Aerodynamic and aeroelastic wind tunnel model tests of overhead power lines in triangular configuration under different icing conditions

Abstract

This paper describes the experimental model tests conducted in the boundary layer wind tunnel of the Wind Engineering Laboratory of Cracow University of Technology. The tests were focused on overhead power line conductors arranged in triangular bundles under different types of icing. Five representative cases of snow, ice and rime/frost loads were assumed on the basis of examples defined in literature and field studies. A dimensional analysis was conducted for the case studies. The experimental model tests were conducted in two independent series. Each series required sectional models of different features. The results of the first series were in the form of mean aerodynamic coefficients Cx, Cz and Cm for selected cases of snow, ice and rime/frost conductors covers. On this basis, aerodynamic interferences of overhead line conductors were determined. The model tests were performed on a rigid sectional model of conductors. The second series was aimed at the identification of aeroelastic phenomena caused by interference of the conductors. As a result, the critical velocity of conductors galloping and wake galloping for selected cases of snow, ice and rime/frost covers was determined. For this series of tests, a sectional aeroelastic model (rigid sectional model of each cable with flexible supports at the ends) of the three-cable bundled conductors was made.