| Three different approaches are used to study the laminar flow transitions, instabilities, and combined free and forces convective heat transfer problems for fully developed flows in rotating, curved channels with circular and rectangular cross sections.; In particular, a three-parameter regular perturbation method and a finite-volume numerical method are developed to solve the governing equations for the flow and heat transfer in channels with simultaneous curvature, rotation and heating/cooling. The perturbation method is for the circular tubes, and the numerical method for the rectangular channels. In these two parts of the work, we constrain ourselves to the steady, hydrodynamically and thermally fully developed flow under the condition of uniform wall heat flux with peripherally uniform wall temperature. We also confine ourselves to examine the symmetric flows with respect to the horizontal center plane of the channel by imposing a symmetric condition on the plane in our numerical scheme. The results cover the nature of the flow transition and its effect on the flow resistance and combined free and forced convective heat transfer for both heating and cooling cases under positive or negative rotations.; Using air as the fluid, the flows in channels with curvature and/or rotation are visualized in terms of end-view at the exit of the test sections through injecting smoke into the flows. In this part of the work, we also confine ourselves to the fully developed flows, and focus our attention on the phenomena due to the stabilizing/destabilizing influence of the curvature and/or rotation. Several test sections are used, and the results shown here are some typical ones for the four test sections. |
