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 (My) 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 ≤ κ ≤ 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 (ΔPpenalty) is not increasingly dependent on interaction parameter when Re and κ remain constant.