Numerical investigation of the thermo-hydraulic performance of DNA inspired double and triple helix wire coils

Abstract

In this study, DNA-inspired wire coil (WC) inserts, namely double wire coil (DWC) and triple wire coil (TWC), were proposed for promoting the thermo-hydraulic performance of a plain tube. Triangular-in-shape WC fitted tubes were modeled in Ansys Workbench and numerically solved in Ansys Fluent. WC inserts with pitches (0.056 m, 0.112 m, 0.168 m), side lengths (0.005 m, 0.006 m) and clearance distances (0.001 m, 0.002 m) were analyzed through a fully developed turbulent flow with the Reynolds number ranging from 6,406−26,647. Detailed model validations were performed using the empirical data and experimental studies in the literature and good agreements were statistically achieved. Results reveal that the proposed inserts can significantly increase the heat transfer performance and performance evaluation criterion (PEC) by almost up to fivefold and 103% compared to those of a plain tube, respectively. DWC increases the PEC by ∼1.1 times the SWC fitted tube while TWC can increase the PEC by ∼1.14 times. Increasing the number of WC beyond three would not add benefits to the PEC considerably.