Pulsating flow and heat transfer analysis around a heated semi-circular cylinder at low and moderate Reynolds numbers

A numerical analysis was carried out to examine the effect of pulsating flows around a semi-circular (heated) cylinder placed in a horizontal confined empty channel. The heat transfer induced as an outcome of non-zero mean sinusoidally varying flow past a semi-circular cylinder was investigated. For this purpose, computations are carried out for the following range of parameters: wall confinement (or blockage ratio, beta) = 25%; Prandtl number (Pr) = 7 (water as a working fluid); Reynolds number (Re) = 10-100; Strouhal number (St) = 0-2; and amplitude of oscillation (A) = 0-0.6. The current situation is numerically investigated by solving the continuity, momentum and energy equations using the finite volume method-based solver Ansys Fluent. Results in terms of total drag coefficient and Nusselt number have been presented and discussed. The nature of flow for each considered case is reported. The flow (streamlines) and thermal (isothermal contours) patterns have been analyzed. The maximum augmentations of about 22 and 10% were obtained in drag coefficient and Nusselt number, respectively. It is noteworthy that amongst all the cases studied, an appreciable amount of augmentation is observed when St = 1 and A = 0.6 (with respect to the case of non-pulsating flow i.e. St = 0).