Effect of magnetic obstacle on fluid flow and heat transfer in a rectangular duct

The vortex dynamics behind various magnetic obstacles and characteristics of heat transfer are investigated using a three-dimensional model. In the numerical study, the magnet width (M-y) is alterable to investigate the instability, Strouhal number, wake structure behind various magnetic obstacles and percentage increment of the overall heat transfer for a wide range of constrainment factors (0.08 <= kappa <= 0.26), Reynolds numbers (400 <= Re <= 900) and interaction parameters (9 <= N <= 15). For all constrainment factors, the fundamental frequency (f) is uniform for a particular value of Reynolds number. Downstream cross-stream mixing due to vortex shedding enhances the wall-heat transfer and the maximum value of percentage increment of the overall heat transfer (HI) is about 20.2%. However, the pressure drop penalty (Delta P-penalty) is not increasingly dependent on interaction parameter when Re and kappa remain constant (C) 2014 Elsevier Ltd. All rights reserved.