Novel design of delta winglet pair vortex generator for heat transfer enhancement

Heat transfer is a naturally occurring phenomenon that can be greatly enhanced with the aid of vortex generators (VG). Three-dimensional numerical simulations of longitudinal vortex generators are performed to analyze heat transfer enhancement in parallel plate-fin heat exchanger. The shear-stress transport (SST) kappa-omega model is adopted to model the flow turbulence. Empirical correlations from the open literature are used to validate empty channel simulations. First, numerical simulations are conducted for the classical delta winglet pair (DWP) which is introduced as the reference case in this study. Then, an innovative VG configuration, named inclined projected winglet pair (IPWP), is examined and it shows superior performance relative to the DWP. The IPWP exhibits similar heat transfer rates than that of the DWP but with lower pressure drop penalty due to its special aerodynamic design. The local performance is analyzed based on the streamwise distribution of Nusselt number and friction coefficient criteria in addition to vorticity. This study highlights the different mechanisms involved in the convective heat transfer intensification by generating more vortices using more aerodynamic VG shape while decreasing the pressure drop penalty. (C) 2016 Elsevier Masson SAS. All rights reserved.