CFD analysis of a vertical tube with external helical fins in natural convection

Abstract

Convective heat transfer between a surface and the surrounding fluid in a heat exchanger has been a major issue and a topic of study for a long time. In this study, an attempt has been made to study the effect of various fin configurations on the total heat transfer from a vertical tube. The temperature contours, velocity vectors, surface nusselt number, total heat transfer rate from the fins as well as wall of the tube were calculated and plotted using ANSYS 13.0. The Navier-stokes equations were used to solve for the fluid flow inside the tube and the Boussinesq approximation was used to model the buoyancy effect. Aluminum was used as the base metal for the pipe as well as the fin material. The fluid surrounding the tube was air.
Three different configurations have been used in this analysis. The three configurations were compared on the basis of total heat transfer. It was found that the fin configuration with trapezoidal fins had the most heat transfer rate.