| In cold regions, overhead line cables and their supporting structures are usually fully exposed to atmospheric icing. In addition, rising temperatures due to climate changes are expected to increase the risks associated with extreme weather events which in turn could possibly increase the frequency and severity of storms such as winter blizzards and ice storms.;Atmospheric icing is one of the major problems in cold climate regions, which can cause serious damage to transmission line structures, such as overhead transmission networks. Towers or pylons, usually steel lattice structures, represent an important part of the cost of transmission lines.;Ice deposits on exposed structures can be the source of several mechanical problems. On transmission line towers in particular, the loads due to heavy ice accretion, coupled with wind-on-ice loads, may lead to aerodynamic effects and cause structural damages, or failure and even cascading collapse of towers.;The present investigation is mainly focused on the study of aerodynamic characteristics of angle member icing. The objective is to understand the influence of ice accretion on drag, lift and moment in respect to different ice profiles. In most of the previous experimental studies of ice effects on aerodynamic characteristics, aerodynamic bodies such as airfoils and wings were modeled, whereas in this research, the ice effects on bluff bodies is studied.;Experimental models that explicitly consider different glaze ice profiles by including the thermo-physical properties of ice during accretion are proposed. Drag, lift and moment coefficient of those angle member reproduced using cement molded glaze ice profiles are thus measured in a wind tunnel.;The models serve as a basis to study various criteria of atmospheric glaze ice effects in terms of aerodynamic coefficient and, aerodynamic forces. Various tower section geometries with glaze ice profiles can also be readily investigated using these models. Several aerodynamic scenarios of an angle member are simulated in order to investigate how variables including ice thickness, liquid water content (LWC), droplet size distribution (DSD) and Reynolds number affect the drag, lift and moment coefficients of an iced angle member subjected to air velocity.;Ice morphology of an angle member for different aerodynamic angles and different model orientations are also explored in order to study the flow characteristics effects on ice accretion. |
