Influences of water droplet size and contact angle on the electric field and potential distributions on an insulator surface

Existence of water droplets on an outdoor high voltage insulator surface changes the electric field flux and its equipotential distribution. The water droplets may appear in different forms and sizes, therefore the form is defined by the angle shape between the surface of the water droplet and that of the insulator surface, and the size is specified by the radii. The water droplet may measure from less than 90 degree (hydrophilic) up to greater than 90 degree (hydrophobic), depending on the properties of insulator surface. The work here presented describes numerical analysis calculation of electric fields and its potential distribution in the surrounding of water droplets on an insulator surface. The computation has been done using a partial differential equation toolbox, which worked based on the finite element method. The parameters used in this numerical analysis were the contact angle and the size of the water droplets. The computation results showed that the electric field close to the water droplets tends to be higher as its radius increases. The electric field fluxes were also affected slightly by the contact angle.