Numerical study and optimization of water droplet impact on superhydrophobic surfaces with trapezoidal ridge texture

In this study, a three-dimensional numerical model for the characteristic of water droplet impact on a superhydrophobic surface modified with trapezoidal ridge textures is established. The study investigates the dynamic evolution of impacting droplet and the influence of texture structural parameters on the critical Weber number (We) for pancake bouncing and the corresponding contact time. Constraining the effects of texture structural parameters on the critical Weber number and contact time, and taking these two as performance indicators, a dual-objective optimization model was constructed using the Non-dominated Sorting Genetic Algorithm II (NSGA-II) algorithm. Numerical simulation results reveal that the critical Weber number and the corresponding contact time exhibit opposite evolutionary trends with changes in the texture structural parameters. Specifically, the critical Weber number decreases with an increase in center-to-center spacing and ridge height but increases with the growth of ridge top length and ridge bottom length. Numerical recalculations were conducted based on three groups of optimized solutions under limited target conditions, demonstrating that the dual-objective optimization model effectively optimizes the parameters of trapezoidal ridge textures.