Numerical study of heat transfer enhancement through a circular tube fitted with and without rectangular cut twisted tape insert

Abstract

Abstract Numerical simulations have been carried out to investigate the heat transfer enhancement in a tube fitted with a rectangular cut twisted tape insert and compare the data with a smooth tube. For this purpose, CFD (Computational Fluid Dynamics) was utilized to simulate the three-dimensional model with appropriate boundary conditions. The numerical results show that the flow field can be adjusted and the thickness of boundary layer can be decreased by inserting the rectangular cut twisted tape insert so that the heat transfer can be enhanced in the tube. Water was used as the working fluid. The results obtained show an increase in Nusselt number as a result of increasing heat transfer rate for the tube provided with rectangular cut twisted tapes than the plain tube. The pressure drop across the tube wall for twisted tape with the rectangular cut is higher than the plain tube. This increase in the rate of heat transfer is due to the introduction of secondary swirl flow (due to twisted tape) along with the primary flow.