The Effect of Resting Time on the Shedding of a Drop

Abstract

The shedding of an oil drop due to gradually increasing water shear flow is studied for different resting times. Resting time is the duration of the drop after placing on a surface and before starting the flow. Acrylic surface is chosen. Applied drag balances the adhesion, and the drop starts to shed. The velocity of the water flow right at that point is called the critical velocity of shedding of the drop. The velocity is found to be higher for the drops with higher resting times. Result shows that the contact length becomes higher for drops with higher resting times, making the adhesion to be higher. Therefore, higher drag becomes necessary for the drop to shed. So, the critical velocity increases. In general, the velocity is found to decrease with the increase in the drop volume. Deformation and crawling are observed when a drop sheds.