Synergistic experimental and CFD study on aerodynamic characteristics and flow field evolution mechanisms of iced eight-bundled conductors

Abstract Ultra-high transmission is at risk in cold climates. This is because of the aerodynamic instability of iced eight-bundled conductors. This study looked into how flow instability happens with real crescent- and sector-shaped ice accretions. A combination of wind tunnel experiments and CFD simulations was used. The models were tested with wind coming from 0° to 180°. Force coefficients and flow field details were analyzed. Sector-shaped icing creates larger, more nonlinear changes in lift and drag coefficients. This is compared to the crescent shape. For example, the maximum lift coefficient for the sector shape is 1.54. This is more than twice the crescent shape’s value. The maximum drag coefficient is 2.85, a large increase from 1.89 for the crescent shape. Abrupt changes at critical attack angles are connected to strong flow separation and vortex interactions. There was good agreement between the experiments and the simulations. The mean absolute error for the lift coefficient was around 0.15. For the drag coefficient, it was about 0.18. Some differences did exist, though. These were likely due to simplified ice geometry. The SST k - ω turbulence model was also a factor. It was found that both ice morphology and wind direction strongly influence aerodynamic stability. Using both experimental and CFD methods gives a deeper understanding of the flow mechanisms. These findings can help improve anti-galloping design. They also improve the reliability of transmission lines in icing conditions.