Clinching 1/2 scaling: Deciphering spreading data of droplet impact

Although the scaling law We${}^{1/2}$ where We is the Weber number for describing the maximum spreading of an impacting drop in the capillary regime has been validated by subsequent works, the We${}^{1/4}$ scaling persists in the literature. We found not only viscous dissipation but also the initial diameter result in the gap. Taking the initial diameter and wettability into account, a generalized scaling for the drop's maximum spreading is established, showing excellent agreement with data for both low and relatively high We.