Application of GDQ method for study of mixed convection in horizontal eccentric annuli

A generalized differential-integral quadrature (GDQ) discretization technique was used to solve a mixed heat convection problem in a body-fit coordinate system in its primitive variables form. A special treatment of the boundary condition to satisfy the continuity and momentum equations along the boundaries with the implementation of the GDQ method was investigated. Comparisons with the experimental and numerical results of other investigators are presented and discussed. In contrast with the existing published results, this highly accurate method was able to reveal extremely weak net circulation around the outer cylinder. In the horizontal annulus with the mixed heat convection problem the combination of unbalance of buoyancy and centrifugal forces causes net circulation. The net circulation decreases and approaches to zero with the rise of Rayleigh number, and it reaches its minimum value with high eccentricity when the inclination angle of eccentricity is pi.