Statistical analysis of pulsating non-Newtonian flow in a corrugated channel using Lattice-Boltzmann method

Abstract

Pulsating non-Newtonian flow in a corrugated channel was studied by using the Lattice Boltzmann Method (LBM) and utilizing the Boundary Fitting Method (BFM). A wide range of fluctuation amplitudes of pulsating flow was studied (0≤Apulse≤0.35) where Apulse=0 represents the steady flow. Various Reynolds numbers (50, 100, 150 and 200) and power law indices (0.6, 0.8, 1.0, 1.2 and 1.4) were also investigated with the Strouhal number set to 0.25. Spatial and temporal variations of streamlines, shear stress contours, recirculation zones, and skin-friction factor and velocity profiles were analyzed when non-Newtonian behavior transitions from shear-thinning to shear-thickening. Results demonstrated that skin friction factor is directly proportional to the power-law index and indirectly related with the Reynolds number. Plug-like velocity profiles are formed when fluid shows pseudoplastic behavior. Pulse amplitude, power-law index and Reynolds number were identified as key parameters affecting the behaviors of the pulsating flow. Fidelity of the numerical method was verified for both Newtonian and non-Newtonian regimes by comparison with available analytic solutions.