Numerical thermal-hydrodynamical modeling of a multi-bladed twisted tape inserted in a double-pipe heat exchanger: a comparative study

Abstract

Energy efficiency is a critical concern across various industries, and heat exchangers play a vital role in facilitating energy and heat transfer processes. Improving the performance of heat exchangers has become an important research focus. One popular passive technique for enhancing heat transfer in heat exchangers is the use of twisted tape inserts. While previous studies have explored the use of two-bladed twisted tapes, the potential benefits of employing multi-blade twisted tapes have not been extensively investigated. This numerical study addresses this research gap by examining the effects of using two- to five-bladed twisted tapes inserted in the inner tube of a heat exchanger. The current numerical study indicates that applying five-bladed twisted tape can improve the Nusselt number and performance evaluation criterion up to 44% and 14%, respectively, compared to that of a two-bladed twisted tape. Furthermore, the friction factor increases with an increased number of tape blades, particularly at higher twist ratios. Furthermore, a decrement in the twist ratio makes an increment in heat transfer, especially by raising the tape’s blades. The findings contribute to ongoing efforts to optimize heat exchanger design and improve energy efficiency through innovative passive techniques.