Thermohydraulic performance analysis of tube heat exchanger using dual side serrated insert tape having triangular wings

Inserting a winglet-type turbulator at the center core part of the tube Heat Exchanger (HE) can significantly promote the heat transfer capacity. In this study, a dual-side serrated insert tape having triangular winglets was applied to experimentally analyze the influence of various configurations of this hybrid insert geometry on heat transfer and flow characteristics. In many previous research articles, the serrated tapes and winglets were used separately, but the novelty of this work is to study the effect of a hybrid insert geometry (combination of serration on tape and perforated winglets) on the thermohydraulic performance of tube HE. To deeply analyze the overall performance of the HE, different arrangements of triangular wings such as 1) Forward Flow (FF), 2) Backward Flow (BF), 3) Alternate-axis Forward Flow (A-FF), and 4) Alternate-axis Backward Flow (A-BF) has been considered based on the direction of flow. Different geometrical parameters such as wing pitch ratio (P/W), wing width ratio (w/W), wing depth ratio (d/W), serration width ratio (x/W), and perforation index (PI) are considered for the present study. The Reynolds Number (Re) varies from 10000 to 30000. The experimental findings indicate that there are significant increases in Nusselt number (Nu), friction factor (f), and Thermohydraulic Performance Factor (TPF) up to 2.43 times, 12.41 times, and 1.05, respectively as compared to the plain tube heat exchanger. This hybrid insert geometry offers more heat transfer and moderate friction factor as compared to conventional turbulators used in tube-type HEs.