Numerical Simulation of Aerodynamic Coefficients of Iced-Quad Bundle Conductors

Two-dimensional air flows around a quad bundle conductor covered with crescent-shaped ice of different thickness are numerically simulated, based on which the aerodynamic coefficients of each iced subconductor vary with the angle of wind attack are determined. The numerically obtained aerodynamic coefficients are compared with those by the wind tunnel test carried out previously. It is seen that the laws of the aerodynamic coefficients against the angle of attack determined by the two methods are similar, and the corresponding Den Hartog coefficients and Nigol coefficients agree well. Moreover, the galloping frequencies, vibration modes, and galloping traces of a typical iced-quad bundle conductor line obtained by the finite-element method based on the aerodynamic coefficients, respectively, determined by the two methods are similar even though their vibration amplitudes are somewhat different. It is demonstrated that the aerodynamic coefficients determined by numerical simulation can be used to investigate galloping behavior and anti-galloping techniques of overhead transmission lines.