Influence of conical strip inserts in heat transfer enhancement under transition flow

The performance of the concentric tube heat exchangers can be increased due to the swirl flow generation caused by the inserts which exchange heat in an effective manner. Many researchers have studied the thermal behaviour of different types of inserts, such as twisted tape and wire coil, with different geometries. This work dealt with the heat transfer and friction factor behaviour of newly fabricated staggered and non-staggered conical strip insets. The conical strip insert produces much swirl flow corresponding to the twist ratios (Y = 2, 3 and 5). The experimental results are in good agreement with the correlations developed for Nusselt number and friction factor with the help of regression analysis. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.