Enhancing the thermal hydraulic performance on the air side of finned tube heat exchangers through superhydrophilic–superhydrophobic striped patterns

• A new finned tube heat exchanger (FTHE-SSSP) was proposed and designed. • The stripe-patterned surfaces with optimal performance were determined. • The effectiveness of the FTHE-SSSP in enhancing heat transfer was analysed. • The thermal hydraulic performance of FTHE-HHS was investigated. Condensate on fins deteriorates the air-side performance of finned tube heat exchangers (FTHEs) under wet conditions. To enhance the thermal hydraulic performance of FTHEs, a new finned tube heat exchanger with a superhydrophilic–superhydrophobic stripe pattern (FTHE-SSSP) is proposed by combining the advantages of superhydrophilic and superhydrophobic stripe surfaces in condensation heat transfer. Twelve superhydrophilic–superhydrophobic stripe pattern surfaces were designed by varying the stripe angle α and stripe width W , and heat and mass transfer models of the FTHE-SSSPs were established. The effects of different stripe patterns on the air-side performance of the FTHE-SSSPs were investigated numerically, and stripe-patterned surfaces with optimal performance were determined. Moreover, the effectiveness of the proposed FTHE-SSSPs in enhancing heat transfer was compared and analysed with that of a hydrophilic FTHE. The results show that the heat transfer factor j h and mass transfer factor j m of the FTHE-SSSP are more sensitive to the variation parameters of the stripe pattern when the stripe angle α is 60° or the stripe width W is 1 mm. The optimal combination pattern of α and W , in which the stripe angle α is 60° and the stripe width W is 1 mm, has the optimal thermal performance, and compared with the hydrophilic FTHE, its j h -factor, j m -factor and thermal–hydraulic performance j h / f 1/3 are improved by an average of 20.83 %, 21.77 % and 22.17 %, respectively. The friction factor f is reduced by an average of 1.11 %, and the dehumidification capacity per fin area is improved by an average of 12.18 % at different inlet air velocity, indicating that it has better air-side performance.