3-dimensional CFD simulation and correlation development for circular tube equipped with twisted tape

Abstract

The current paper represents computatioal fluid dynamics (CFD) investigation and novel correlation development for a round tube having twisted tape inserts with various tape length ratio i.e., 0.29, 0.43, 0.57, and 1.0 at uniform wall heat flux boundary conditions. The different short-length tapes are used as a swirling flow system to produce a powerful swirl flow in the tube. The variations of pressure loss and heat transfer in the form of friction factor and Nusselt number have been investigated and graphically represented. The numerical results show that the tube having twisted tape with tape length ratio (LR) of 0.29, 0.43, 0.57, and 1.0 is more effective than the smooth tube in terms of Nusselt number and friction factor values. The resulting data is reduced into correlations using a linear stepwise regression algorithm. The developed equations for tube having twisted tape predict all the data for friction factor and Nusselt number within ±5% relative absolute deviation. The average deviation between developed and available experimental correlation is of the order of <±9%.