Boundary integral prediction of the spreading of an inviscid drop impacting on a solid surface

Abstract

Axisymmetric spreading of an idealised inviscid liquid drop impinging on a horizontal solid surface is analysed (including surface tension) using a boundary integral method for Weber numbers (We), based on initial drop radius and impact velocity, ranging from 3 to 100. Progressive accumulation of liquid in a rim around the periphery of the spreading inviscid drop is predicted. The effect diminishes with increasing Weber number, and is negligible when We = 50. It is concluded that the experimentally observed rim at Weber numbers exceeding this value is due solely to viscous retardation. For We ≥ 10, the calculated reduction in drop height with time is found to be almost independent of Weber n..