamically and thermally fully developed conditions, the effects of different physical parameters such as eccentricity, Dean number, curvature, Prandtl number on the flow field and thermal characteristics at different thermal boundary conditions are investigated in detail. It is also shown that in contrast to straight eccentric annuli, heat transfer rates can be augmented in the eccentric curved annuli comparing with the straight concentric annuli at the large dean numbers.