Performance Assessment and Empirical Correlation in a Heat Exchanger Square Duct with Diagonal Inserted Generators

A mathematical analysis of the heat transfer enhancement, thermal performance and flow configurations in a heat exchanger square duct with diagonal inserted plate vortex generators is presented. The 30o V–shaped baffles are modified and placed on the double sides of the thin plate or frame (with no plate) which inserted diagonally in the square duct. The effects of blockage ratio (b/H, BR), the pitch ratio (p/H, PR), flow direction (V–Downstream and V–Upstream) and configuration of inserting plate are investigated for Reynolds number based on the hydraulic diameter of the square duct, Dh, Re = 100 – 2000. The finite volume method applies for the computational domains. The numerical results show that the use of the diagonal inserted generators can help to increase heat transfer rates and thermal performance in the square duct higher than the smooth duct with no generators. The presences of the diagonal inserted generators not only increase heat transfer rates but also increase very enlarges pressure loss. The maximum thermal enhancement factor is around 3.25 at the highest Reynolds number. In addition, the use of the diagonal inserted generators can help to install and also comfortable to maintenance in the heat exchange duct.