The effect of droplet size and liquid water content on ice accretion and aerodynamic coefficients of tower legs

An experimental study was conducted to examine the effects of varying the cloud characteristics on ice accretion on tower legs and on the aerodynamic coefficients around the ice-covered legs. First, the variations of droplet size distribution (DSD) and liquid water content (LWC) in vertical and streamwise directions were measured. Then, variations of ice accretion on an angle bar in the same direction as the flow were measured to determine the aerodynamic forces on a tower leg as a function of ice accretion. The ice accretion experiments were carried out under two conditions with different LWCs and air velocities. The drag coefficient was calculated with different masses and ice shapes for the angle bar as obtained in the experiments. The results showed a reduction in the drag coefficient in the vertical direction with increased local LWC and thicker ice accumulation.