Spontaneous breakup of charged and uncharged water drops freely suspended in a wind tunnel

Abstract

Time for which charged or uncharged water drops of different sizes can be suspended over a vertical wind tunnel before their spontaneous breakup and the size distribution of droplets resulting from their breakup have been determined. Probability of spontaneous breakup of a drop has been found to increase with the size and charge of the drop. It has been observed that water drops carrying a charge of 5 × 10^-10 C breakup immediately after their suspension if their diameter > 8 mm. Total number of droplets produced on spontaneous breakup of a drop increases with the size of the drop, and if the drop size is > 6.6 mm, the total number of droplets is more when the drop is uncharged than that when it is charged. However, the number of droplets larger than a critical size is more if the parent drop is charged and the number of droplets smaller than that critical size is more if the parent drop is uncharged. It has been attempted to qualitatively explain the experimental results as the result of enhanced surface charge density around the waist of the drop during its oscillation. Charge on the drop has been suggested to cause an increase in width of the base of suspended drop.