Unsteady Flow through a Rotating Curved Channel with Rectangular Cross-Section

A numerical study is presented for the fully developed two-dimensional thermal flow of viscous incompressible fluid through a rotating curved rectangular duct of constant curvature delta=0.1. In this paper, a spectral-based computational algorithm is employed as the principal tool for the simulations, while a Chebyshev polynomial, collocation method as secondary tools. Numerical calculations are carried out over a wide range of the Taylor number 0 <= Tr <= 2000 and the Dean number 100 <= Dn <= 2000 for the Grashof number Gr = 500. The outer wall of the duct is heated while the inner wall is cooled. Unsteady flow structures are examined for the effects of rotation parameter and pressure-driven parameter, and it is found that the unsteady flow undergoes in the scenario 'Chaotic -> multi-periodic -> periodic -> steady-state', if Tr is increased in the positive direction. Contours of secondary flow patterns, temperature profiles and axial flow distribution are also obtained at several values of Tr, and it is found that there exist two-and multi-vortex solutions. It is also found that the temperature distribution is consistent with the secondary and axial vortices, and convective heat transfer is significantly enhanced as the secondary vortices become stronger.