Large eddy simulation of fully-developed flow in a helical segmented-fin tube bundle

Abstract

The Large Eddy Simulation approach was used to perform a numerical simulation of a flow around a circular tube bundle. The model is based on numerical tools, such as the immersed boundary technique and the extrapolation of pressure in the solid region of the tube, to represent a helical segmented-fin tube geometry. The simulation was conducted in an area away from the boundaries of the tube bundle, where the flow is fully-developed, and the use of periodic boundary conditions was possible. The mean velocity and turbulence values of the results and experimental data were compared and showed good general agreement. From the instantaneous results, it was possible to observe and study different turbulent structures presented in the flow. Two counter-rotating horseshoe vortices were identified in the space between the fins, which can improve heat transfer. Furthermore, a relevant transfer of momentum in the inter-segment space and contiguous zones was observed.