Investigation of supercooled water droplet sticking efficiency during power transmission line icing using digital holography

Transmission line icing severely threatens the safety of the power grid. Accurate prediction of the sticking efficiency (the proportion of supercooled droplets that remain on the conductor after impact, excluding bouncing and splashing) is critical for preventing and mitigating icing disasters. Traditional prediction models for sticking efficiency typically exhibit significant errors under complex conditions (e.g., varying wind speeds and precipitation intensities), thereby limiting their practical applications. To overcome this limitation, a two-stage coupled model based on coaxial digital holography was proposed. In this model, the diameters, velocities, and collision angles of supercooled droplets were accurately measured and incorporated into a two-stage framework that couples droplet impact dynamics with thermodynamic processes to calculate sticking efficiency. For the laboratory and field-validation cases examined in this study, the prediction errors of the proposed model remained below 3.5 % under various conditions, representing a significant improvement over traditional models and underscoring its enormous potential in engineering applications.