An Experimental Study of Atmospheric Icing Process on Power Transmission Line 2019-01-2019

Atmospheric icing poses a major threat to power transmission lines in cold regions. In the present study, an experimental investigation was conducted to examine the atmospheric icing process on high-voltage power transmission lines and characterize the effects of the ice accretion on the aerodynamic forces acting on the transmission lines. The experimental study was conducted in the Icing Research Tunnel available at Iowa State University (ISU-IRT). A cylinder model with the same diameter of commonly-used high-voltage power transmission lines (i.e., D = 29mm) is subjected to a typical glaze icing condition at an incoming wind speed of 20 m/s, a liquid water content (LWC) of 2.0 g/m³ and an ambient temperature of -5 ⁰C. A high-resolution 3D scanner was used in the present study to extract the 3D shapes of the ice structures accreted over surface of the cylindrical test model as a function of the ice accretion time. While the aerodynamic drag force acting on the test model was measured by using a force transducer during the dynamic ice accreting process, a high-resolution Particle Image Velocimetry (PIV) system was also used to quantify the characteristics of the wake flow behind the test model. It was found that, the drag coefficient of the test model reduced by about 30% during the initial phase of the icing process, and then increased continuously throughout the rest of the icing event. The aerodynamic force measurement results were correlated with the PIV flow field measurements to elucidate the underlying physics.