Novel design of triangular delta winglet pair for heat transfer enhancement

International audienc

Heat transfer enhancement of inclined projected winglet pair vortex generators with protrusions

Heat transfer enhancement in parallel plate-fin heat exchanger is examined by performing three-dimensional numerical simulations of longitudinal vortex generators (VG) with protrusions. The turbulence is modeled using the shear-stress transport (SST) κ-ω model and validated with correlations and experimental data at Reynolds number equal to 4600. Hemi-spherical protrusions are inserted downstream two VG configurations: delta winglet type (DWP) and a new VG configuration named inclined projected winglet pair (IPWP), in various locations, leading to the definition of six different configurations. Based on the streamwise distribution of Nusselt number and friction coefficient criteria in addition to vorticity, the local performance is analyzed. Some VGs with protrusions are examined and show better performance relative to VGs standing alone. The present study highlights the different mechanisms involved in the convective heat transfer intensification by generating multiple interacting vortices while adding protrusions with low pressure drop penalty. Finally, it is found that the IPWP with protrusions, set downstream in the middle, bestows the best global performance with about 7.1% heat transfer enhancement compared to DWP configuration

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) κ-ω 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

Intensification des transferts par génération de vorticité

International audienc