A numerical study of a novel discrete X-V baffle for heat transfer enhancement in duct heat exchangers

This study proposes a novel vortex generator, referred to as a discrete X-V baffle (DXVB), for enhancing heat transfer (H-T) in a square cross-section tube heat exchanger. The DXVB is developed by integrating the design concepts of a V-baffle and a V-orifice. A numerical approach based on the finite volume method is employed to investigate the thermal–hydraulic characteristics under turbulent flow conditions, with Reynolds numbers ranging from 3000 to 16,000. The effects of DXVB thickness and installation clearance are systematically examined. In addition, both co-current flow (+x direction) and counter-current flow (−x direction) configurations are considered. The results are presented in terms of dimensionless parameters, along with detailed analyses of flow structures (FS), H-T characteristics, and the underlying physical mechanisms occurring within the heat exchanger system. The findings reveal that the incorporation of DXVB significantly enhances the H-T rate, achieving a maximum increase of up to 6.29 times compared to a plain tube without inserts. Furthermore, the thermal enhancement factor (TEF), representing the overall performance, reaches a maximum value of 1.32.