A Computational Study on Fluid Flow and Energy Distribution through a Bending Duct with Longitudinal Vortex Generation

Abstract

Since studies on fluid flow and energy dissemination through a bending duct (BD) plays prodigious contribution to both engineering and industrial standpoint, scientists have paid considerable attention to disclose new features of fluid flow through a BD. Taking this factor into account, the current work explores a computational approach on flow features and energy distribution through a bending rectangular duct of curvature 0.001 applying a spectral-based numerical scheme over a wide domain of the Dean number 0 < Dn ≤ 3000.The geometry is such that the bottom and outer side walls are thermally heated while the other walls are kept in room temperature. Newton-Raphson iteration method (N-R method) is adopted to inspect the branching structure of steady solutions (SS) which explores that there exist four branches of asymmetric steady solutions comprising 2- to 14-vortex solutions. The axial and secondary velocity distribution for each branch is investigated through different grid points by using different values of Dn. Unsteady flow characteristics are analyzed exquisitely by performing time-advancement of the solutions and flow transition is well determined by analyzing power spectrum (P-S) of the solutions. Axial flow, secondary flow, and temperature profiles have been depicted in accordance with Dn to wander the flow pattern, and it is predicted that the time-dependent flow (TDF) consists of asymmetric 2- to 10-vortex solutions. Finally, convective heat transfer (CHT) is analyzed by acquiring temperature contours for various types of physically realizable solutions. The study also demonstrates that centrifugal force comprehensively influences the fluid nature of the bending channel and CHT is more intensified due to chaotic phenomena of the flow.