Abstract
A new conductor of low-wind drag type with an 18-polygonal cross-section for overhead transmission line has been developed. Aerodynamic characteristics of the conductor regarding the mean drag coefficient were studied by wind tunnel tests, including effects of wind speed and turbulence intensity. As a result, 50% reduction of drag coefficient has been achieved under designing wind speed condition. The mechanism of wind drag reduction of the conductor was also studied by flow visualization tests in a water tunnel based on Reynolds similarity law. The flow visualization test revealed that “drag crisis” arises in the flow around the new conductor by effects of polygonal cross-section at Reynolds number an order of magnitude lower than that of a smooth circular cylinder.
