Drag Reduction of Metastable, Superhydrophobic Silicone Rubber Surfaces

In recent years, silicone rubber has been extensively employed in the medical field, particularly playing a significant role in the fabrication of catheters, implants, seals, and medical tubing. This study uses a systematic methodology combining computational fluid dynamics (CFD) simulations with rheological experiments to deeply investigate the drag reduction performance of four types of micro/nanostructured superhydrophobic silicone rubber surfaces. CFD simulations reveal the evolution mechanism and dynamic characteristics of gas-liquid two-phase flow over these structured surfaces, providing preliminary predictions of their drag reduction performances and elucidating underlying physical mechanisms. Subsequently, simulation results are validated through rheological experiments. Finally, the correlation between surface wettability and drag reduction performance is analyzed. The results demonstrate that experimentally measured drag reduction rates remarkably agree with simulation predictions, with deviations within only 3.4%. This strongly confirms the numerical model's accuracy and reliability, offering solid data and theoretical support for the drag-reduction mechanism of superhydrophobic surfaces. The antibiofouling properties, biocompatibility, and long-term stability of the structured surfaces have been experimentally confirmed.