Abstract
Galloping is a typical wind-induced phenomenon in iced conductors, which can have serious impacts on the safe and stable operation of power systems. The aerodynamic characteristics of an iced conductor are the key factor in the study of galloping, which can be determined mainly by the numerical simulation of flow past an iced conductor. Based on the Reynolds-averaged Navier-Stokes (RANS) equations closed by the Spalart-Allmaras (S-A) turbulence model, the third-order Runge-Kutta method along the uniform streamline and Galerkin method are used for temporal and spatial discretization, respectively. The convection and diffusion terms in the discretization scheme are treated semi-implicitly, and the finite element scheme based on the S-A turbulence model is presented and used to numerically simulate flow past a crescent iced conductor. We systematically investigate the effects of icing thickness, wind speed, and wind attack angle on aerodynamic coefficients and flow patterns. Based on the experimental results, the effectiveness of the present algorithm is verified. Using the streamline diagram and pressure distribution diagram of the crescent-shaped iced conductor, the mechanism for the sharp peak of the lift coefficient is explored. Combined with the galloping mechanism of Den Hartog and Nigol, the galloping instability zone of the crescent-shaped iced conductor is analyzed.