Numerical Investigation of Triangular Y-Shaped Cut Twisted Stripe Insertion on Improving the Performance of Heat Exchangers

Abstract

Passive thermal performance has been the subject of significant study interest lately, with metal inserts being recognized as an effective method for boosting it. Nevertheless, there has been a limited investigation into Y-shaped inserts with diverse geometric configurations. A numerical study was approved to explore the optimization of heat transfer. in a high-temperature circular tube using Y-shaped inserts. The analysis considered two scenarios: one without any twisting, and another with Y-shaped inserts that had an axial twist and a twisted ratio of 2 along the edge. The Ansys 2022-R2 module was utilized to do calculations using the limited volume approach, employing the k-ε turbulence model. The study involved exposing a pipe segment with dimensions of 1.5 m in length and 68 mm in diameter to a steady heat flux of 1000 W/ m ² applied to the pipe wall. During the analysis, air is used as the fluid used for work, with the Reynolds values (Re) vary from 3000 to 21000., inclusive, in increments of 3000. The findings indicate that the optimal the values of the Nusselt number (Nu), reaching up to 128.14, can be attained at a Reynolds number (Re) of 21000 for Y-shaped designs with a twisted configuration. However, in comparison to a smooth tube, the values of the Nusselt number (Nu) increased by a factor of 5.68, with a coefficient of friction (f) of 0.029 and a Thermal Performance Evaluation (TPE) of 2.147, suggesting higher thermal performance.