Numerical Investigation of Thermo-Hydraulic Features of Viscoplastic Flow in Wavy Channels

In the present work, the thermo- hydraulic characteristics are studied for a laminar viscoplastic flow through raccoon and serpentine type wavy channels. The results are presented by varying Bingham number (Bn), power-law index (n), Reynolds number (Re), dimensionless amplitude, and wave number in the physically justified ranges. It is found that the size of the recirculatory zone decreases with Bn and the zone disappears at the higher Bn values. The topology of the yielded-unyielded region highly depends on the geometry and the range of Bn. Moreover, the value of average Nusselt number decreases with n. With the increase in Bn, average Nusselt number gradually decreases up to a critical Bn value and then increases sharply at higher Bn values. Interestingly, the wavy channel is only advantageous at smaller Bn values up to a critical limit. The variation of performance factor (PF) strongly depends on the combined effect of rheological and geometrical parameters. Besides, results for raccoon and serpentine channels are highly dependent on the ranges of amplitude, wave number, Bn, and n.