Numerical study of fluid flow and heat transfer in a circular tube with Trapezoidal-cut twisted tape inserts

This work examines the fluid flow, heat transfer, and thermal hydraulic performance of turbulent flow through a horizontal pipe integrated with TT that has various cut shapes using numerical analysis. In the current investigation, trapezoidal-cut geometry with single and double cuts is adopted. Three-dimensional simulations have been validated using experimental data from the literature. The equations have been solved using the RNG k-ε model and the finite volume method (FVM). With three distinct types of twisted tape (PT, SC, and DC) and TR (4.0, 6.4, and 8) for a heat flux of 5000 W m⁻², the computational findings have been carried out in the range of Reynolds numbers 4000 ≤ Re ≤ 8000. Impact of these factors on Nusselt number, friction factor, and thermal performance are explored and compared to plain pipe under similar conditions. The addition of trapezoidal-cut TTs leads to enhanced mixing of fluid due to swirl flow generation. The result shows that average Nusselt number and friction factor are functions of TR. The thermal performance factor (TPF) for double-cut trapezoidal TT is about 1.2–1.65 which is maximum compared to single-cut and plain TT inserts.