Investigations of the effect of circular perforations and V-cut on SLTT in DPHE: An experimental analysis using IoT approach

The objective of this research is to explore the characteristics of the mean Nusselt number, friction factor, and enhancement efficiency in a double pipe heat exchanger. The emphasis lies in using short twisted tapes featuring round holes and a V-shaped cut. To conduct the experiment, an IoT-based DPHE setup was employed. In the experiment, various twisted tape configurations were examined to investigate their impact on heat transfer and pressure loss. These configurations included a full-length twisted tape and three short-length tapes with different perforation diameters. The full-length tape, with a twist ratio of x/ b = 4, spanned throughout length of the tube. In contrast, the plain short-length tape and modified short-length tapes, with the same twist ratio, were inserted in the section’s entrance. The shorter inserts, with a length ratio (LR = ls/lf) of 0.50, were compared to the full-length tape. The experimental findings demonstrated that the short-length tapes with LR = 0.50 consistently exhibited lower thermohydraulic performance compared to full-length inserts. Specifically, within the Re range of 4000–24,000, Nusselt numbers and friction factors for the short inserts were approximately 11%, 9.1%, and 6.1% lower, and 20.6%, 16.1%, and 11.2% lower, respectively, compared to the full-length inserts.