Louver finned heat exchangers for automotive sector: Numerical simulations of heat transfer and flow resistance coping with industrial constraints

Louvered fins perform better than any other geometry in accomplishing the task of enhancing heat transfer of compact heat exchangers without prohibitive costs and pressure drops. For this reason they are widely adopted for automotive applications. However, in order to improve louvered-fin compact heat exchangers, it is strongly required to understand how louvered fins behave regarding both heat transfer and pressure drop taking into account industrial constraints. For this purpose, numerical simulations based on the equations of thermo-fluid-dynamics have been developed for this study. In particular, boundary heat flux and pressure distributions have been analyzed along the louvered fin assembly and around the louvers, and even the effects of the flat portions (central and lateral louvers) have been investigated. In particular, the effects of the main geometrical parameters, such as fin pitch, louver pitch, and louver angle, have been evaluated by performing simulations on 40 different configurations. The results show that there is not one optimum configuration for the heat exchangers. Finally, a detailed procedure for the optimisation of louvered-fin compact heat exchangers, considering industrial constraints is suggested according to multiple regression technique of the numerical results.