Numerical simulation of the performance of a dehumidifier section in an <scp>humidification–dehumidification method</scp> desalination system combined with <scp>thermoelectric</scp> modules for an innovative fin geometry design

Abstract Water scarcity necessitates efficient desalination technologies compatible with limited energy resources. This study employs CFD to optimize thermoelectric‐based dehumidifier performance in open‐cycle humidification–dehumidification desalination systems. Numerical simulations utilizing the mixture multiphase model and realizable k‐ε turbulence model evaluated four fin configurations: simple fins and fins with circular, triangular, and square protrusions. At 309.15 K inlet temperature, the circular protrusion geometry achieved maximum water production of 126.65 g/h, followed by triangular (119.42 g/h), square (117.43 g/h), and simple fin designs (114.94 g/h). The circular configuration demonstrated a GOR of 0.57, representing a 24% increase in thermal efficiency compared to the baseline simple fin (GOR = 0.46). Despite requiring only 3.9% additional material mass, the circular design achieved the highest normalized water production of 1.327 g/h per gram of fin mass, outperforming triangular (1.262), simple (1.251), and square (1.249) configurations. Performance enhancement resulted from increased heat transfer area, elevated turbulent kinetic energy in protrusion regions, and improved thermal boundary layer disruption. These findings demonstrate that optimized fin geometry, particularly designs incorporating circular protrusions, can substantially enhance water production efficiency in HDH systems, highlighting the critical role of heat sink design optimization in improving overall system performance.