Drag reduction mechanism and aerodynamic characteristics of a newly developed overhead electric wire

A new type of electric wire for overhead transmission lines is developed to reduce the drag force under a typhoon condition. The drag reduction mechanism was studied with a water experiment, which allows the time scale of the experiment to expand about 100 times larger than that of an actual phenomenon in air under Re number similitude. The aerodynamic characteristics regarding the mean drag coefficient were also extensively studied in wind tunnel experiments, including effects of wind velocity, wind incident angle, surface roughness and turbulence intensity.