The present paper investigates non-isothermal flow characteristics through a rotating curved rectangular duct, where co-existence of the rotational forces and fluid temperature gradients leads to the emergence of rotation-induced buoyancy effects. A spectral-based numerical scheme is employed as the principal tool for the simulation while Chebyshev polynomial and collocation method as the secondary tools. The outer wall of the duct is heated while the inner wall cooled, the top and bottom walls being thermally insulated. The emerging parameters controlling the flow characteristics are the rotation parameter, i.e., the Taylor number Tr ranging 0 to 2000, the Grashof number Gr = 100, the Prandtl number Pr, the aspect ratio, and the pressure-driven parameter, i.e., the Dean number Dn between 100 and 1000. The flow structures are examined under combined action of the centrifugal, Coriolis and buoyancy forces. As a result, asymmetric 2-cell structures are computed for small values of Tr while asymmetric 6-cell structures for large Tr. Unsteady flow characteristics show that the flow undergoes in the scenario ‘chaotic→ multi-periodic → periodic→ steady-state’, if Tr is increased in the positive direction. Typical 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 asymmetric two- to multi-vortex solutions. Heating the outer wall is found to generate a significant temperature gradient at the outer concave wall.
Islam, Md. Zohurul; Islam, Md. Saidul; and Mondal, Rabindra Nath
Spectral Numerical Calculation of Non-isothermal Flow through a Rotating Curved Rectangular Duct with Moderate Curvature,
Applications and Applied Mathematics: An International Journal (AAM), Vol. 11,
3, Article 4.
Available at: https://digitalcommons.pvamu.edu/aam/vol11/iss3/4