Parametric study of vortex generators on a fin-and-tube heat exchanger

Heat exchangers are intended to be as efficient, inexpensive, lightweight, and small as possible. Consequently, the inclusion of flow control devices aimed at enhancing heat transfer in heat exchangers has emerged as a prominent research topic. This study focuses on investigating the impact of incorporating vane-type Vortex Generators (VGs) in a fin-and-tube heat exchanger. In contrast with previous studies, the VGs proposed on this study are lower than the fin pitch, leading to the generation of vortexes and enhancing heat transfer. To achieve this objective, several simulations are performed by means of Computational Fluid Dynamics (CFD), using various Reynolds numbers (Re) and angles of attack (& alpha;) of the VGs. These simulations aim to assess the hydraulic and thermal efficiency of the heat exchanger across different operating modes. In addition, the generated vortexes and temperature, pressure and velocity fields are analyzed; with the aim of obtaining a more comprehensive understanding of the flow characteristics within the heat exchanger. The findings show that the implementation of VGs, in comparison with the benchmark case which does not contain VGs, improves thermal performance in all the studied cases, achieving a maximum enhancement between 79% and 97%, depending on the Re; but it also reduces hydraulic performance. Nevertheless, by the implementation of VGs, a maximum overall performance increase between 13% and 59% is achieved, depending on Re. Considering both hydraulic and thermal performance, the results show that the greatest performance improvements are obtained with the lowest angles of attack. Additionally, an Artificial Neural Network (ANN) is developed and trained for modeling the tested case, showing that the best overall performance is obtained with Re = 500 and & alpha; = 11.33 & DEG;.