Enhanced desalination performance under low-pressure conditions using swirling impeller-induced turbulence: A comprehensive 3D CFD simulation study towards sustainable water solutions

Traditional thermal desalination systems, constrained by high energy input, benefit significantly from operating under low-pressure, sub-atmospheric conditions. However, phase change kinetics often limit efficiency. This study addresses the critical need for energy-efficient phase enhancement methods in low-pressure distillation to accelerate the global deployment of sustainable water technologies. The primary objective of this investigation is to meticulously quantify and elucidate the profound enhancement of evaporation kinetics achieved by strategically introducing a highly controlled turbulent swirling flow in a low-pressure ( 7300 Pa ) evaporator chamber, providing actionable insights for next-generation system design. A comprehensive three-dimensional Computational Fluid Dynamics (CFD) framework utilizing the Volume of Fluid (VOF) model and the Lee phase-change model was implemented in ANSYS Fluent. Turbulence was induced using calibrated volumetric momentum source terms , explicitly derived to emulate the effect of a physical impeller operating at an equivalent mechanical power input of 43.0 W . The study included rigorous mesh independence and model sensitivity analyses . The controlled turbulence resulted in a marked increase in the desalination rate, soaring from a quiescent baseline of 18 g/min to a highly significant 128.3 g/min . This enhancement represents a 613% improvement in productivity for a parasitic mechanical energy load that accounts for only 0.83% of the total system power. The work confirms turbulence-enhanced evaporation as an exceptionally viable and potent strategy for improving low-pressure desalination efficiency.