CFD Simulation of Heat Transfer and Friction Factor Augmentation in a Circular Tube Fitted with Elliptic-Cut Twisted Tape Inserts

Abstract

This paper presents the application of a mathematical model for simulation of the swirling flow in a tube induced by elliptic-cut and classical twist tape inserts. Effects of the twist ratio (y=2.93, 3.91, and 4.89) and cut depth (w=0.4, 0.8, and 1.4 cm) on heat transfer enhancement (Nu) and friction factor (f) in laminar flow are numerically investigated. The simulation is carried out using commercial CFD package (FLUENT-6.3.26) to grasp the physical behaviour of the thermal and fluid flows of a constant heat-fluxed tube fitted with elliptic-cut twist tape in the laminar flow regime for the Reynolds number ranging from 200 to 2100. The simulated results matched the literature correlations of plain tube for validation with 8% variation for Nusselt number and 10% for friction factor. The results show that the heat transfer rate and friction factor in the tube equipped with elliptic-cut twist tape (ECT) are significantly higher than those fitted with classical twist tape (CTT). Moreover the results also reveal that the Nusselt number and the friction factor in the tube with elliptic-cut twisted tape (ECT) increase with decreasing twist ratios (y) and cut depths (w).

A Conjugate Heat Transfer Analysis of a Triangular Finned Annulus Based on DG-FEM

“…Iqbal et al [18] proposed many optimal fin shapes in FDP. Salman et al [19] numerically presented the heat transfer enhancement in a tube induced by elliptic-cut and classical twist tape (ECT). Their results showed that the performance of ECT is better than classical twist tape.…”

Turbulent Forced Convection and Heat Transfer Characteristic in a Circular Tube with Modified-Twisted Tapes

“…They concluded that the heat transfer and friction loss tend to increase around 12-52% and 5-28%, respectively. Salman et al [10] presented heat transfer augmentation in a circular tube with elliptic-cut twisted tape (ECT) for laminar flow, Re = 200-2100. They claimed that the ECT in the tube heat exchanger provides higher heat transfer rate and thermal performance than the general twisted tape.…”

Comparative Studies on Thermal Performance of Conic Cut Twist Tape Inserts with SiO2and TiO2Nanofluids

“…Their results elaborated that the parabolic cut twist tape of twist ratio = 2.93 and cut depth = 0.5 with 4% CuO nanofluid offers about 10% enhancement for the Nusselt number than that of classical twisted tape at the same conditions. Salman et al [26] reported an application of a mathematical model of the heat transfer enhancement and friction factor characteristics of water in constant heat-fluxed tube fitted with one side elliptical cut twisted tape inserts with twist ratios ( = 2.93, 3.91, and 4.89) and different cut depths ( = 0.4, 0.8, and 1.4 cm) under laminar flow using FLUENT version 6.3.26. The results elaborated that the enhancement of heat transfer rate and the friction factor induced by elliptical cut twisted tape inserts increases with the Reynolds number and decreases with twist ratio.…”